1
|
Shirley AM, Vallad GE, Quesada-Ocampo L, Dufault N, Raid R. Effect of Cucurbit Host, Production Region, and Season on the Population Structure of Pseudoperonospora cubensis in Florida. Plant Dis 2024; 108:442-450. [PMID: 37642548 DOI: 10.1094/pdis-12-22-2939-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Pseudoperonospora cubensis, the causal agent of Cucurbit downy mildew (CDM), is one of the most important diseases affecting cucurbit production in the United States. This disease is especially damaging to Florida production areas, as the state is a top producer of many cucurbit species. In addition, winter production in central and south Florida likely serves as a likely source of P. cubensis inoculum for spring and summer cucurbit production throughout the eastern United States, where CDM is unable to overwinter in the absence of a living host. Over 2 years (2017 and 2018) and four seasons (spring 2017, spring 2018, fall 2017, and fall 2018), 274 P. cubensis isolates were collected from cucurbit hosts at production sites in south, central, and north Florida. The isolates were analyzed with 10 simple sequence repeat (SSR) markers to establish population structure and genetic diversity and further assigned to a clade based on a qPCR assay. Results of population structure and genetic diversity analyses differentiated isolates based on cucurbit host and clade (1 or 2). Of the isolates assigned to clade by qPCR, butternut squash, watermelon, and zucchini were dominated by clade 1 isolates, whereas cucumber isolates were split 34 and 59% between clades 1 and 2, respectively. Clade assignments agreed with isolate clustering observed within discriminant analysis of principal components (DAPC) based on SSR markers, although watermelon isolates formed a group distinct from the other clade 1 isolates. For seasonal collections from cucumber at each location, isolates were typically skewed to one clade or the other and varied across locations and seasons within each year of the study. This variable population structure of cucumber isolates could have consequences for regional disease management. This is the first study to characterize P. cubensis populations in Florida and evaluate the effect of cucurbit host and clade-type on isolate diversity and population structure, with implications for CDM management in Florida and other United States cucurbit production areas.
Collapse
Affiliation(s)
- Andrew M Shirley
- Department of Plant Pathology, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598
| | - Gary E Vallad
- Department of Plant Pathology, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598
| | - Lina Quesada-Ocampo
- Department of Entomology and Plant Pathology and NC Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27695-7825
| | - Nicholas Dufault
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Richard Raid
- Department of Plant Pathology, Everglades Research and Education Center, University of Florida, Belle Glade, FL 33430
| |
Collapse
|
2
|
Peng J, Wang X, Wang H, Li X, Zhang Q, Wang M, Yan J. Advances in understanding grapevine downy mildew: From pathogen infection to disease management. Mol Plant Pathol 2024; 25:e13401. [PMID: 37991155 PMCID: PMC10788597 DOI: 10.1111/mpp.13401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 09/29/2023] [Indexed: 11/23/2023]
Abstract
Plasmopara viticola is geographically widespread in grapevine-growing regions. Grapevine downy mildew disease, caused by this biotrophic pathogen, leads to considerable yield losses in viticulture annually. Because of the great significance of grapevine production and wine quality, research on this disease has been widely performed since its emergence in the 19th century. Here, we review and discuss recent understanding of this pathogen from multiple aspects, including its infection cycle, disease symptoms, genome decoding, effector biology, and management and control strategies. We highlight the identification and characterization of effector proteins with their biological roles in host-pathogen interaction, with a focus on sustainable control methods against P. viticola, especially the use of biocontrol agents and environmentally friendly compounds.
Collapse
Affiliation(s)
- Junbo Peng
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Xuncheng Wang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Hui Wang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Xinghong Li
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Qi Zhang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Meng Wang
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| | - Jiye Yan
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North ChinaInstitute of Plant Protection, Beijing Academy of Agriculture and Forestry SciencesBeijingChina
| |
Collapse
|
3
|
Ling Y, Xiong X, Yang W, Liu B, Shen Y, Xu L, Lu F, Li M, Guo Y, Zhang X. Comparative Analysis of Transcriptomics and Metabolomics Reveals Defense Mechanisms in Melon Cultivars against Pseudoperonospora cubensis Infection. Int J Mol Sci 2023; 24:17552. [PMID: 38139381 PMCID: PMC10743968 DOI: 10.3390/ijms242417552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/10/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023] Open
Abstract
Melon (Cucumis melo L.) represents an agriculturally significant horticultural crop that is widely grown for its flavorful fruits. Downy mildew (DM), a pervasive foliar disease, poses a significant threat to global melon production. Although several quantitative trait loci related to DM resistance have been identified, the comprehensive genetic underpinnings of this resistance remain largely uncharted. In this study, we utilized integrative transcriptomics and metabolomics approaches to identify potential resistance-associated genes and delineate the strategies involved in the defense against DM in two melon cultivars: the resistant 'PI442177' ('K10-1') and the susceptible 'Huangdanzi' ('K10-9'), post-P. cubensis infection. Even in the absence of the pathogen, there were distinctive differentially expressed genes (DEGs) between 'K10-1' and 'K10-9'. When P. cubensis was infected, certain genes, including flavin-containing monooxygenase (FMO), receptor-like protein kinase FERONIA (FER), and the HD-ZIP transcription factor member, AtHB7, displayed pronounced expression differences between the cultivars. Notably, our data suggest that following P. cubensis infection, both cultivars suppressed flavonoid biosynthesis via the down-regulation of associated genes whilst concurrently promoting lignin production. The complex interplay of transcriptomic and metabolic responses elucidated by this study provides foundational insights into melon's defense mechanisms against DM. The robust resilience of 'K10-1' to DM is attributed to the synergistic interaction of its inherent transcriptomic and metabolic reactions.
Collapse
Affiliation(s)
- Yueming Ling
- Hami-Melon Research Center, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; (Y.L.); (W.Y.); (B.L.); (Y.S.); (L.X.); (M.L.)
| | - Xianpeng Xiong
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Synthetic Biology, Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China;
| | - Wenli Yang
- Hami-Melon Research Center, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; (Y.L.); (W.Y.); (B.L.); (Y.S.); (L.X.); (M.L.)
| | - Bin Liu
- Hami-Melon Research Center, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; (Y.L.); (W.Y.); (B.L.); (Y.S.); (L.X.); (M.L.)
| | - Yue Shen
- Hami-Melon Research Center, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; (Y.L.); (W.Y.); (B.L.); (Y.S.); (L.X.); (M.L.)
- College of Horticulture, Xinjiang Agricultural University, Urumqi 830091, China
| | - Lirong Xu
- Hami-Melon Research Center, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; (Y.L.); (W.Y.); (B.L.); (Y.S.); (L.X.); (M.L.)
- College of Horticulture, Xinjiang Agricultural University, Urumqi 830091, China
| | - Fuyuan Lu
- College of Agriculture, Shihezi University, Shihezi 832003, China;
| | - Meihua Li
- Hami-Melon Research Center, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; (Y.L.); (W.Y.); (B.L.); (Y.S.); (L.X.); (M.L.)
| | - Yangdong Guo
- College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Xuejun Zhang
- Hami-Melon Research Center, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; (Y.L.); (W.Y.); (B.L.); (Y.S.); (L.X.); (M.L.)
- College of Horticulture, China Agricultural University, Beijing 100193, China
- Hainan Sanya Experimental Center for Crop Breeding, Xinjiang Academy of Agricultural Sciences, Sanya 572019, China
| |
Collapse
|
4
|
Maurer D, Sadeh A, Chalupowicz D, Barel S, Shimshoni JA, Kenigsbuch D. Hydroponic versus soil-based cultivation of sweet basil: impact on plants' susceptibility to downy mildew and heat stress, storability and total antioxidant capacity. J Sci Food Agric 2023; 103:7809-7815. [PMID: 37453104 DOI: 10.1002/jsfa.12860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/10/2023] [Accepted: 07/15/2023] [Indexed: 07/18/2023]
Abstract
BACKGROUND In recent years, hydroponically cultivated basil has gained extensive popularity over soil-based cultivation. Evidence for potential differences between both cultivation methods, in terms of resistance to biotic and abiotic stress factors, storage properties and shelf-life, is still lacking and the potential effect of cultivation method on the antioxidant capacity has not yet been fully explored. This study aimed to determine which of the two basil cultivation methods produces plants that are more resilient to downy mildew and external heat treatment and that exhibit better storage and shelf-life performance. RESULTS Hydroponically grown basil was significantly more affected by browning than the soil-grown basil at the end of the storage and end of the shelf-life period. Under both cultivation methods, the extent of browning increased significantly between the end of the storage and end of the shelf-life period, by a factor of 1.4. Moreover, hydroponically grown plants were significantly more sensitive to heat treatment than soil-grown basil. However, the soil-grown basil exhibited significantly greater susceptibility to downy mildew than the hydroponically grown basil. At harvest, and at the end of the storage period, the antioxidant capacity of hydroponically cultivated basil was significantly greater than that of soil-grown basil. CONCLUSIONS Hydroponically cultivated basil exhibited greater resistance to downy mildew, but less resilience to heat and browning during storage and a shelf-life period, resulting in poorer storage and shelf-life performance as compared to soil-cultivated basil. The greater total antioxidant capacity of the hydroponically cultivated basil seems to be the major cause for the observed phenomena. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- Dalia Maurer
- Department of Postharvest Science, Institute for Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Alona Sadeh
- Department of Postharvest Science, Institute for Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Daniel Chalupowicz
- Department of Postharvest Science, Institute for Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Shimon Barel
- Department of Toxicology, Kimron Veterinary Institute, Bet Dagan, Israel
| | - Jakob A Shimshoni
- Department of Food Science, Institute for Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - David Kenigsbuch
- Department of Postharvest Science, Institute for Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| |
Collapse
|
5
|
Richardson BJ, Gent DH. Impact of Infection Timing and Autumnal Fungicide Applications on Perennation of Pseudoperonospora humuli and Severity of Hop Downy Mildew. Plant Dis 2023; 107:3430-3436. [PMID: 37079010 DOI: 10.1094/pdis-02-23-0268-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Pseudoperonospora humuli, causal agent of hop downy mildew, is known to survive winter as systemic mycelium in the crown and developing buds of hop (Humulus lupulus). Field studies were conducted over three growing seasons to quantify the association of infection timing to overwintering of P. humuli and development of downy mildew. Cohorts of potted plants were inoculated sequentially from early summer to autumn, overwintered, and then evaluated for symptoms of systemic downy mildew in emerging shoots. Shoots with systemic P. humuli developed after inoculation at any time in the previous year, with the most severe disease typically resulting from inoculation in August. Independent of the timing of inoculation, diseased shoots emerged coincident with the emergence of healthy shoots, beginning as early as late February and continuing through late May to early June. Surface crown buds on inoculated plants exhibited internal necrosis associated with P. humuli at rates ranging from 0.3 to 1.2%, whereas P. humuli was detected by PCR on 7.8 to 17.0% of asymptomatic buds depending on the timing of inoculation and year. Four experiments were conducted to quantify the impact of foliar fungicides applied in autumn on downy mildew the following spring. There was a small reduction of disease in only one study. Together, these studies indicate that infection by P. humuli that leads to overwintering can occur over a broad period of time, but delaying infection until autumn tends to reduce disease levels in the following year. However, in established plantings, postharvest application of foliar fungicides appeared to have little impact on severity of downy mildew in the ensuring year.
Collapse
Affiliation(s)
- Briana J Richardson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - David H Gent
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
- Forage Seed and Cereal Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Corvallis, OR 97331
| |
Collapse
|
6
|
Chen Y, Miao L, Li X, Liu Y, Xi D, Zhang D, Gao L, Zhu Y, Dai S, Zhu H. Comparative Transcriptome Analysis between Resistant and Susceptible Pakchoi Cultivars in Response to Downy Mildew. Int J Mol Sci 2023; 24:15710. [PMID: 37958694 PMCID: PMC10649052 DOI: 10.3390/ijms242115710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/09/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Downy mildew caused by the obligate parasite Hyaloperonospora brassicae is a devastating disease for Brassica species. Infection of Hyaloperonospora brassicae often leads to yellow spots on leaves, which significantly impacts quality and yield of pakchoi. In the present study, we conducted a comparative transcriptome between the resistant and susceptible pakchoi cultivars in response to Hyaloperonospora brassicae infection. A total of 1073 disease-resistance-related differentially expressed genes were identified using a Venn diagram. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that these genes were mainly involved in plant-pathogen interaction, plant hormone signal transduction, and other photosynthesis-related metabolic processes. Analysis of the phytohormone content revealed that salicylic acid increased significantly in the resistant material after inoculation with Hyaloperonospora brassicae, whereas the contents of jasmonic acid, abscisic acid, and 1-aminocyclopropane-1-carboxylic acid decreased. Exogenous salicylic acid treatment also significantly upregulated Hyaloperonospora brassicae-induced genes, which further confirmed a crucial role of salicylic acid during pakchoi defense against Hyaloperonospora brassicae. Based on these findings, we suggest that the salicylic-acid-mediated signal transduction contributes to the resistance of pakchoi to downy mildew, and PAL1, ICS1, NPR1, PR1, PR5, WRKY70, WRKY33, CML43, CNGC9, and CDPK15 were involved in this responsive process. Our findings evidently contribute to revealing the molecular mechanism of pakchoi defense against Hyaloperonospora brassicae.
Collapse
Affiliation(s)
- Yaosong Chen
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai 201418, China
| | - Liming Miao
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Xiaofeng Li
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Yiwen Liu
- Institute of Agricultural Science and Technology Information, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
| | - Dandan Xi
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Dingyu Zhang
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Lu Gao
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Yuying Zhu
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| | - Shaojun Dai
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai 201418, China
| | - Hongfang Zhu
- Shanghai Key Laboratory of Protected Horticultural Technology, Horticulture Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (Y.C.)
| |
Collapse
|
7
|
Bolzonello A, Morbiato L, Tundo S, Sella L, Baccelli I, Echeverrigaray S, Musetti R, De Zotti M, Favaron F. Peptide Analogs of a Trichoderma Peptaibol Effectively Control Downy Mildew in the Vineyard. Plant Dis 2023; 107:2643-2652. [PMID: 36724095 DOI: 10.1094/pdis-09-22-2064-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Plasmopara viticola, the agent of grapevine downy mildew, causes enormous economic damage, and its control is primarily based on the use of synthetic fungicides. The European Union policies promote reducing reliance on synthetic plant protection products. Biocontrol agents such as Trichoderma spp. constitute a resource for the development of biopesticides. Trichoderma spp. produce secondary metabolites such as peptaibols, but the poor water solubility of peptaibols limits their practical use as agrochemicals. To identify new potential bio-inspired molecules effective against P. viticola, various water-soluble peptide analogs of the peptaibol trichogin were synthesized. In grapevine leaf disk assays, the peptides analogs at a concentration of 50 μM completely prevented P. viticola infection after zoosporangia inoculation. Microscopic observations of one of the most effective peptides showed that it causes membrane lysis and cytoplasmic granulation in both zoosporangia and zoospores. Among the effective peptides, 4r was selected for a 2-year field trial experiment. In the vineyard, the peptide administered at 100 μM (equivalent to 129.3 g/ha) significantly reduced the disease incidence and severity on both leaves and bunches, with protection levels similar to those obtained using a cupric fungicide. In the second-year field trial, reduced dosages of the peptide were also tested, and even at the peptide concentration reduced by 50 or 75%, a significant decrease in the disease incidence and severity was obtained at the end of the trial. The peptide did not show any phytotoxic effect. Previously, peptide 4r had been demonstrated to be active against other fungal pathogens, including the grapevine fungus Botrytis cinerea. Thus, this peptide may be a candidate for a broad-spectrum fungicide whose biological properties deserve further investigation.
Collapse
Affiliation(s)
- Angela Bolzonello
- Department of Land, Environment, Agriculture, and Forestry (TESAF), University of Padova, Legnaro I-35020, Italy
| | - Laura Morbiato
- Department of Chemistry, University of Padova, Padova I-35131, Italy
| | - Silvio Tundo
- Department of Land, Environment, Agriculture, and Forestry (TESAF), University of Padova, Legnaro I-35020, Italy
| | - Luca Sella
- Department of Land, Environment, Agriculture, and Forestry (TESAF), University of Padova, Legnaro I-35020, Italy
| | - Ivan Baccelli
- Institute for Sustainable Plant Protection, National Research Council of Italy, Sesto Fiorentino I-50019, Italy
| | - Sergio Echeverrigaray
- Institute of Biotechnology, University of Caxias do Sul, Caxias do Sul, RS 95070-560, Brazil
| | - Rita Musetti
- Department of Land, Environment, Agriculture, and Forestry (TESAF), University of Padova, Legnaro I-35020, Italy
| | - Marta De Zotti
- Department of Chemistry, University of Padova, Padova I-35131, Italy
| | - Francesco Favaron
- Department of Land, Environment, Agriculture, and Forestry (TESAF), University of Padova, Legnaro I-35020, Italy
| |
Collapse
|
8
|
Asai S, Cevik V, Jones JDG, Shirasu K. Cell-specific RNA profiling reveals host genes expressed in Arabidopsis cells haustoriated by downy mildew. Plant Physiol 2023; 193:259-270. [PMID: 37307565 PMCID: PMC10469357 DOI: 10.1093/plphys/kiad326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/21/2023] [Accepted: 05/15/2023] [Indexed: 06/14/2023]
Abstract
The downy mildew oomycete Hyaloperonospora arabidopsidis, an obligate filamentous pathogen, infects Arabidopsis (Arabidopsis thaliana) by forming structures called haustoria inside host cells. Previous transcriptome analyses have revealed that host genes are specifically induced during infection; however, RNA profiling from whole-infected tissues may fail to capture key transcriptional events occurring exclusively in haustoriated host cells, where the pathogen injects virulence effectors to modulate host immunity. To determine interactions between Arabidopsis and H. arabidopsidis at the cellular level, we devised a translating ribosome affinity purification system using 2 high-affinity binding proteins, colicin E9 and Im9 (immunity protein of colicin E9), applicable to pathogen-responsive promoters, thus enabling haustoriated cell-specific RNA profiling. Among the host genes specifically expressed in H. arabidopsidis-haustoriated cells, we found genes that promote either susceptibility or resistance to the pathogen, providing insights into the Arabidopsis-downy mildew interaction. We propose that our protocol for profiling cell-specific transcripts will apply to several stimulus-specific contexts and other plant-pathogen interactions.
Collapse
Affiliation(s)
- Shuta Asai
- Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Volkan Cevik
- Department of Life Sciences, The Milner Centre for Evolution, University of Bath, Bath BA2 7AY, UK
| | | | - Ken Shirasu
- Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| |
Collapse
|
9
|
McGrath MT. Efficacy of Organic Fungicides for Downy Mildew in Field-Grown Sweet Basil. Plant Dis 2023; 107:2467-2473. [PMID: 36724027 DOI: 10.1094/pdis-10-22-2424-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Downy mildew is a common, widespread disease affecting basil leaves. No tolerance for disease symptoms, especially on leaves for fresh consumption, necessitates management. Six replicated experiments were conducted between 2010 and 2016 with field-grown basil of a susceptible cultivar exposed to naturally occurring, wind-dispersed sporangiospores of Peronospora belbahrii to evaluate fungicides approved for use on organically produced crops and products in development. Products tested currently registered for use on basil in the U.S. and labeled for downy mildew were Actinovate (Streptomyces lydicus), Companion (Bacillus subtilis), Cueva (copper octanoate), Double Nickel (Bacillus amyloliquefaciens), Forticept EP #1 (thyme oil), Milagrum Plus (Bacillus subtilis), Organocide (sesame oil), Oso (polyoxin D zinc salt), OxiDate (hydrogen dioxide), Procidic (citric acid), Regalia (Reynoutria sachalinensis extract), Stargus (Bacillus amyloliquefaciens), and Trilogy (neem oil). Most are biopesticides. A conventional fungicide, Revus (mandipropamid), was included in most experiments as a positive control. Applications were made weekly to foliage with a backpack sprayer starting before symptoms were seen, except in 2013 when disease onset was early and 2015 when applications were made twice weekly. Organic treatments tested in 2013 started with a soil drench application around the base of plants two days after transplantation. Fungicide efficacy was assessed based on incidence of symptomatic leaves rather than disease severity because there is no tolerance for disease on fresh-market herbs. None were effective based on weekly severity assessments or AUDPC values, confirming results from other researchers that downy mildew cannot be effectively managed with organic fungicides applied to susceptible basil cultivars.
Collapse
Affiliation(s)
- Margaret Tuttle McGrath
- Plant Pathology and Plant-Microbe Biology Section, SIPS, Cornell University, Long Island Horticultural Research and Extension Center, Riverhead, NY 11901
| |
Collapse
|
10
|
Pei X, Liu X, Zang C, Yu S, Xie J, Lin Y, Liang B, Wu X, Liang C. Genome Resource of Streptomyces atratus PY-1, a Broad-Spectrum Antimicrobial Strain in Particular Antagonistic Against Plasmopara viticola. Plant Dis 2023; 107:2506-2508. [PMID: 36774571 DOI: 10.1094/pdis-09-22-2093-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Streptomyces atratus PY-1 exhibited promising antimicrobial properties; in particular, it is highly inhibitory to Plasmopara viticola, which causes downy mildew of grape. It is very necessary to carry out systematic and in-depth research on the PY-1 strain for the improvement, application, and promotion of biocontrol agents. The PY-1 genome was fully sequenced and assembled. We present the draft genome sequence of PY-1, with a size of 9, 254, and 781 bp. Preliminary analysis on the PY-1 genome sequence shows that at least 35 gene clusters are involved in the biosynthesis of polyketides, terpenes, and nonribosomally synthesized peptides.
Collapse
Affiliation(s)
- Xue Pei
- Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Xiaozhou Liu
- Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
| | - Chaoqun Zang
- Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
| | - Shuyi Yu
- Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
| | - Jinhui Xie
- Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
| | - Ying Lin
- Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
| | - Bingbing Liang
- Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
| | - Xuehong Wu
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Chunhao Liang
- Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China
| |
Collapse
|
11
|
Nur M, Wood K, Michelmore R. EffectorO: Motif-Independent Prediction of Effectors in Oomycete Genomes Using Machine Learning and Lineage Specificity. Mol Plant Microbe Interact 2023; 36:397-410. [PMID: 36853198 DOI: 10.1094/mpmi-11-22-0236-ta] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Oomycete plant pathogens cause a wide variety of diseases, including late blight of potato, sudden oak death, and downy mildews of plants. These pathogens are major contributors to loss in numerous food crops. Oomycetes secrete effector proteins to manipulate their hosts to the advantage of the pathogen. Plants have evolved to recognize effectors, resulting in an evolutionary cycle of defense and counter-defense in plant-microbe interactions. This selective pressure results in highly diverse effector sequences that can be difficult to computationally identify using only sequence similarity. We developed a novel effector prediction tool, EffectorO, that uses two complementary approaches to predict effectors in oomycete pathogen genomes: i) a machine learning-based pipeline that predicts effector probability based on the biochemical properties of the N-terminal amino-acid sequence of a protein and ii) a pipeline based on lineage specificity to find proteins that are unique to one species or genus, a sign of evolutionary divergence due to adaptation to the host. We tested EffectorO on Bremia lactucae, which causes lettuce downy mildew, and Phytophthora infestans, which causes late blight of potato and tomato, and predicted many novel effector candidates while recovering the majority of known effector candidates. EffectorO will be useful for discovering novel families of oomycete effectors without relying on sequence similarity to known effectors. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Collapse
Affiliation(s)
- Munir Nur
- The Genome Center, University of California, Davis, CA, U.S.A
| | - Kelsey Wood
- The Genome Center, University of California, Davis, CA, U.S.A
- Integrative Genetics & Genomics Graduate Group, University of California, Davis, CA, U.S.A
| | - Richard Michelmore
- The Genome Center, University of California, Davis, CA, U.S.A
- Departments of Plant Sciences, Molecular & Cellular Biology, Medical Microbiology & Immunology, University of California, Davis, CA, U.S.A
| |
Collapse
|
12
|
Toporek SM, Branham SE, Keinath AP, Wechter WP. QTL mapping of resistance to Pseudo peronospora cubensis clade 2, mating type A1, in Cucumis melo and dual-clade marker development. Theor Appl Genet 2023; 136:91. [PMID: 37009963 DOI: 10.1007/s00122-023-04333-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
This is the first identification of QTLs underlying resistance in Cucumis melo to an isolate of Pseudoperonospora cubensis identified as Clade 2/mating type A1. Pseudoperonospora cubensis, causal organism of cucurbit downy mildew (CDM), causes severe necrosis and defoliation on Cucumis melo (melon). A recombinant inbred line population (N = 169) was screened against an isolate of P. cubensis (Clade 2/mating type A1) in replicated greenhouse and growth chamber experiments. SNPs (n = 5633 bins) identified in the RIL population were used for quantitative trait loci (QTL) mapping. A single major QTL on chromosome 10 (qPcub-10.3-10.4) was consistently associated with resistance across all experiments, while a second major QTL on chromosome 8 (qPcub-8.3) was identified only in greenhouse experiments. These two major QTLs were identified on the same chromosomes (8 and 10) but in different locations as two major QTLs (qPcub-8.2 and qPcub-10.1) previously identified for resistance to P. cubensis Clade 1/mating type A2. Kompetitive allele-specific PCR (KASP) markers were developed for these four major QTLs and validated in the RIL population through QTL mapping. These markers will provide melon breeders a high-throughput genotyping toolkit for development of melon cultivars with broad tolerance to CDM.
Collapse
Affiliation(s)
- Sean M Toporek
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC, 29414, USA.
| | - Sandra E Branham
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC, 29414, USA
| | - Anthony P Keinath
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC, 29414, USA
| | - W Patrick Wechter
- US Vegetable Laboratory, USDA, ARS, 2700 Savannah Highway, Charleston, SC, 29414, USA
| |
Collapse
|
13
|
Qi LL, Talukder ZI, Ma GJ, Seiler GJ. Introgression and targeting of the Pl 37 and Pl 38 genes for downy mildew resistance from wild Helianthus annuus and H. praecox into cultivated sunflower (Helianthus annuus L.). Theor Appl Genet 2023; 136:82. [PMID: 36952051 DOI: 10.1007/s00122-023-04316-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Two new downy mildew resistance genes, Pl37 and Pl38, were introgressed from wild sunflower species into cultivated sunflower and mapped to sunflower chromosomes 4 and 2, respectively Downy mildew (DM), caused by the oomycete pathogen Plasmopara halstedii (Farl.) Berl. & de Toni, is known as the most prevalent disease occurring in global sunflower production areas, especially in North America and Europe. In this study, we report the introgression and molecular mapping of two new DM resistance genes from wild sunflower species, Helianthus annuus and H. praecox, into cultivated sunflower. Two mapping populations were developed from the crosses of HA 89/H. annuus PI 435417 (Pop1) and CMS HA 89/H. praecox PRA-417 (Pop2). The phenotypic evaluation of DM resistance/susceptibility was conducted in the BC1F2-derived BC1F3 populations using P. halstedii race 734. The BC1F2 segregating Pop1 was genotyped using an Optimal GBS AgriSeq™ Panel consisting of 768 mapped SNP markers, while the BC1F2 segregating Pop2 was genotyped using a genotyping-by-sequencing approach. Linkage analysis and subsequent saturation mapping placed the DM resistance gene, designated Pl37, derived from H. annuus PI 435417 in a 1.6 cM genetic interval on sunflower chromosome 4. Pl37 co-segregated with SNP markers SPB0003 and C4_5738736. Similarly, linkage analysis and subsequent saturation mapping placed the DM resistance gene, designated Pl38, derived from H. praecox PRA-417 in a 0.8 cM genetic interval on sunflower chromosome 2. Pl38 co-segregated with seven SNP markers. Multi-pathotype tests revealed that lines with Pl37 or Pl38 are immune to the most prevalent and virulent P. halstedii races tested. Two germplasm lines, HA-DM15 with Pl37 and HA-DM16 with Pl38, were developed for use in sunflower DM-resistance breeding.
Collapse
Affiliation(s)
- L L Qi
- USDA-Agricultural Research Service, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Blvd. N, Fargo, ND, 58102-2765, USA.
| | - Z I Talukder
- USDA-Agricultural Research Service, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Blvd. N, Fargo, ND, 58102-2765, USA
| | - G J Ma
- Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA
- Ball Horticultural Company, 622 Town Road, West Chicago, IL, 60185, USA
| | - G J Seiler
- USDA-Agricultural Research Service, Edward T. Schafer Agricultural Research Center, 1616 Albrecht Blvd. N, Fargo, ND, 58102-2765, USA
| |
Collapse
|
14
|
D'Arcangelo KN, Wallace EC, Miles TD, Quesada-Ocampo LM. Carboxylic Acid Amide but Not Quinone Outside Inhibitor Fungicide Resistance Mutations Show Clade-Specific Occurrence in Pseudoperonospora cubensis Causing Downy Mildew in Commercial and Wild Cucurbits. Phytopathology 2023; 113:80-89. [PMID: 35918851 DOI: 10.1094/phyto-05-22-0166-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Since its reemergence in 2004, Pseudoperonospora cubensis, the causal agent of cucurbit downy mildew (CDM), has experienced significant changes in fungicide sensitivity. Presently, frequent fungicide applications are required to control the disease in cucumber due to the loss of host resistance. Carboxylic acid amides (CAA) and quinone outside inhibitors (QoI) are two fungicide groups used to control foliar diseases in cucurbits, including CDM. Resistance to these fungicides is associated with single nucleotide polymorphism (SNP) mutations. In this study, we used population analyses to determine the occurrence of fungicide resistance mutations to CAA and QoI fungicides in host-adapted clade 1 and clade 2 P. cubensis isolates. Our results revealed that CAA-resistant genotypes occurred more prominently in clade 2 isolates, with more sensitive genotypes observed in clade 1 isolates, while QoI resistance was widespread across isolates from both clades. We also determined that wild cucurbits can serve as reservoirs for P. cubensis isolates containing fungicide resistance alleles. Finally, we report that the G1105W substitution associated with CAA resistance was more prominent within clade 2 P. cubensis isolates while the G1105V resistance substitution and sensitivity genotypes were more prominent in clade 1 isolates. Our findings of clade-specific occurrence of fungicide resistance mutations highlight the importance of understanding the population dynamics of P. cubensis clades by crop and region to design effective fungicide programs and establish accurate baseline sensitivity to active ingredients in P. cubensis populations.
Collapse
Affiliation(s)
- K N D'Arcangelo
- Department of Entomology and Plant Pathology and NC Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27606-7825
| | - E C Wallace
- Department of Entomology and Plant Pathology and NC Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27606-7825
| | - T D Miles
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - L M Quesada-Ocampo
- Department of Entomology and Plant Pathology and NC Plant Sciences Initiative, North Carolina State University, Raleigh, NC 27606-7825
| |
Collapse
|
15
|
Tan J, Wang Y, Dymerski R, Wu Z, Weng Y. Sigma factor binding protein 1 (CsSIB1) is a putative candidate of the major-effect QTL dm5.3 for downy mildew resistance in cucumber (Cucumis sativus). Theor Appl Genet 2022; 135:4197-4215. [PMID: 36094614 DOI: 10.1007/s00122-022-04212-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 09/02/2022] [Indexed: 06/15/2023]
Abstract
The dm5.3 major-effect QTL in cucumber encodes a homolog of Arabidopsis sigma factor binding protein 1 (CsSIB1). CsSIB1 positively regulates defense responses against downy mildew in cucumber through the salicylic acid (SA) biosynthesis/signaling pathway. Downy mildew (DM) caused by the oomycete pathogen Pseudoperonospora cubensis is an important disease of cucumber and other cucurbits. Our knowledge on molecular mechanisms of DM resistance is still limited. In this study, we reported identification and functional characterization of the candidate gene for the major-effect QTL, dm5.3 for DM resistance originated from PI 197088. The dm5.3 QTL was Modelized through marker-assisted development of near isogenic lines (NILs). NIL-derived segregating populations were used for fine mapping which narrowed the dm5.3 locus down to a 144 kb region. Based on multiple lines of evidence, we show that CsSIB1 (CsGy5G027140) that encodes the VQ motif-containing sigma factor binding protein 1 as the most likely candidate for dm5.3. Local association analysis identified a haplotype consisting of 7 SNPs inside the coding and promoter region of CsSIB1 that was associated with DM resistance. Expression of CsSIB1 was up-regulated with P. cubensis infection. Transcriptome profiling of NILs in response to P. cubensis inoculation revealed key players and associated gene networks in which increased expression of CsSIB1 antagonistically promoted salicylic acid (SA) but suppressed jasmonic acid (JA) biosynthesis/signaling pathways. Our work provides novel insights into the function of CsSIB1/dm5.3 as a disease resistance (R) gene. The roles of sigma factor binding protein genes in pathogen defense in cucumber were also discussed.
Collapse
Affiliation(s)
- Junyi Tan
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
| | - Yuhui Wang
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
| | - Ronald Dymerski
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
| | - Zhiming Wu
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
- Institute of Cash Crops, Hebei Academy of Agriculture & Forestry Sciences, Shijiazhuang, 050051, Hebei, China
| | - Yiqun Weng
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA.
- USDA-ARS Vegetable Crops Research Unit, Madison, WI, 53706, USA.
| |
Collapse
|
16
|
Gao S, Lu T, She H, Xu Z, Zhang H, Liu Z, Qian W. Fine Mapping and Identification of a Candidate Gene of Downy Mildew Resistance, RPF2, in Spinach ( Spinacia oleracea L.). Int J Mol Sci 2022; 23:ijms232314872. [PMID: 36499197 PMCID: PMC9737595 DOI: 10.3390/ijms232314872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/17/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Downy mildew is a major threat to the economic value of spinach. The most effective approach to managing spinach downy mildew is breeding cultivars with resistance genes. The resistance allele RPF2 is effective against races 1-10 and 15 of Peronospora farinosa f. sp. Spinaciae (P. effusa) and is widely used as a resistance gene. However, the gene and the linked marker of RPF2 remain unclear, which limit its utilization. Herein, we located the RPF2 gene in a 0.61 Mb region using a BC1 population derived from Sp39 (rr) and Sp62 (RR) cultivars via kompetitive allele specific PCR (KASP) markers. Within this region, only one R gene, Spo12821, was identified based on annotation information. The amino acid sequence analysis showed that there were large differences in the length of the LRR domain between the parents. Additionally, a molecular marker, RPF2-IN12821, was developed based on the sequence variation in the Spo12821, and the evaluation in the BC1 population produced a 100% match with resistance/susceptibility. The finding of the study could be valuable for improving our understanding of the genetic basis of resistance against the downy mildew pathogen and breeding resistance lines in the future.
Collapse
|
17
|
Higgins DS, Miles TD, Byrne JM, Hausbeck MK. Optimizing Molecular Detection for the Hop Downy Mildew Pathogen Pseudoperonospora humuli in Plant Tissue. Phytopathology 2022; 112:2426-2439. [PMID: 35722890 DOI: 10.1094/phyto-01-22-0013-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Downy mildew-free hop plantlets and rhizomes are essential to limit the introduction of this destructive pathogen, Pseudoperonospora humuli, into hopyards. The objective of this research was to determine which DNA-based diagnostic tools are optimal for P. humuli detection in plant tissue. Quantitative real-time PCR (qPCR) assays with TaqMan probes for nuclear (c125015.3e1) and mitochondrial (orf359) DNA loci were developed and tested side by side. A recombinase polymerase amplification (RPA) assay was designed based on the orf359 DNA locus. The mitochondrial qPCR assay had a 10-fold lower limit of detection (100 fg of genomic DNA) and was 60% more effective in detecting P. humuli in asymptomatic stems than the nuclear-based assay. Both qPCR assays had linear standard curves (R2 > 0.99) but lacked the quantitative precision to differentiate leaf infections beyond 1 day postinoculation. A wide range of Cq values (≥4.9) in standardized tests was observed among isolates, suggesting that the number of mitochondria and nuclear DNA targets can vary. The absence of P. humuli DNA in symptomatic rhizomes was explained, in part, by the detection of Phytophthora DNA. However, the Phytophthora-specific atp9-nad9 assay cross-reacted with P. humuli, leading to false positive amplification. Sensitivity in the RPA assay was reduced by crude plant DNA extract. Improvements to the objectivity of calling positive amplifications and determining the onset of amplification from RPA fluorescence data were realized by applying the first and second derivatives, respectively. The orf359 qPCR assay is specific and sensitive, making it well suited for P. humuli diagnostics in plant tissue.
Collapse
Affiliation(s)
- Douglas S Higgins
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Timothy D Miles
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Jan M Byrne
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Mary K Hausbeck
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| |
Collapse
|
18
|
Lacotte V, Peignier S, Raynal M, Demeaux I, Delmotte F, da Silva P. Spatial-Spectral Analysis of Hyperspectral Images Reveals Early Detection of Downy Mildew on Grapevine Leaves. Int J Mol Sci 2022; 23:ijms231710012. [PMID: 36077411 PMCID: PMC9456054 DOI: 10.3390/ijms231710012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/10/2022] [Accepted: 08/25/2022] [Indexed: 11/30/2022] Open
Abstract
Downy mildew is a highly destructive disease of grapevine. Currently, monitoring for its symptoms is time-consuming and requires specialist staff. Therefore, an automated non-destructive method to detect the pathogen before the visible symptoms appear would be beneficial for early targeted treatments. The aim of this study was to detect the disease early in a controlled environment, and to monitor the disease severity evolution in time and space. We used a hyperspectral image database following the development from 0 to 9 days post inoculation (dpi) of three strains of Plasmopara viticola inoculated on grapevine leaves and developed an automatic detection tool based on a Support Vector Machine (SVM) classifier. The SVM obtained promising validation average accuracy scores of 0.96, a test accuracy score of 0.99, and it did not output false positives on the control leaves and detected downy mildew at 2 dpi, 2 days before the clear onset of visual symptoms at 4 dpi. Moreover, the disease area detected over time was higher than that when visually assessed, providing a better evaluation of disease severity. To our knowledge, this is the first study using hyperspectral imaging to automatically detect and show the spatial distribution of downy mildew on grapevine leaves early over time.
Collapse
Affiliation(s)
- Virginie Lacotte
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France
| | - Sergio Peignier
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France
- Correspondence: (S.P.); (P.d.S.)
| | - Marc Raynal
- IFV, UMT Seven, F-33140 Villenave d’Ornon, France
| | - Isabelle Demeaux
- SAVE, INRAE, Bordeaux Sciences Agro, Univ. Bordeaux, F-33140 Villenave d’Ornon, France
| | - François Delmotte
- SAVE, INRAE, Bordeaux Sciences Agro, Univ. Bordeaux, F-33140 Villenave d’Ornon, France
| | - Pedro da Silva
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France
- Correspondence: (S.P.); (P.d.S.)
| |
Collapse
|
19
|
Kikway I, Keinath AP, Ojiambo PS. Field Occurrence and Overwintering of Oospores of Pseudoperonospora cubensis in the Southeastern United States. Phytopathology 2022; 112:1946-1955. [PMID: 35384722 DOI: 10.1094/phyto-11-21-0467-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In the United States, the cucurbit downy mildew pathogen, Pseudoperonospora cubensis, has been shown to form oospores under laboratory conditions, but there are no reports on the formation of oospores in naturally infected cucurbit plants in the field. This study investigated the occurrence of oospores in naturally infected leaves from cucurbit fields in North Carolina and South Carolina from 2018 to 2020. Oospore viability and survival was also determined outdoors during the winter in North Carolina during this study period using soil containing leaves infested with oospores. About 5% of 1,658 naturally infected cucumber and cantaloupe leaves sampled during the study had oospores, with a mean density of 585 oospores per cm2 of infected leaf tissue. Absolute oospore viability, as assessed using the plasmolysis method, declined linearly (slope = -0.27; P < 0.0001) over the 6-month exposure period from 67.8% in November to 19.3% in May. Other variables being equal, the decrease in oospore viability was significantly affected by soil temperature (b = -0.03 to -0.05; P < 0.0001) and number of rainy days (b = 21.6 to 40.46; P < 0.05), while the effects of soil moisture on oospore viability were less clear. About 20% of the oospores exposed to outdoor conditions at the end the study period were putatively viable and deemed potentially infective. However, these putatively viable oospores failed to germinate or initiate disease when inoculated onto cucumber or cantaloupe leaves. These results indicate that oospores might require some unrecognized stimuli or physiological factors to initiate germination and infection. Nonetheless, viability of oospores at the end of the winter season suggests that once exposed to the right conditions that stimulate germination, these oospores could potentially serve as a primary inoculum source in the southeastern United States where winter temperatures are cold enough to kill cucurbits plants.
Collapse
Affiliation(s)
- Isaack Kikway
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Anthony P Keinath
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414
| | - Peter S Ojiambo
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| |
Collapse
|
20
|
Ma G, Song Q, Li X, Qi L. Genetic Insight into Disease Resistance Gene Clusters by Using Sequencing-Based Fine Mapping in Sunflower (Helianthus annuus L.). Int J Mol Sci 2022; 23:ijms23179516. [PMID: 36076914 PMCID: PMC9455867 DOI: 10.3390/ijms23179516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/04/2022] [Accepted: 08/19/2022] [Indexed: 11/16/2022] Open
Abstract
Rust and downy mildew (DM) are two important sunflower diseases that lead to significant yield losses globally. The use of resistant hybrids to control rust and DM in sunflower has a long history. The rust resistance genes, R13a and R16, were previously mapped to a 3.4 Mb region at the lower end of sunflower chromosome 13, while the DM resistance gene, Pl33, was previously mapped to a 4.2 Mb region located at the upper end of chromosome 4. High-resolution fine mapping was conducted using whole genome sequencing of HA-R6 (R13a) and TX16R (R16 and Pl33) and large segregated populations. R13a and R16 were fine mapped to a 0.48 cM region in chromosome 13 corresponding to a 790 kb physical interval on the XRQr1.0 genome assembly. Four disease defense-related genes with nucleotide-binding leucine-rich repeat (NLR) motifs were found in this region from XRQr1.0 gene annotation as candidate genes for R13a and R16. Pl33 was fine mapped to a 0.04 cM region in chromosome 4 corresponding to a 63 kb physical interval. One NLR gene, HanXRQChr04g0095641, was predicted as the candidate gene for Pl33. The diagnostic SNP markers developed for each gene in the current study will facilitate marker-assisted selections of resistance genes in sunflower breeding programs.
Collapse
Affiliation(s)
- Guojia Ma
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102-6050, USA
| | - Qijian Song
- Soybean Genomics and Improvement Laboratory, USDA-Agricultural Research Service, Beltsville, MD 20705-2350, USA
| | - Xuehui Li
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102-6050, USA
| | - Lili Qi
- USDA-Agricultural Research Service, Edward T. Schafer Agricultural Research Center, Fargo, ND 58102-2765, USA
- Correspondence:
| |
Collapse
|
21
|
Toporek SM, Keinath AP. Efficacy of Fungicides Used to Manage Downy Mildew in Cucumber Assessed with Multiple Meta-Analysis Techniques. Phytopathology 2022; 112:1651-1658. [PMID: 35263164 DOI: 10.1094/phyto-10-21-0432-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A nationwide, quantitative synthesis of fungicide efficacy data on management of cucurbit downy mildew (CDM) caused by Pseudoperonospora cubensis is needed to broadly evaluate fungicide performance. Three-level meta-analysis, three-level meta-regression, and network meta-analyses were conducted on data from 46 cucumber (Cucumis sativus) CDM fungicide efficacy studies conducted in the eastern United States retrieved from Plant Disease Management Reports published between 2009 and 2018. Three response variables were examined in each analysis: disease severity, marketable yield, and total yield, from which percent disease control and percent yield return compared with nontreated controls was calculated. Moderator variables used in the three-level meta-analysis or three-level meta-regression included year, disease pressure, number of fungicide applications, and slicing or pickling cucumbers. In the network meta-analysis, fungicides were grouped by common combinations of Fungicide Resistance Action Committee Codes and modes of action. Overall, fungicides significantly (P < 0.001) reduced disease severity and increased marketable and total yields, resulting in a mean 54.0% disease control and 61.9% marketable and 73.3% total yield return. Subgroup differences were observed for several fungicide applications, control plot disease severity, and cucumber type for marketable yield. Based on the meta-regression analysis for disease severity by year, fungicide efficacy has been decreasing from 2009 to 2018, potentially indicating broad development of fungicide resistance over time. Treatments containing quinone inside inhibitors, pyridinylmethyl-benzamides, and protectants and treatments containing oxysterol binding protein inhibitors and protectants most effectively reduced disease severity. The most effective fungicide combinations for disease control did not always result in the highest yield return.
Collapse
Affiliation(s)
- Sean M Toporek
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414
| | - Anthony P Keinath
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414
| |
Collapse
|
22
|
Marie Juraschek L, Matera C, Steiner U, Oerke EC. Pathogenesis of Plasmopara viticola Depending on Resistance Mediated by Rpv3_1, and Rpv10 and Rpv3_3, and by the Vitality of Leaf Tissue. Phytopathology 2022; 112:1486-1499. [PMID: 35681263 DOI: 10.1094/phyto-10-21-0415-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Grapevine cultivars vary in their resistance to Plasmopara viticola, causal agent of downy mildew. Genes from various Vitis species confer pathogen resistance (Rpv), resulting in reduced compatibility of the host-pathogen interaction and partial disease resistance that may become apparent at different stages of pathogenesis. This study describes the pathogenesis of P. viticola on the partially resistant cultivars Regent (Rpv3-1) and Solaris (Rpv3-3, Rpv10) as compared with the susceptible cultivar Mueller-Thurgau using various microscopic techniques, visual disease rating as well as qPCR. Host plant resistance had no effect on the initial steps of pathogenesis outside the host plant cells (zoospore attachment, formation of substomatal vesicle) and became detectable only after the formation of primary haustoria. The restricted compatibility resulted in reductions in haustorium size and in the number of secondary haustoria and was associated with callose depositions around haustoria and stomatal guard cells, collapsed mesophyll cells (hypersensitive reaction), and additional production of an amorphous substance in the intercellular space of cultivar Solaris. Resistance mechanisms reduced the efficiency of P. viticola haustoria and largely restricted tissue colonization to the spongy parenchyma; resistance of cultivar Solaris having thicker leaves was more effective than that of cultivar Regent. Despite of the effects of resistance genes, P. viticola was able to complete its life cycle by forming sporangiophores with sporangia through the stomata on both resistant cultivars indicating partial resistance. Differences in the pathogenesis on detached and attached grapevine leaves highlighted the impact of host tissue vitality on both resistance and susceptibility to the biotrophic pathogen.
Collapse
Affiliation(s)
- Lena Marie Juraschek
- Institute of Crop Science and Resource Conservation-Plant Pathology, Rheinische Friedrich-Wilhelms-Universitaet Bonn, 53115 Bonn, Germany
| | - Christiane Matera
- Institute of Crop Science and Resource Conservation-Plant Pathology, Rheinische Friedrich-Wilhelms-Universitaet Bonn, 53115 Bonn, Germany
| | - Ulrike Steiner
- Institute of Crop Science and Resource Conservation-Plant Pathology, Rheinische Friedrich-Wilhelms-Universitaet Bonn, 53115 Bonn, Germany
| | - Erich-Christian Oerke
- Institute of Crop Science and Resource Conservation-Plant Pathology, Rheinische Friedrich-Wilhelms-Universitaet Bonn, 53115 Bonn, Germany
| |
Collapse
|
23
|
El-Sharkawy HHA, Rashad YM, El-Kenawy MA, Galilah DA. Magnesium carbonate elicits defense-related genes in King Ruby grapevines against downy mildew and improves its growth, yield, and berries quality. Pestic Biochem Physiol 2022; 184:105075. [PMID: 35715030 DOI: 10.1016/j.pestbp.2022.105075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/25/2022] [Accepted: 03/05/2022] [Indexed: 06/15/2023]
Abstract
Downy mildew, caused by Plasmopara viticola (Berk. and M. A. Curtis) Berl. and De Toni, is a serious disease of grapevines in general and King Ruby seedless cultivar in particular, affecting their growth and yield. Magnesium carbonate (MgCO3) is an antitranspirant, which induces stomatal closing and enhances plant growth and physiology. In this study, effect of foliar application of MgCO3 at 1 and 3% on plant resistance, growth, yield and physiology of grapevines (cv. King Ruby seedless) infected with downy mildew was investigated under field conditions. The obtained results showed that foliar application of MgCO3 at 3% led to upregulation of the transcription factor JERF3 (9.6-fold), and the defense-related genes GLU (6.3-fold), POD (8.7-fold), PR1 (9.6-fold), and CHI II (8.6-fold). In addition, this treatment led to a reduction in the disease severity (78%), and an increment in the yield per grapevine (20%). Furthermore, biochemical properties of berries, total contents of the photosynthetic pigments, phenolic compounds, and activities of the antioxidant enzymes peroxidase and polyphenol oxidase also enhanced. In contrast, lipid peroxidation, and H2O2 content in grapevines leaves reduced in response to MgCO3 spraying. Light microscope observations revealed that average number of closed stomata increased and the average stomatal pore area decreased in grapevines leaves as a result to MgCO3 spraying. Based on these results, we can conclude that spraying with MgCO3 at 3% has effective roles in inducing the plant resistance against downy mildew, and improving the growth and yield of grapevines.
Collapse
Affiliation(s)
- Hany H A El-Sharkawy
- Department of Mycology Research and Plant Disease Survey, Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt
| | - Younes M Rashad
- Plant Protection and Biomolecular Diagnosis Department, Arid Lands Cultivation Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City 21934, Egypt.
| | - Mosaad A El-Kenawy
- Viticulture Department, Horticulture Research Institute, Agricultural Research Center, Giza, Egypt
| | - Doaa A Galilah
- Mansoura University, Faculty of Science, Botany Department, Mansoura, Egypt
| |
Collapse
|
24
|
Giudice G, Moffa L, Niero M, Duso C, Sandrini M, Vazzoler LF, Luison M, Pasini E, Chitarra W, Nerva L. Novel sustainable strategies to control Plasmopara viticola in grapevine unveil new insights on priming responses and arthropods ecology. Pest Manag Sci 2022; 78:2342-2356. [PMID: 35246907 DOI: 10.1002/ps.6860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/26/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Reduction of fungicide consumption in agriculture is globally recognized as a priority. Government authorities are fostering research to achieve a reduction of risks associated with conventional pesticides and promoting the development of sustainable alternatives. To address these issues, in the present study, alternative protocols for the control of downy mildew infection in grapevine were compared to the standard protocol. In the first protocol, only resistance inducers were used, comprising a single formulation with Acibenzolar S-methyl, laminarin and disodium-phosphonate. The second and third protocols followed the standard protocol but substituted phosphonates with phosphorus pentoxide and Ecklonia maxima extract. RESULTS The results showed that at veraison downy mildew incidence and severity in all tested protocols were significantly reduced compared to nontreated controls on both canopy and bunches. Expression analysis of key genes involved in plant stress response, indicated that the two protocols for phosphites substitution induced a remodulation of salicylic acid (SA) and jasmonic acid (JA), with positive impact on yields. Analysis of the first protocol revealed that the primed state induced a short delay in bunch ripening, with a shift of carbohydrate metabolism to boost the plant defences, involving an upregulation of defence related-gene, SAR response and a decreased ROS detoxification. Additionally, analysis on the arthropods populations, in parallel with the positive results achieved using alternatives to conventional fungicides, were enriched by those showing the potential of naturally occurring predators of spider mites. CONCLUSION This study provides practical solutions to reduce the environmental impact of treatments for the control downy mildew in viticulture. © 2022 Society of Chemical Industry.
Collapse
Affiliation(s)
- Gaetano Giudice
- Council for Agricultural Research and Economics, Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
- Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy (DiSAA), University of Milano, Milan, Italy
| | - Loredana Moffa
- Council for Agricultural Research and Economics, Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Marina Niero
- Council for Agricultural Research and Economics, Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
| | - Carlo Duso
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
| | - Marco Sandrini
- Council for Agricultural Research and Economics, Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | | | | | | | - Walter Chitarra
- Council for Agricultural Research and Economics, Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
- Institute for Sustainable Plant Protection, CNR, Torino, Italy
| | - Luca Nerva
- Council for Agricultural Research and Economics, Research Centre for Viticulture and Enology CREA-VE, Conegliano, Italy
- Institute for Sustainable Plant Protection, CNR, Torino, Italy
| |
Collapse
|
25
|
Simko I, Peng H, Sthapit Kandel J, Zhao R. Genome-wide association mapping reveals genomic regions frequently associated with lettuce field resistance to downy mildew. Theor Appl Genet 2022; 135:2009-2024. [PMID: 35419653 DOI: 10.1007/s00122-022-04090-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
KEY MESSAGE GWAS identified 63 QTLs for resistance to downy mildew. Though QTLs were distributed across all chromosomes, the genomic regions frequently associated with resistance were located on chromosomes 4 and 5. Lettuce downy mildew is one of the most economically important diseases of cultivated lettuce worldwide. We have applied the genome-wide association mapping (GWAS) approach to detect QTLs for field resistance to downy mildew in the panel of 496 accessions tested in 21 field experiments. The analysis identified 131 significant marker-trait associations that could be grouped into 63 QTLs. At least 51 QTLs were novel, while remaining 12 QTLs overlapped with previously described QTLs for lettuce field resistance to downy mildew. Unlike race-specific, dominant Dm genes that mostly cluster on three out of nine lettuce chromosomes, QTLs (qDMR loci) for polygenic resistance are randomly distributed across all nine chromosomes. The genomic regions frequently associated with lettuce field resistance to downy mildew are located on chromosomes 4 and 5 and could be used for detailed study of the mechanism of polygenic resistance. The most resistant accessions identified in the current study (cvs. Auburn, Grand Rapids, Romabella, PI 226514, and PI 249536) are being incorporated into our breeding program. Markers closely linked to the resistance QTLs could be potentially used for marker-assisted selection, or in combination with other markers in the genome, for a combined genomic and marker-assisted selection. Up to date this is the most comprehensive study of QTLs for field resistance to downy mildew and the first study that uses GWAS for mapping disease resistance loci in lettuce.
Collapse
Affiliation(s)
- Ivan Simko
- U.S. Department of Agriculture, Agricultural Research Service, Crop Improvement and Protection Research Unit, Salinas, CA, 93905, USA.
| | - Hui Peng
- The Genome Center and Department of Plant Pathology, University of California, Davis, CA, 95616, USA
| | - Jinita Sthapit Kandel
- U.S. Department of Agriculture, Agricultural Research Service, Crop Improvement and Protection Research Unit, Salinas, CA, 93905, USA
- Thad Cochran Southern Horticultural Laboratory, U.S. Department of Agriculture, Agricultural Research Service, Poplarville, MS, 39470, USA
| | - Rebecca Zhao
- U.S. Department of Agriculture, Agricultural Research Service, Crop Improvement and Protection Research Unit, Salinas, CA, 93905, USA
| |
Collapse
|
26
|
Shirley AM, Vallad GE, Dufault N, Raid R, Quesada-Ocampo L. Duration of Downy Mildew Control Achieved with Fungicides on Cucumber Under Florida Field Conditions. Plant Dis 2022; 106:1167-1174. [PMID: 34546773 DOI: 10.1094/pdis-03-21-0507-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Cucurbit production in Florida is impacted by downy mildew on a yearly basis. Cucurbit downy mildew (CDM), caused by Pseudoperonospora cubensis, is one of the most devastating cucurbit diseases and can lead to complete yield loss. Nearly continuous production of cucurbits occurs temporally throughout Florida, which puts extensive pressure on the pathogen population to select for individuals that are resistant to fungicides in use labeled for CDM. Loss of efficacy as a result of fungicide resistance developing is becoming a major concern for Florida cucurbit growers who rely on these products to manage CDM. This study was established to evaluate the field activity of 11 utilized fungicides by determining their duration of activity when applied at various intervals for the management of CDM in cucumber under Florida field conditions. By comparing levels of percent CDM control and area under the disease progress curve values, the fungicide's duration of field activity was established. Field activities were <1 week for dimethomorph and fluopicolide; 1 week for cymoxanil; 1 to 2 weeks for chlorothalonil and mancozeb; 2 weeks for ethaboxam; 1 to 3 weeks for propamocarb, cyazofamid, and ametoctradin + dimethomorph; and 2 to 4 weeks for oxathiapiprolin and fluazinam. Knowledge of duration of field activity can potentially improve the development of CDM management programs and slow the resistance selection.
Collapse
Affiliation(s)
- Andrew M Shirley
- University of Florida, Department of Plant Pathology, Gulf Coast Research and Education Center, Wimauma, FL 33598
| | - Gary E Vallad
- University of Florida, Department of Plant Pathology, Gulf Coast Research and Education Center, Wimauma, FL 33598
| | - Nicholas Dufault
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611
| | - Richard Raid
- University of Florida, Department of Plant Pathology, Everglades Research and Education Center, Belle Glade, FL 33430
| | - Lina Quesada-Ocampo
- North Carolina State University, Department of Entomology and Plant Pathology, Raleigh, NC 27695
| |
Collapse
|
27
|
Kikway I, Keinath AP, Ojiambo PS. Temporal Dynamics and Severity of Cucurbit Downy Mildew Epidemics as Affected by Chemical Control and Cucurbit Host Type. Plant Dis 2022; 106:1009-1019. [PMID: 34735276 DOI: 10.1094/pdis-09-21-1992-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Cucurbit downy mildew caused by the oomycete Pseudoperonospora cubensis is an important disease that affects members of Cucurbitaceae family globally. However, temporal dynamics of the disease have not been characterized at the field scale to understand how control strategies influence disease epidemics. Disease severity was assessed visually on cucumber and summer squash treated with weekly alternation of chlorothalonil with cymoxanil, fluopicolide, or propamocarb during the 2018 spring season and 2019 and 2020 fall seasons in North Carolina and the 2018 and 2020 fall seasons in South Carolina. Disease onset was observed around mid-June during the spring season and early September during the fall season, followed by a rapid increase in severity until mid-July in the spring season and late September or mid-October in the fall season, typical of polycyclic epidemics. The Gompertz, logistic, and monomolecular growth models were fitted to disease severity using linear regression and parameter estimates to compare the effects of fungicide treatment and cucurbit host type on disease progress. The Gompertz and logistic models were more appropriate than the monomolecular model in describing temporal dynamics of cucurbit downy mildew, with the Gompertz model providing the best description for 34 of the 44 epidemics examined. Fungicide treatment and host type significantly (P < 0.0001) affected the standardized area under disease progress curve (sAUDPC), final disease severity (Final DS), and weighted mean absolute rates of disease progress (ρ), with these variables, in most cases, being significantly (P < 0.05) lower in fungicide-treated plots than in untreated control plots. Except in a few cases, sAUDPC, Final DS, and ρ were lower in cases where chlorothalonil was alternated with fluopicolide or propamocarb than in cases where chlorothalonil was alternated with cymoxanil or when chlorothalonil was applied alone. These results characterized the temporal progress of cucurbit downy mildew and provided an improved understanding of the dynamics of the disease at the field level. Parameters of disease progress obtained from this study could serve as inputs in simulation studies to assess the efficacy of fungicide alternation in managing fungicide resistance in this pathosystem.
Collapse
Affiliation(s)
- Isaack Kikway
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Anthony P Keinath
- Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414
| | - Peter S Ojiambo
- Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| |
Collapse
|
28
|
Van der Heyden H, Dutilleul P, Duceppe M, Bilodeau GJ, Charron J, Carisse O. Genotyping by sequencing suggests overwintering of Peronospora destructor in southwestern Québec, Canada. Mol Plant Pathol 2022; 23:339-354. [PMID: 34921486 PMCID: PMC8828460 DOI: 10.1111/mpp.13158] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 05/19/2023]
Abstract
Several Peronospora species are carried by wind over short and long distances, from warmer climates where they survive on living plants to cooler climates. In eastern Canada, this annual flow of sporangia was thought to be the main source of Peronospora destructor responsible for onion downy mildew. However, the results of a recent study showed that the increasing frequency of onion downy mildew epidemics in eastern Canada is associated with warmer autumns, milder winters, and previous year disease severity, suggesting overwintering of the inoculum in an area where the pathogen is not known to be endogenous. In this study, genotyping by sequencing was used to investigate the population structure of P. destructor at the landscape scale. The study focused on a particular region of southwestern Québec-Les Jardins de Napierville-to determine if the populations were clonal and regionally differentiated. The data were characterized by a high level of linkage disequilibrium, characteristic of clonal organisms. Consequently, the null hypothesis of random mating was rejected when tested on predefined or nonpredefined populations, indicating that linkage disequilibrium was not a function of population structure and suggesting a mixed reproduction mode. Discriminant analysis of principal components performed with predefined population assignment allowed grouping P. destructor isolates by geographical regions, while analysis of molecular variance confirmed that this genetic differentiation was significant at the regional level. Without using a priori population assignment, isolates were clustered into four genetic clusters. These results represent a baseline estimate of the genetic diversity and population structure of P. destructor.
Collapse
Affiliation(s)
- Hervé Van der Heyden
- Cie de Recherche PhytodataSherringtonQuébecCanada
- Department of Plant ScienceMcGill UniversityMontrealQuébecCanada
| | - Pierre Dutilleul
- Department of Plant ScienceMcGill UniversityMontrealQuébecCanada
| | | | | | | | - Odile Carisse
- Agriculture and Agri‐Food CanadaSt‐Jean‐sur‐RichelieuQuébecCanada
| |
Collapse
|
29
|
Nolen H, Smith C, Davis TM, Poleatewich A. Evaluation of Disease Severity and Molecular Relationships Between Peronospora variabilis Isolates on Chenopodium Species in New Hampshire. Plant Dis 2022; 106:564-571. [PMID: 34633235 DOI: 10.1094/pdis-06-21-1150-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Quinoa is a potential new crop for New England; however, its susceptibility to downy mildew, caused by Peronospora variabilis, is a key obstacle for cultivation. The objectives of this study were to evaluate differential resistance within the Chenopodium genus, identify novel sources of resistance for use in future genetic studies or breeding programs, and investigate phylogenetic relationships of P. variabilis isolates from different Chenopodium hosts. The long-term goal of this research is to develop a resistant variety of quinoa to be grown in New England. Field trials conducted at the University of New Hampshire evaluated downy mildew disease severity on 10 Chenopodium accessions representing four species. Disease severity for each treatment was compared and significant differences in disease severity were observed between accessions. C. berlandieri var. macrocalycium ecotypes collected from Rye Beach, New Hampshire and Appledore Island, Maine exhibited the lowest disease severity over the growing season. P. variabilis was isolated from each accession, and COX2 sequences were compared. Phylogenetic analyses suggest no effect of host species on P. variabilis sequence similarity; however, isolates are shown to cluster by geographic location. This research provides the first step in identifying potential New England native sources of resistance to downy mildew within the genus Chenopodium and provides preliminary information needed to further investigate resistance at the genomic level in Chenopodium spp.
Collapse
Affiliation(s)
- Haley Nolen
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH 03824
| | - Cheryl Smith
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH 03824
| | - Thomas M Davis
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH 03824
| | - Anissa Poleatewich
- Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH 03824
| |
Collapse
|
30
|
Pirrello C, Malacarne G, Moretto M, Lenzi L, Perazzolli M, Zeilmaker T, Van den Ackerveken G, Pilati S, Moser C, Giacomelli L. Grapevine DMR6-1 Is a Candidate Gene for Susceptibility to Downy mildew. Biomolecules 2022; 12:biom12020182. [PMID: 35204683 PMCID: PMC8961545 DOI: 10.3390/biom12020182] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/16/2022] Open
Abstract
Grapevine (Vitis vinifera) is a valuable crop in Europe for both economical and cultural reasons, but highly susceptible to Downy mildew (DM). The generation of resistant vines is of critical importance for a sustainable viticulture and can be achieved either by introgression of resistance genes in susceptible varieties or by mutation of Susceptibility (S) genes, e.g., by gene editing. This second approach offers several advantages: it maintains the genetic identity of cultivars otherwise disrupted by crossing and generally results in a broad-spectrum and durable resistance, but it is hindered by the poor knowledge about S genes in grapevines. Candidate S genes are Downy mildew Resistance 6 (DMR6) and DMR6-Like Oxygenases (DLOs), whose mutations confer resistance to DM in Arabidopsis. In this work, we show that grapevine VviDMR6-1 complements the Arabidopsis dmr6-1 resistant mutant. We studied the expression of grapevine VviDMR6 and VviDLO genes in different organs and in response to the DM causative agent Plasmopara viticola. Through an automated evaluation of causal relationships among genes, we show that VviDMR6-1, VviDMR6-2, and VviDLO1 group into different co-regulatory networks, suggesting distinct functions, and that mostly VviDMR6-1 is connected with pathogenesis-responsive genes. Therefore, VviDMR6-1 represents a good candidate to produce resistant cultivars with a gene-editing approach.
Collapse
Affiliation(s)
- Carlotta Pirrello
- Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all’Adige, Italy; (C.P.); (G.M.); (M.M.); (L.L.); (M.P.); (S.P.); (C.M.)
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Via delle Scienze 206, 33100 Udine, Italy
| | - Giulia Malacarne
- Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all’Adige, Italy; (C.P.); (G.M.); (M.M.); (L.L.); (M.P.); (S.P.); (C.M.)
| | - Marco Moretto
- Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all’Adige, Italy; (C.P.); (G.M.); (M.M.); (L.L.); (M.P.); (S.P.); (C.M.)
| | - Luisa Lenzi
- Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all’Adige, Italy; (C.P.); (G.M.); (M.M.); (L.L.); (M.P.); (S.P.); (C.M.)
| | - Michele Perazzolli
- Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all’Adige, Italy; (C.P.); (G.M.); (M.M.); (L.L.); (M.P.); (S.P.); (C.M.)
- Center Agriculture Food Environment (C3A), University of Trento, Via E. Mach 1, 38098 San Michele all’Adige, Italy
| | - Tieme Zeilmaker
- SciENZA Biotechnologies B.V., Sciencepark 904, 1098 XH Amsterdam, The Netherlands;
| | - Guido Van den Ackerveken
- Plant-Microbe Interactions, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands;
| | - Stefania Pilati
- Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all’Adige, Italy; (C.P.); (G.M.); (M.M.); (L.L.); (M.P.); (S.P.); (C.M.)
| | - Claudio Moser
- Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all’Adige, Italy; (C.P.); (G.M.); (M.M.); (L.L.); (M.P.); (S.P.); (C.M.)
| | - Lisa Giacomelli
- Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all’Adige, Italy; (C.P.); (G.M.); (M.M.); (L.L.); (M.P.); (S.P.); (C.M.)
- Correspondence:
| |
Collapse
|
31
|
Ray T, Pandey A, Pandey SS, Singh S, Shanker K, Kalra A. Molecular insights into enhanced resistance of Papaver somniferum against downy mildew by application of endophyte bacteria Microbacterium sp. SMR1. Physiol Plant 2021; 173:1862-1881. [PMID: 34407205 DOI: 10.1111/ppl.13528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/30/2021] [Accepted: 08/16/2021] [Indexed: 06/13/2023]
Abstract
Downy mildew is one of the most serious diseases of Papaver somniferum. Endophytes isolated from different parts of P. somniferum were screened for their ability to enhance resistance against downy mildew caused by the obligate biotrophic oomycete Peronospora meconopsidis. Two endophytes (SMR1 and SMR2) reduced the downy mildew on three P. somniferum genotypes (Sampada, J-16, and I-14). SMR1 (Microbacterium sp.) also enhanced the resistance of P. somniferum against downy mildew under field conditions. The biochemical markers of plant susceptibility under biotic stresses (proline and malondialdehyde) were found to be reduced in P. somniferum upon SMR1 treatment. To understand the mechanisms underlying the enhanced resistance to downy mildew in SMR1 endophyte-treated P. somniferum genotype J-16, we compared the expression profiles using the next-generation RNA sequencing approach between P. somniferum pretreated with SMR1 and untreated endophyte-free control plants following exposure to downy mildew pathogen. Comparative transcriptome analysis revealed differential expression of transcripts belonging to broad classes of signal transduction, protein modification, disease/defense proteins, transcription factors, and phytohormones in SMR1-primed P. somniferum after infection with downy mildew pathogen. Furthermore, enhanced salicylic acid content was observed in SMR1-primed P. somniferum after exposure to downy mildew pathogen. This study sheds light on molecular mechanisms underlying enhanced resistance to downy mildew in SMR1-primed P. somniferum. Finally, we propose that the SA-dependent defense pathway, the hallmark of systemic acquired resistance, is activated in SMR1-primed P. somniferum, triggering the endophyte-induced resistance.
Collapse
Affiliation(s)
- Tania Ray
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Alok Pandey
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Shiv S Pandey
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Sucheta Singh
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Karuna Shanker
- Analytical Chemistry Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Alok Kalra
- Microbial Technology Department, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| |
Collapse
|
32
|
Crandall SG, Ramon ML, Burkhardt AK, Bello Rodriguez JC, Adair N, Gent DH, Hausbeck MK, Quesada-Ocampo LM, Martin FN. A Multiplex TaqMan qPCR Assay for Detection and Quantification of Clade 1 and Clade 2 Isolates of Pseudoperonospora cubensis and Pseudoperonospora humuli. Plant Dis 2021; 105:3154-3161. [PMID: 33591831 DOI: 10.1094/pdis-11-20-2339-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The ability to detect and quantify aerially dispersed plant pathogens is essential for developing effective disease control measures and epidemiological models that optimize the timing for control. There is an acute need for managing the downy mildew pathogens infecting cucurbits and hop incited by members of the genus Pseudoperonospora (Pseudoperonospora cubensis clade 1 and 2 isolates and Pseudoperonospora humuli, respectively). A highly specific multiplex TaqMan quantitative polymerase chain reaction (PCR) assay targeting unique sequences in the pathogens' mitochondrial genomes was developed that enables detection of all three taxa in a single multiplexed amplification. An internal control included in the reaction evaluated whether results were influenced by PCR inhibitors that can make it through the DNA extraction process. Reliable quantification of inoculum as low as three sporangia in a sample was observed. The multiplexed assay was tested with DNA extracted from purified sporangia, infected plant tissue, and environmental samples collected on impaction spore traps samplers. The ability to accurately detect and simultaneously quantify all three pathogens in a single multiplexed amplification should improve management options for controlling the diseases they cause.
Collapse
Affiliation(s)
- Sharifa G Crandall
- Crop Improvement and Protection Unit, U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS), Salinas, CA 93905
| | - Marina L Ramon
- Crop Improvement and Protection Unit, U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS), Salinas, CA 93905
| | - Alyssa K Burkhardt
- Crop Improvement and Protection Unit, U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS), Salinas, CA 93905
| | | | - Nanci Adair
- Forage Seed and Cereal Research Unit, U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS), Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - David H Gent
- Forage Seed and Cereal Research Unit, U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS), Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331
| | - Mary K Hausbeck
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Lina M Quesada-Ocampo
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613
| | - Frank N Martin
- Crop Improvement and Protection Unit, U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS), Salinas, CA 93905
| |
Collapse
|
33
|
Hulse-Kemp AM, Bostan H, Chen S, Ashrafi H, Stoffel K, Sanseverino W, Li L, Cheng S, Schatz MC, Garvin T, du Toit LJ, Tseng E, Chin J, Iorizzo M, Van Deynze A. An anchored chromosome-scale genome assembly of spinach improves annotation and reveals extensive gene rearrangements in euasterids. Plant Genome 2021; 14:e20101. [PMID: 34109759 DOI: 10.1002/tpg2.20101] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
Spinach (Spinacia oleracea L.) is a member of the Caryophyllales family, a basal eudicot asterid that consists of sugar beet (Beta vulgaris L. subsp. vulgaris), quinoa (Chenopodium quinoa Willd.), and amaranth (Amaranthus hypochondriacus L.). With the introduction of baby leaf types, spinach has become a staple food in many homes. Production issues focus on yield, nitrogen-use efficiency and resistance to downy mildew (Peronospora effusa). Although genomes are available for the above species, a chromosome-level assembly exists only for quinoa, allowing for proper annotation and structural analyses to enhance crop improvement. We independently assembled and annotated genomes of the cultivar Viroflay using short-read strategy (Illumina) and long-read strategies (Pacific Biosciences) to develop a chromosome-level, genetically anchored assembly for spinach. Scaffold N50 for the Illumina assembly was 389 kb, whereas that for Pacific BioSciences was 4.43 Mb, representing 911 Mb (93% of the genome) in 221 scaffolds, 80% of which are anchored and oriented on a sequence-based genetic map, also described within this work. The two assemblies were 99.5% collinear. Independent annotation of the two assemblies with the same comprehensive transcriptome dataset show that the quality of the assembly directly affects the annotation with significantly more genes predicted (26,862 vs. 34,877) in the long-read assembly. Analysis of resistance genes confirms a bias in resistant gene motifs more typical of monocots. Evolutionary analysis indicates that Spinacia is a paleohexaploid with a whole-genome triplication followed by extensive gene rearrangements identified in this work. Diversity analysis of 75 lines indicate that variation in genes is ample for hypothesis-driven, genomic-assisted breeding enabled by this work.
Collapse
Affiliation(s)
- Amanda M Hulse-Kemp
- Department of Plant Sciences, University of California, Davis, CA, USA
- USDA, Agricultural Research Service, Genomics and Bioinformatics Research Unit, Raleigh, NC, USA
- Department of Crop and Soil Science, North Carolina State University, Raleigh, NC, USA
| | - Hamed Bostan
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, USA
| | - Shiyu Chen
- Department of Plant Sciences, University of California, Davis, CA, USA
| | - Hamid Ashrafi
- Department of Horticulture, North Carolina State University, Raleigh, NC, USA
| | - Kevin Stoffel
- Department of Plant Sciences, University of California, Davis, CA, USA
| | | | | | - Shifeng Cheng
- BGI-Shenzhen, Shenzhen, China
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518060, P. R. China
| | - Michael C Schatz
- Cold Spring Harbor Laboratory, One Bungtown Road, Koch Building 1121, Cold Spring Harbor, NY, 11724, USA
- Departments of Computer Science and Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD, 21218, USA
| | - Tyler Garvin
- Cold Spring Harbor Laboratory, One Bungtown Road, Koch Building 1121, Cold Spring Harbor, NY, 11724, USA
| | - Lindsey J du Toit
- Washington State University, SU Mount Vernon Northwestern Washington Research & Extension Center (NWREC), Mount Vernon, WA, 98273, USA
| | | | - Jason Chin
- Pacific Biosciences, Menlo Park, CA, USA
- DNAnexus Inc, 1975 W El Camino Real #204, Mountain View, CA, 94040, USA
| | - Massimo Iorizzo
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, USA
- Department of Horticulture, North Carolina State University, Raleigh, NC, USA
| | - Allen Van Deynze
- Department of Plant Sciences, University of California, Davis, CA, USA
| |
Collapse
|
34
|
Gao X, Guo P, Wang Z, Chen C, Ren Z. Transcriptome profiling reveals response genes for downy mildew resistance in cucumber. Planta 2021; 253:112. [PMID: 33914134 DOI: 10.1007/s00425-021-03603-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
We discovered a potential defense pathway of cucumber to downy mildew. The signaling that activates the pathways of ROS and lignin accumulation may play an important role in the defense response. Many resistance genes were identified by transcriptome analysis. Downy mildew (DM), caused by Pseudoperonospora cubensis, is one of the most destructive diseases and causes severe yield losses of cucumber. However, the genes and pathways involved in regulating DM resistance were still poorly understood. In our study, we observed that the highly sensitive inbred line 53 (IL53) exhibited more severe disease symptoms than the highly resistant inbred line 51 (IL51) under P. cubensis infection. Furthermore, lignin, limiting the germination and extension of P. cubensis, and H2O2, as a signaling molecule during the resistant process, were both shown to increase, indicating that the signaling that activates these pathways might be responsible for the resistance divergence between IL51 and IL53. Transcriptome analysis, using the resistant and susceptible pools in F2 populations with IL51 and IL53 as parents, showed that a series of differentially expressed genes was involved in multiple functions of defense response: pathogen-associated molecular pattern recognition, signal transduction, reactive oxygen species and lignin accumulation, and transcription regulators. Combining physiological data with transcriptomes, we predicted a potential molecular mechanism of cucumber resistance to DM. Our research provided a foundation for further studies on the mechanism of cucumber resistance to DM.
Collapse
Affiliation(s)
- Xinbin Gao
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit and Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, College of Horticultural Science and Engineering, Shandong Agricultural University, Ministry of Agriculture, Tai'an, 271018, Shandong, China
| | - Pei Guo
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit and Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, College of Horticultural Science and Engineering, Shandong Agricultural University, Ministry of Agriculture, Tai'an, 271018, Shandong, China
| | - Zhiyuan Wang
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit and Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, College of Horticultural Science and Engineering, Shandong Agricultural University, Ministry of Agriculture, Tai'an, 271018, Shandong, China
| | - Chunhua Chen
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit and Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, College of Horticultural Science and Engineering, Shandong Agricultural University, Ministry of Agriculture, Tai'an, 271018, Shandong, China.
| | - Zhonghai Ren
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit and Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, College of Horticultural Science and Engineering, Shandong Agricultural University, Ministry of Agriculture, Tai'an, 271018, Shandong, China.
| |
Collapse
|
35
|
Feiner A, Pitra N, Matthews P, Pillen K, Wessjohann LA, Riewe D. Downy mildew resistance is genetically mediated by prophylactic production of phenylpropanoids in hop. Plant Cell Environ 2021; 44:323-338. [PMID: 33037636 DOI: 10.1111/pce.13906] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/08/2020] [Accepted: 10/01/2020] [Indexed: 05/25/2023]
Abstract
Downy mildew in hop (Humulus lupulus L.) is caused by Pseudoperonospora humuli and generates significant losses in quality and yield. To identify the biochemical processes that confer natural downy mildew resistance (DMR), a metabolome- and genome-wide association study was performed. Inoculation of a high density genotyped F1 hop population (n = 192) with the obligate biotrophic oomycete P. humuli led to variation in both the levels of thousands of specialized metabolites and DMR. We observed that metabolites of almost all major phytochemical classes were induced 48 hr after inoculation. But only a small number of metabolites were found to be correlated with DMR and these were enriched with phenylpropanoids. These metabolites were also correlated with DMR when measured from the non-infected control set. A genome-wide association study revealed co-localization of the major DMR loci and the phenylpropanoid pathway markers indicating that the major contribution to resistance is mediated by these metabolites in a heritable manner. The application of three putative prophylactic phenylpropanoids led to a reduced degree of leaf infection in susceptible genotypes, confirming their protective activity either directly or as precursors of active compounds.
Collapse
Affiliation(s)
- Alexander Feiner
- Plant Science and Breeding, Simon H. Steiner, Hopfen GmbH, Mainburg, Germany
- Deptartment of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry (IPB), Halle/Saale, Germany
| | - Nicholi Pitra
- Research and Development, S.S. Steiner, Inc., New York, USA
| | - Paul Matthews
- Research and Development, S.S. Steiner, Inc., New York, USA
| | - Klaus Pillen
- Institute of Agricultural and Nutritional Sciences, Martin-Luther University (MLU), Halle/Saale, Germany
| | - Ludger A Wessjohann
- Deptartment of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry (IPB), Halle/Saale, Germany
| | - David Riewe
- Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- Institute for Ecological Chemistry, Plant Analysis and Stored Product Protection, Julius Kühn-Institute (JKI), Federal Research Centre for Cultivated Plants, Berlin, Germany
| |
Collapse
|
36
|
Van der Heyden H, Bilodeau GJ, Carisse O, Charron JB. Monitoring of Peronospora destructor Primary and Secondary Inoculum by Real-Time qPCR. Plant Dis 2020; 104:3183-3191. [PMID: 33044917 DOI: 10.1094/pdis-03-20-0687-re] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Onion downy mildew (ODM), caused by Peronospora destructor, is a serious threat for onion growers worldwide. In southwestern Québec, Canada, a steady increase in occurrence of ODM has been observed since the mid-2000s. On onion, P. destructor can develop local and systemic infections producing numerous sporangia which act as initial inoculum locally and also for neighboring areas. It also produces oospores capable of surviving in soils and tissues for a prolonged period of time. A recent study showed that ODM epidemics are strongly associated with weather conditions related to production and survival of overwintering inoculum, stressing the need to understand the role of primary (initial) and secondary inoculum. However, P. destructor is an obligate biotrophic pathogen, which complicates the study of inoculum sources. This study aimed at developing a molecular assay specific to P. destructor, allowing its quantification in environmental samples. In this study, a reliable and sensitive hydrolysis probe-based assay multiplexed with an internal control was developed on the internal transcribed spacer (ITS) region to quantify soil- and airborne inoculum of P. destructor. The assay specificity was tested against 17 isolates of P. destructor obtained from different locations worldwide, other members of the order Peronosporales, and various onion pathogens. Validation with artificially inoculated soil and air samples suggested a sensitivity of less than 10 sporangia g-1 of dry soil and 1 sporangium m-3 of air. Validation with environmental air samples shows a linear relationship between microscopic and real-time quantitative PCR counts. In naturally infested soils, inoculum ranged from 0 to 162 sporangia equivalent g-1 of dry soil, which supported the hypothesis of overwintering under northern climates. This assay will be useful for primary and secondary inoculum monitoring to help characterize ODM epidemiology and could be used for daily tactical and short-term strategic decision-making.
Collapse
Affiliation(s)
- Hervé Van der Heyden
- Cie de Recherche Phytodata, 291 rue de la coopérative, Sherrington, QC, Canada
- Department of Plant Science, McGill University, Macdonald Campus, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, Canada
| | | | - Odile Carisse
- Agriculture and Agri-Food Canada, 430 Boulevard Gouin, St-Jean-sur-Richelieu, QC, Canada
| | - Jean-Benoit Charron
- Department of Plant Science, McGill University, Macdonald Campus, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, Canada
| |
Collapse
|
37
|
McGrath MT. Efficacy of Conventional Fungicides for Downy Mildew in Field-Grown Sweet Basil in the United States. Plant Dis 2020; 104:2967-2972. [PMID: 32830999 DOI: 10.1094/pdis-11-19-2382-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Application of fungicides has been the main management practice for Peronospora belbahrii, which is the most important pathogen of sweet basil in the United States. Six replicated experiments were conducted between 2010 and 2016 with field-grown basil of a susceptible cultivar exposed to naturally occurring wind-dispersed sporangiospores of P. belbahrii to evaluate conventional fungicides registered for basil downy mildew in the United States and in development for this use. This project revealed the importance for successful management of using a preventive fungicide application schedule, maintaining a 7-day application interval, and using application equipment designed to provide thorough spray coverage to plants (drop nozzles). Fungicide efficacy was assessed based on incidence of symptomatic leaves rather than disease severity, which is stringent but realistic because there is zero tolerance for disease on fresh-market herbs. Most fungicides were tested as the formulated product marketed in the United States. Oxathiapiprolin was tested as experimental formulations. Its trade name is Orondis. Overall best control was achieved in 2016. Excellent control (99% based on AUDPC values) was obtained with four fungicide programs with oxathiapiprolin, Revus, and ProPhyt, indicating this combination of chemistry was more important than specific timing for each fungicide. Ranman applied in alternation with Revus plus K-Phite was not quite as effective (89% control); this treatment was ineffective in 2015 when the 7-day spray interval was not maintained. Best treatment in 2015 was Quadris applied in alternation with Revus plus oxathiapiprolin for two of three Revus applications. Two different alternations of these fungicides also were effective. But Quadris alternated with Revus was ineffective. When tested singly, the most effective fungicides in 2013 (listed in order based on AUDPC values) were Zampro, Revus, oxathiapiprolin, and Ranman. ProPhyt was effective in 2013 but not in 2012, when another phosphorous acid fungicide, K-Phite, also was ineffective. Only oxathiapiprolin and Zampro were effective in the 2012 experiment; Revus and Ranman were ineffective. Presidio was ineffective both years. Based on the results from this study, Orondis is the most effective fungicide among those evaluated for managing basil downy mildew, and Zampro is second. Neither were labeled for this use on field-grown basil as of June 2020. Ranman applied in alternation with Revus plus K-Phite, a commonly recommended program of labeled fungicides, provided very good control.
Collapse
Affiliation(s)
- Margaret Tuttle McGrath
- Plant Pathology and Plant-Microbe Biology Section, SIPS, Cornell University, Long Island Horticultural Research and Extension Center, Riverhead, NY 11901
| |
Collapse
|
38
|
Dhillon B, Feng C, Villarroel-Zeballos MI, Castroagudin VL, Bhattarai G, Klosterman SJ, Correll JC. Sporangiospore Viability and Oospore Production in the Spinach Downy Mildew Pathogen, Peronospora effusa. Plant Dis 2020; 104:2634-2641. [PMID: 32787734 DOI: 10.1094/pdis-02-20-0334-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Downy mildew of spinach, caused by the obligate pathogen Peronospora effusa, remains the most important constraint in the major spinach production areas in the United States. This disease can potentially be initiated by asexual sporangiospores via "green bridges", sexually derived oospores from seed or soil, or dormant mycelium. However, the relative importance of the various types of primary inoculum is not well known. The ability of P. effusa sporangiospores to withstand abiotic stress, such as desiccation, and remain viable during short- and long-distance dispersal and the ability of oospores to germinate and infect seedlings remain unclear. Thus, the primary objectives of this research were to evaluate the impact of desiccation on sporangiospore survival and infection efficiency and examine occurrence, production, and germination of oospores. Results indicate that desiccation significantly reduces sporangiospore viability as well as infection potential. Leaf wetness duration of 4 h was needed for disease establishment by spinach downy mildew sporangiospores. Oospores were observed in leaves of numerous commercial spinach cultivars grown in California in 2018 and Arizona in 2019. Frequency of occurrence varied between the two states-years. The presence of opposite mating types in spinach production areas in the United States was demonstrated by pairing isolates in controlled crosses and producing oospores on detached leaves as well as intact plants. Information from the study of variables that affect sporangiospore viability and oospore production will help in improving our understanding of the epidemiology of this important pathogen, which has implications for management of spinach downy mildew.
Collapse
Affiliation(s)
- Braham Dhillon
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701
| | - Chunda Feng
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701
| | | | | | - Gehendra Bhattarai
- Department of Horticulture, University of Arkansas, Fayetteville, AR 72701
| | | | - James C Correll
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701
| |
Collapse
|
39
|
Wallace EC, D'Arcangelo KN, Quesada-Ocampo LM. Population Analyses Reveal Two Host-Adapted Clades of Pseudoperonospora cubensis, the Causal Agent of Cucurbit Downy Mildew, on Commercial and Wild Cucurbits. Phytopathology 2020; 110:1578-1587. [PMID: 32314948 DOI: 10.1094/phyto-01-20-0009-r] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Pseudoperonospora cubensis, the causal agent of cucurbit downy mildew, is an airborne, obligate oomycete pathogen that re-emerged in 2004 and causes foliar disease and yield losses in all major cucurbit crops in the United States. Approximately 60 species in the family Cucurbitaceae have been reported as hosts of P. cubensis. Commercial hosts including cucumber, cantaloupe, pumpkin, squash, and watermelon are grown in North Carolina and many host species occur in the wild as weeds. Little is known about the contribution of wild cucurbits to the yearly epidemic; thus, this study aimed to determine the role of commercial and wild cucurbits in the structuring of P. cubensis populations in North Carolina, a region with high pathogen diversity. Ten microsatellite markers were used to analyze 385 isolates from six commercial and four wild cucurbits from three locations representing different growing regions across North Carolina. Population analyses revealed that wild and commercial cucurbits are hosts of P. cubensis in the United States, that host is the main factor structuring P. cubensis populations, and that P. cubensis has two distinct, host-adapted clades at the cucurbit species level, with clade 1 showing random mating and evidence of recombination and clade 2 showing nonrandom mating and no evidence of recombination. Our findings have implications for disease management because clade-specific factors such as host susceptibility and inoculum availability of each clade by region may influence P. cubensis outbreaks in different commercial cucurbits, timing of fungicide applications, and phenotyping for breeding efforts.
Collapse
Affiliation(s)
- E C Wallace
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613
| | - K N D'Arcangelo
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613
| | - L M Quesada-Ocampo
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613
| |
Collapse
|
40
|
Rahman A, Góngora-Castillo E, Bowman MJ, Childs KL, Gent DH, Martin FN, Quesada-Ocampo LM. Genome Sequencing and Transcriptome Analysis of the Hop Downy Mildew Pathogen Pseudoperonospora humuli Reveal Species-Specific Genes for Molecular Detection. Phytopathology 2019; 109:1354-1366. [PMID: 30939079 DOI: 10.1094/phyto-11-18-0431-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Pseudoperonospora humuli is an obligate oomycete pathogen of hop (Humulus lupulus) that causes downy mildew, an important disease in most production regions in the Northern Hemisphere. The pathogen can cause a systemic infection in hop, overwinter in the root system, and infect propagation material. Substantial yield loss may occur owing to P. humuli infection of strobiles (seed cones), shoots, and cone-bearing branches. Fungicide application and cultural practices are the primary methods to manage hop downy mildew. However, effective, sustainable, and cost-effective management of downy mildew can be improved by developing early detection systems to inform on disease risk and timely fungicide application. However, no species-specific diagnostic assays or genomic resources are available for P. humuli. The genome of the P. humuli OR502AA isolate was partially sequenced using Illumina technology and assembled with ABySS. The assembly had a minimum scaffold length of 500 bp and an N50 (median scaffold length of the assembled genome) of 19.2 kbp. A total number of 18,656 genes were identified using MAKER standard gene predictions. Additionally, transcriptome assemblies were generated using RNA-seq and Trinity for seven additional P. humuli isolates. Bioinformatics analyses of next generation sequencing reads of P. humuli and P. cubensis (a closely related sister species) identified 242 candidate species-specific P. humuli genes that could be used as diagnostic molecular markers. These candidate genes were validated using polymerase chain reaction against a diverse collection of isolates from P. humuli, P. cubensis, and other oomycetes. Overall, four diagnostic markers were found to be uniquely present in P. humuli. These candidate markers identified through comparative genomics can be used for pathogen diagnostics in propagation material, such as rhizomes and vegetative cuttings, or adapted for biosurveillance of airborne sporangia, an important source of inoculum in hop downy mildew epidemics.
Collapse
Affiliation(s)
- A Rahman
- 1Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
| | - E Góngora-Castillo
- 1Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
- 2Department of Biotechnology, Yucatan Center for Scientific Research, 97205 Mérida, Yucatán, México
| | - M J Bowman
- 3Department of Plant Biology, Michigan State University, East Lansing, MI 48823, U.S.A
| | - K L Childs
- 3Department of Plant Biology, Michigan State University, East Lansing, MI 48823, U.S.A
| | - D H Gent
- 4Forage Seed and Cereal Research Unit, U.S. Department of Agriculture-Agricultural Research Service and Oregon State University, Corvallis 97331, OR, U.S.A
| | - F N Martin
- 5Crop Improvement and Protection Research Station, U.S. Department of Agriculture-Agricultural Research Service, Salinas, CA 93905, U.S.A
| | - L M Quesada-Ocampo
- 1Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695-7613, U.S.A
| |
Collapse
|
41
|
Luan Q, Chen C, Liu M, Li Q, Wang L, Ren Z. CsWRKY50 mediates defense responses to Pseudo peronospora cubensis infection in Cucumis sativus. Plant Sci 2019; 279:59-69. [PMID: 30709494 DOI: 10.1016/j.plantsci.2018.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 10/11/2018] [Accepted: 11/09/2018] [Indexed: 05/13/2023]
Abstract
The cucumber (Cucumis sativus L.), an economically important vegetable crop, is often infected by Pseudoperonospora cubensis (P. cubensis), which results in inhibited growth and reduced yield. WRKY transcription factors (TFs) play critical roles in plant disease resistance. However, little is known about the function of WRKY TFs in cucumber downy mildew resistance. In this study, we reported that CsWRKY50, a cucumber WRKY subgroup Ⅱc TF localized in the nucleus, plays an important role in cucumber defense responses to downy mildew. In addition, several putative cis-acting elements involved in abiotic stress responsiveness were also identified in the CsWRKY50 promoter. Expression analysis revealed that CsWRKY50 can be induced by P. cubensis infection, abiotic stress and diverse signaling molecules. The overexpression of CsWRKY50 in cucumber enhanced the resistance of the plant to the fungal pathogen P. cubensis. In addition, less ROS accumulated in 35S:CsWRKY50 transgenic plants infected by the pathogen due to the higher expression levels of antioxidant enzymes. Importantly, after P. cubensis infection, the transcript levels of several hormone-related defense genes were also upregulated in transgenic plants, including SA- and JA-responsive genes and SA-synthesis genes. Collectively, our results indicate that CsWRKY50 positively regulates cucumber disease resistance to P. cubensis via multiple signaling pathways.
Collapse
Affiliation(s)
- Qianqian Luan
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
| | - Chunhua Chen
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
| | - Mengyu Liu
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
| | - Qiang Li
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
| | - Lina Wang
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
| | - Zhonghai Ren
- State Key Laboratory of Crop Biology, Shandong Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops in Huang-Huai Region, Ministry of Agriculture, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, PR China.
| |
Collapse
|
42
|
Zhang K, Wang X, Zhu W, Qin X, Xu J, Cheng C, Lou Q, Li J, Chen J. Complete resistance to powdery mildew and partial resistance to downy mildew in a Cucumis hystrix introgression line of cucumber were controlled by a co-localized locus. Theor Appl Genet 2018; 131:2229-2243. [PMID: 30078164 DOI: 10.1007/s00122-018-3150-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/23/2018] [Indexed: 05/16/2023]
Abstract
Key message A single recessive gene for complete resistance to powdery mildew and a major-effect QTL for partial resistance to downy mildew were co-localized in a Cucumis hystrix introgression line of cucumber. Downy mildew (DM) and powdery mildew (PM) are two major foliar diseases in cucumber. DM resistance (DMR) and PM resistance (PMR) may share common components; however, the genetic relationship between them remains unclear. IL52, a Cucumis hystrix introgression line of cucumber which has been reported to possess DMR, was recently identified to exhibit PMR as well. In this study, a single recessive gene pm for PMR was mapped to an approximately 468-kb region on chromosome 5 with 155 recombinant inbred lines (RILs) and 193 F2 plants derived from the cross between a susceptible line 'changchunmici' and IL52. Interestingly, pm was co-localized with the major-effect DMR QTL dm5.2 confirmed by combining linkage analysis and BSA-seq, which was consistent with the observed linkage of DMR and PMR in IL52. Further, phenotype-genotype correlation analysis of DMR and PMR in the RILs indicated that the co-localized locus pm/dm5.2 confers complete resistance to PM and partial resistance to DM. Seven candidate genes for DMR were identified within dm5.2 by BSA-seq analysis, of which Csa5M622800.1, Csa5M622830.1 and Csa5M623490.1 were also the same candidate genes for PMR. A single nucleotide polymorphism that is present in the 3' untranslated region (3'UTR) of Csa5M622830.1 co-segregated perfectly with PMR. The GATA transcriptional factor gene Csa5M622830.1 may be a likely candidate gene for DMR and PMR. This study has provided a clear evidence for the relationship between DMR and PMR in IL52 and sheds new light on the potential value of IL52 for cucumber DMR and PMR breeding program.
Collapse
Affiliation(s)
- Kaijing Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China
| | - Xing Wang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China
| | - Wenwei Zhu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China
| | - Xiaodong Qin
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China
| | - Jian Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China
| | - Chunyan Cheng
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China
| | - Qunfeng Lou
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China
| | - Ji Li
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China.
| | - Jinfeng Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Weigang Street No. 1, Nanjing, 210095, China.
| |
Collapse
|
43
|
Vandelle E, Vannozzi A, Wong D, Danzi D, Digby AM, Dal Santo S, Astegno A. Identification, characterization, and expression analysis of calmodulin and calmodulin-like genes in grapevine (Vitis vinifera) reveal likely roles in stress responses. Plant Physiol Biochem 2018; 129:221-237. [PMID: 29908490 DOI: 10.1016/j.plaphy.2018.06.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 05/09/2018] [Accepted: 06/02/2018] [Indexed: 05/23/2023]
Abstract
Calcium (Ca2+) is an ubiquitous key second messenger in plants, where it modulates many developmental and adaptive processes in response to various stimuli. Several proteins containing Ca2+ binding domain have been identified in plants, including calmodulin (CaM) and calmodulin-like (CML) proteins, which play critical roles in translating Ca2+ signals into proper cellular responses. In this work, a genome-wide analysis conducted in Vitis vinifera identified three CaM- and 62 CML-encoding genes. We assigned gene family nomenclature, analyzed gene structure, chromosomal location and gene duplication, as well as protein motif organization. The phylogenetic clustering revealed a total of eight subgroups, including one unique clade of VviCaMs distinct from VviCMLs. VviCaMs were found to contain four EF-hand motifs whereas VviCML proteins have one to five. Most of grapevine CML genes were intronless, while VviCaMs were intron rich. All the genes were well spread among the 19 grapevine chromosomes and displayed a high level of duplication. The expression profiling of VviCaM/VviCML genes revealed a broad expression pattern across all grape organs and tissues at various developmental stages, and a significant modulation in biotic stress-related responses. Our results highlight the complexity of CaM/CML protein family also in grapevine, supporting the versatile role of its different members in modulating cellular responses to various stimuli, in particular to biotic stresses. This work lays the foundation for further functional and structural studies on specific grapevine CaMs/CMLs in order to better understand the role of Ca2+-binding proteins in grapevine and to explore their potential for further biotechnological applications.
Collapse
Affiliation(s)
- Elodie Vandelle
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Alessandro Vannozzi
- Department of Agronomy, Food, Natural Resources, Animals, and Environment, University of Padova, 35020 Legnaro, Padova, Italy.
| | - Darren Wong
- Ecology and Evolution, Research School of Biology, The Australian National University, Acton ACT 2601, Australia.
| | - Davide Danzi
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Anne-Marie Digby
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Silvia Dal Santo
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Alessandra Astegno
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| |
Collapse
|
44
|
Divilov K, Barba P, Cadle-Davidson L, Reisch BI. Single and multiple phenotype QTL analyses of downy mildew resistance in interspecific grapevines. Theor Appl Genet 2018; 131:1133-1143. [PMID: 29417162 PMCID: PMC5895686 DOI: 10.1007/s00122-018-3065-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/26/2018] [Indexed: 05/20/2023]
Abstract
KEY MESSAGE Downy mildew resistance across days post-inoculation, experiments, and years in two interspecific grapevine F1 families was investigated using linear mixed models and Bayesian networks, and five new QTL were identified. Breeding grapevines for downy mildew disease resistance has traditionally relied on qualitative gene resistance, which can be overcome by pathogen evolution. Analyzing two interspecific F1 families, both having ancestry derived from Vitis vinifera and wild North American Vitis species, across 2 years and multiple experiments, we found multiple loci associated with downy mildew sporulation and hypersensitive response in both families using a single phenotype model. The loci explained between 7 and 17% of the variance for either phenotype, suggesting a complex genetic architecture for these traits in the two families studied. For two loci, we used RNA-Seq to detect differentially transcribed genes and found that the candidate genes at these loci were likely not NBS-LRR genes. Additionally, using a multiple phenotype Bayesian network analysis, we found effects between the leaf trichome density, hypersensitive response, and sporulation phenotypes. Moderate-high heritabilities were found for all three phenotypes, suggesting that selection for downy mildew resistance is an achievable goal by breeding for either physical- or non-physical-based resistance mechanisms, with the combination of the two possibly providing durable resistance.
Collapse
Affiliation(s)
- Konstantin Divilov
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Paola Barba
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
- Instituto de Investigaciones Agropecuarias, INIA La Platina, Santiago, Chile
| | | | - Bruce I Reisch
- Horticulture Section, School of Integrative Plant Science, New York State Agricultural Experiment Station, Cornell University, Geneva, NY, USA.
| |
Collapse
|
45
|
Pyne RM, Honig JA, Vaiciunas J, Wyenandt CA, Simon JE. Population structure, genetic diversity and downy mildew resistance among Ocimum species germplasm. BMC Plant Biol 2018; 18:69. [PMID: 29685108 PMCID: PMC5914031 DOI: 10.1186/s12870-018-1284-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 04/10/2018] [Indexed: 05/09/2023]
Abstract
BACKGROUND The basil (Ocimum spp.) genus maintains a rich diversity of phenotypes and aromatic volatiles through natural and artificial outcrossing. Characterization of population structure and genetic diversity among a representative sample of this genus is severely lacking. Absence of such information has slowed breeding efforts and the development of sweet basil (Ocimum basilicum L.) with resistance to the worldwide downy mildew epidemic, caused by the obligate oomycete Peronospora belbahrii. In an effort to improve classification of relationships 20 EST-SSR markers with species-level transferability were developed and used to resolve relationships among a diverse panel of 180 Ocimum spp. accessions with varying response to downy mildew. RESULTS Results obtained from nested Bayesian model-based clustering, analysis of molecular variance and unweighted pair group method using arithmetic average (UPGMA) analyses were synergized to provide an updated phylogeny of the Ocimum genus. Three (major) and seven (sub) population (cluster) models were identified and well-supported (P < 0.001) by PhiPT (ΦPT) values of 0.433 and 0.344, respectively. Allelic frequency among clusters supported previously developed hypotheses of allopolyploid genome structure. Evidence of cryptic population structure was demonstrated for the k1 O. basilicum cluster suggesting prevalence of gene flow. UPGMA analysis provided best resolution for the 36-accession, DM resistant k3 cluster with consistently strong bootstrap support. Although the k3 cluster is a rich source of DM resistance introgression of resistance into the commercially important k1 accessions is impeded by reproductive barriers as demonstrated by multiple sterile F1 hybrids. The k2 cluster located between k1 and k3, represents a source of transferrable tolerance evidenced by fertile backcross progeny. The 90-accession k1 cluster was largely susceptible to downy mildew with accession 'MRI' representing the only source of DM resistance. CONCLUSIONS High levels of genetic diversity support the observed phenotypic diversity among Ocimum spp. accessions. EST-SSRs provided a robust evaluation of molecular diversity and can be used for additional studies to increase resolution of genetic relationships in the Ocimum genus. Elucidation of population structure and genetic relationships among Ocimum spp. germplasm provide the foundation for improved DM resistance breeding strategies and more rapid response to future disease outbreaks.
Collapse
Affiliation(s)
- Robert M. Pyne
- Department of Plant Biology, Rutgers, the State University of New Jersey, Foran Hall, 59 Dudley Rd, New Brunswick, NJ 08901 USA
| | - Josh A. Honig
- Department of Plant Biology, Rutgers, the State University of New Jersey, Foran Hall, 59 Dudley Rd, New Brunswick, NJ 08901 USA
| | - Jennifer Vaiciunas
- Department of Plant Biology, Rutgers, the State University of New Jersey, Foran Hall, 59 Dudley Rd, New Brunswick, NJ 08901 USA
| | - Christian A. Wyenandt
- Department of Plant Biology, Rutgers, the State University of New Jersey, Foran Hall, 59 Dudley Rd, New Brunswick, NJ 08901 USA
| | - James E. Simon
- Department of Plant Biology, Rutgers, the State University of New Jersey, Foran Hall, 59 Dudley Rd, New Brunswick, NJ 08901 USA
| |
Collapse
|
46
|
Wang Y, VandenLangenberg K, Wen C, Wehner TC, Weng Y. QTL mapping of downy and powdery mildew resistances in PI 197088 cucumber with genotyping-by-sequencing in RIL population. Theor Appl Genet 2018; 131:597-611. [PMID: 29159421 DOI: 10.1007/s00122-017-3022-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/10/2017] [Indexed: 05/02/2023]
Abstract
Host resistances in PI 197088 cucumber to downy and powdery mildew pathogens are conferred by 11 (3 with major effect) and 4 (1 major effect) QTL, respectively, and three of which are co-localized. The downy mildew (DM) and powdery mildew (PM) are the two most important foliar diseases of cucurbit crops worldwide. The cucumber accession PI 197088 exhibits high-level resistances to both pathogens. Here, we reported QTL mapping results for DM and PM resistances with 148 recombinant inbred lines from a cross between PI 197088 and the susceptible line 'Coolgreen'. Phenotypic data on responses to natural DM and PM infection were collected in multi-year and multi-location replicated field trials. A high-density genetic map with 2780 single nucleotide polymorphisms (SNPs) from genotyping-by-sequencing and 55 microsatellite markers was developed, which revealed genomic regions with segregation distortion and mis-assemblies in the '9930' cucumber draft genome. QTL analysis identified 11 and 4 QTL for DM and PM resistances accounting for more than 73.5 and 63.0% total phenotypic variance, respectively. Among the 11 DM resistance QTL, dm5.1, dm5.2, and dm5.3 were major-effect contributing QTL, whereas dm1.1, dm2.1, and dm6.2 conferred susceptibility. Of the 4 QTL for PM resistance, pm5.1 was the major-effect QTL explaining 32.4% phenotypic variance and the minor-effect QTL pm6.1 contributed to disease susceptibility. Three PM QTL, pm2.1, pm5.1, and pm6.1, were co-localized with DM QTL dm2.1, dm5.2, and dm6.1, respectively, which was consistent with the observed linkage of PM and DM resistances in PI 197088. The genetic architecture of DM resistance in PI 197088 and another resistant line WI7120 (PI 330628) was compared, and the potential of using PI 197088 in cucumber breeding for downy and powdery mildew resistances is discussed.
Collapse
Affiliation(s)
- Yuhui Wang
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA
| | - Kyle VandenLangenberg
- Horticultural Science Department, North Carolina State University, Raleigh, NC, 27695, USA
| | - Changlong Wen
- Beijing Academy of Agricultural and Forestry Sciences, Beijing, 100097, China
| | - Todd C Wehner
- Horticultural Science Department, North Carolina State University, Raleigh, NC, 27695, USA
| | - Yiqun Weng
- Horticulture Department, University of Wisconsin, Madison, WI, 53706, USA.
- USDA-ARS Vegetable Crops Research Unit, Madison, WI, 53705, USA.
| |
Collapse
|
47
|
Ma GJ, Markell SG, Song QJ, Qi LL. Genotyping-by-sequencing targeting of a novel downy mildew resistance gene Pl 20 from wild Helianthus argophyllus for sunflower (Helianthus annuus L.). Theor Appl Genet 2017; 130:1519-1529. [PMID: 28432412 DOI: 10.1007/s00122-017-2906-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/07/2017] [Indexed: 05/20/2023]
Abstract
Genotyping-by-sequencing revealed a new downy mildew resistance gene, Pl 20 , from wild Helianthus argophyllus located on linkage group 8 of the sunflower genome and closely linked to SNP markers that facilitate the marker-assisted selection of resistance genes. Downy mildew (DM), caused by Plasmopara halstedii, is one of the most devastating and yield-limiting diseases of sunflower. Downy mildew resistance identified in wild Helianthus argophyllus accession PI 494578 was determined to be effective against the predominant and virulent races of P. halstedii occurring in the United States. The evaluation of 114 BC1F2:3 families derived from the cross between HA 89 and PI 494578 against P. halstedii race 734 revealed that single dominant gene controls downy mildew resistance in the population. Genotyping-by-sequencing analysis conducted in the BC1F2 population indicated that the DM resistance gene derived from wild H. argophyllus PI 494578 is located on the upper end of the linkage group (LG) 8 of the sunflower genome, as was determined single nucleotide polymorphism (SNP) markers associated with DM resistance. Analysis of 11 additional SNP markers previously mapped to this region revealed that the resistance gene, named Pl 20 , co-segregated with four markers, SFW02745, SFW09076, S8_11272025, and S8_11272046, and is flanked by SFW04358 and S8_100385559 at an interval of 1.8 cM. The newly discovered P. halstedii resistance gene has been introgressed from wild species into cultivated sunflower to provide a novel gene with DM resistance. The homozygous resistant individuals were selected from BC2F2 progenies with the use of markers linked to the Pl 20 gene, and these lines should benefit the sunflower community for Helianthus improvement.
Collapse
Affiliation(s)
- G J Ma
- Department of Plant Pathology, North Dakota State University, Fargo, ND, 58108, USA
| | - S G Markell
- Department of Plant Pathology, North Dakota State University, Fargo, ND, 58108, USA
| | - Q J Song
- Soybean Genomics and Improvement Lab, USDA-Agricultural Research Service, Beltsville, MD, 20705-2350, USA
| | - L L Qi
- Red River Valley Agricultural Research Center, USDA-Agricultural Research Service, 1605 Albrecht Blvd N, Fargo, ND, 58102-2765, USA.
| |
Collapse
|
48
|
Jiao L, Zhang Y, Lu J. Overexpression of a stress-responsive U-box protein gene VaPUB affects the accumulation of resistance related proteins in Vitis vinifera 'Thompson Seedless'. Plant Physiol Biochem 2017; 112:53-63. [PMID: 28039816 DOI: 10.1016/j.plaphy.2016.12.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 12/21/2016] [Accepted: 12/22/2016] [Indexed: 05/25/2023]
Abstract
Many U-box proteins have been identified and characterized as important factors against environmental stresses such as chilling, heat, salinity and pathogen attack in plant. Our previous research reported the cloning of a novel U-box protein gene VaPUB from Vitis amurensis 'Zuoshanyi' grape and suggested a function of it in related to cold stress in the model plant Arabidopsis system. In this study, the role of VaPUB in response to biotic and abiotic stress was further analyzed in the homologous grapevine system by studying the transcript regulation and the protein accumulation in VaPUB transgenic vines. The expression analysis assay shown that VaPUB was significantly up-regulated 6 h after cold treatment and as early as 2 h post inoculation with Plasmopara viticola, a pathogen causing downy mildew disease in grapevine. Over-expressing VaPUB in V. Vinifera 'Thompson Seedless' affected the microstructure of leaves. The proteome assay shown that the accumulation of pathogenesis-related protein PR10 and many proteins involved in carbon and energy metabolism, oxidation reaction and protein metabolism were significantly altered in transgenic vines. In comparison with wild type plants, the expression level of PR10 family genes was significantly decreased in VaPUB transgenic vines under P. viticola treatment or cold stress. Results from this study showed that the U-box protein gene PUB quickly responded to both biotic stress and abiotic stress and significantly influenced the accumulation of resistance related proteins in grapevine.
Collapse
Affiliation(s)
- Li Jiao
- The Viticulture and Enology Program, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China; Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai JiaoTong University, Shanghai, 200240, China
| | - Yali Zhang
- The Viticulture and Enology Program, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Jiang Lu
- The Viticulture and Enology Program, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China; Center for Viticulture and Enology, School of Agriculture and Biology, Shanghai JiaoTong University, Shanghai, 200240, China.
| |
Collapse
|
49
|
Win KT, Vegas J, Zhang C, Song K, Lee S. QTL mapping for downy mildew resistance in cucumber via bulked segregant analysis using next-generation sequencing and conventional methods. Theor Appl Genet 2017; 130:199-211. [PMID: 27714417 DOI: 10.1007/s00122-016-2806-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/26/2016] [Indexed: 05/21/2023]
Abstract
QTL mapping using NGS-assisted BSA was successfully applied to an F 2 population for downy mildew resistance in cucumber. QTLs detected by NGS-assisted BSA were confirmed by conventional QTL analysis. Downy mildew (DM), caused by Pseudoperonospora cubensis, is one of the most destructive foliar diseases in cucumber. QTL mapping is a fundamental approach for understanding the genetic inheritance of DM resistance in cucumber. Recently, many studies have reported that a combination of bulked segregant analysis (BSA) and next-generation sequencing (NGS) can be a rapid and cost-effective way of mapping QTLs. In this study, we applied NGS-assisted BSA to QTL mapping of DM resistance in cucumber and confirmed the results by conventional QTL analysis. By sequencing two DNA pools each consisting of ten individuals showing high resistance and susceptibility to DM from a F2 population, we identified single nucleotide polymorphisms (SNPs) between the two pools. We employed a statistical method for QTL mapping based on these SNPs. Five QTLs, dm2.2, dm4.1, dm5.1, dm5.2, and dm6.1, were detected and dm2.2 showed the largest effect on DM resistance. Conventional QTL analysis using the F2 confirmed dm2.2 (R 2 = 10.8-24 %) and dm5.2 (R 2 = 14-27.2 %) as major QTLs and dm4.1 (R 2 = 8 %) as two minor QTLs, but could not detect dm5.1 and dm6.1. A new QTL on chromosome 2, dm2.1 (R 2 = 28.2 %) was detected by the conventional QTL method using an F3 population. This study demonstrated the effectiveness of NGS-assisted BSA for mapping QTLs conferring DM resistance in cucumber and revealed the unique genetic inheritance of DM resistance in this population through two distinct major QTLs on chromosome 2 that mainly harbor DM resistance.
Collapse
Affiliation(s)
- Khin Thanda Win
- Plant Genomics Laboratory, Department of Plant Biotechnology, College of Life Sciences, Sejong University, 209 Neungdong-ro, Gwanjing-gu, Seoul, 143-747, Republic of Korea
| | - Juan Vegas
- Plant Genomics Laboratory, Department of Plant Biotechnology, College of Life Sciences, Sejong University, 209 Neungdong-ro, Gwanjing-gu, Seoul, 143-747, Republic of Korea
- SESVANDERHAVE Belgium, Industriepark 15, 3300, Tienen, Belgium
| | - Chunying Zhang
- Plant Genomics Laboratory, Department of Plant Biotechnology, College of Life Sciences, Sejong University, 209 Neungdong-ro, Gwanjing-gu, Seoul, 143-747, Republic of Korea
| | - Kihwan Song
- Plant Genomics Laboratory, Department of Plant Biotechnology, College of Life Sciences, Sejong University, 209 Neungdong-ro, Gwanjing-gu, Seoul, 143-747, Republic of Korea
- Plant Engineering Research Institute, Sejong University, 209 Neungdong-ro, Gwanjing-gu, Seoul, 143-747, Republic of Korea
| | - Sanghyeob Lee
- Plant Genomics Laboratory, Department of Plant Biotechnology, College of Life Sciences, Sejong University, 209 Neungdong-ro, Gwanjing-gu, Seoul, 143-747, Republic of Korea.
- Plant Engineering Research Institute, Sejong University, 209 Neungdong-ro, Gwanjing-gu, Seoul, 143-747, Republic of Korea.
| |
Collapse
|
50
|
Zhang ZW, Ma GJ, Zhao J, Markell SG, Qi LL. Discovery and introgression of the wild sunflower-derived novel downy mildew resistance gene Pl 19 in confection sunflower (Helianthus annuus L.). Theor Appl Genet 2017; 130:29-39. [PMID: 27677630 DOI: 10.1007/s00122-016-2786-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 09/03/2016] [Indexed: 05/20/2023]
Abstract
A new downy mildew resistance gene, Pl 19 , was identified from wild Helianthus annuus accession PI 435414, introduced to confection sunflower, and genetically mapped to linkage group 4 of the sunflower genome. Wild Helianthus annuus accession PI 435414 exhibited resistance to downy mildew, which is one of the most destructive diseases to sunflower production globally. Evaluation of the 140 BC1F2:3 families derived from the cross of CMS CONFSCLB1 and PI 435414 against Plasmopara halstedii race 734 revealed that a single dominant gene controls downy mildew resistance in the population. Bulked segregant analysis conducted in the BC1F2 population with 860 simple sequence repeat (SSR) markers indicated that the resistance derived from wild H. annuus was associated with SSR markers located on linkage group (LG) 4 of the sunflower genome. To map and tag this resistance locus, designated Pl 19 , 140 BC1F2 individuals were used to construct a linkage map of the gene region. Two SSR markers, ORS963 and HT298, were linked to Pl 19 within a distance of 4.7 cM. After screening 27 additional single nucleotide polymorphism (SNP) markers previously mapped to this region, two flanking SNP markers, NSA_003564 and NSA_006089, were identified as surrounding the Pl 19 gene at a distance of 0.6 cM from each side. Genetic analysis indicated that Pl 19 is different from Pl 17 , which had previously been mapped to LG4, but is closely linked to Pl 17 . This new gene is highly effective against the most predominant and virulent races of P. halstedii currently identified in North America and is the first downy mildew resistance gene that has been transferred to confection sunflower. The selected resistant germplasm derived from homozygous BC2F3 progeny provides a novel gene for use in confection sunflower breeding programs.
Collapse
Affiliation(s)
- Z W Zhang
- Department of Agronomy, Inner Mongolia Agricultural University, Huhhot, 010019, Inner Mongolia, China
| | - G J Ma
- Department of Plant Pathology, North Dakota State University, Fargo, ND, 58108, USA
| | - J Zhao
- Department of Agronomy, Inner Mongolia Agricultural University, Huhhot, 010019, Inner Mongolia, China
| | - S G Markell
- Department of Plant Pathology, North Dakota State University, Fargo, ND, 58108, USA
| | - L L Qi
- Northern Crop Science Laboratory, USDA-Agricultural Research Service, 1605 Albrecht Blvd. N, Fargo, ND, 58102-2765, USA.
| |
Collapse
|