1
|
Huizinga S, Bouwmeester HJ. Role of Strigolactones in the Host Specificity of Broomrapes and Witchweeds. Plant Cell Physiol 2023; 64:936-954. [PMID: 37319019 PMCID: PMC10504575 DOI: 10.1093/pcp/pcad058] [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: 05/11/2023] [Revised: 06/05/2023] [Accepted: 06/14/2023] [Indexed: 06/17/2023]
Abstract
Root parasitic plants of the Orobanchaceae, broomrapes and witchweeds, pose a severe problem to agriculture in Europe, Asia and especially Africa. These parasites are totally dependent on their host for survival, and therefore, their germination is tightly regulated by host presence. Indeed, their seeds remain dormant in the soil until a host root is detected through compounds called germination stimulants. Strigolactones (SLs) are the most important class of germination stimulants. They play an important role in planta as a phytohormone and, upon exudation from the root, function in the recruitment of symbiotic arbuscular mycorrhizal fungi. Plants exude mixtures of various different SLs, possibly to evade detection by these parasites and still recruit symbionts. Vice versa, parasitic plants must only respond to the SL composition that is exuded by their host, or else risk germination in the presence of non-hosts. Therefore, parasitic plants have evolved an entire clade of SL receptors, called HTL/KAI2s, to perceive the SL cues. It has been demonstrated that these receptors each have a distinct sensitivity and specificity to the different known SLs, which possibly allows them to recognize the SL-blend characteristic of their host. In this review, we will discuss the molecular basis of SL sensitivity and specificity in these parasitic plants through HTL/KAI2s and review the evidence that these receptors contribute to host specificity of parasitic plants.
Collapse
Affiliation(s)
- Sjors Huizinga
- Plant Hormone Biology Group, Green Life Sciences Cluster, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| | - Harro J Bouwmeester
- Plant Hormone Biology Group, Green Life Sciences Cluster, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, Amsterdam 1098 XH, The Netherlands
| |
Collapse
|
2
|
Mallu TS, Irafasha G, Mutinda S, Owuor E, Githiri SM, Odeny DA, Runo S. Mechanisms of pre-attachment Striga resistance in sorghum through genome-wide association studies. Mol Genet Genomics 2022; 297:751-762. [PMID: 35305146 DOI: 10.1007/s00438-022-01882-6] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 02/26/2022] [Indexed: 11/30/2022]
Abstract
Witchweeds (Striga spp.) greatly limit production of Africa's most staple crops. These parasitic plants use strigolactones (SLs)-chemical germination stimulants, emitted from host's roots to germinate, and locate their hosts for invasion. This information exchange provides opportunities for controlling the parasite by either stimulating parasite seed germination without a host (suicidal germination) or by inhibiting parasite seed germination (pre-attachment resistance). We sought to determine genetic factors that underpin Striga pre-attachment resistance in sorghum using the genome wide association study (GWAS) approach. Results revealed that Striga germination was associated with genes encoding hormone signaling functions, e.g., the Novel interactor of jaz (NINJA) and, Abscisic acid-insensitive 5 (ABI5). This pointed toward abscisic acid (ABA) and gibberellic acid (GA) as probable determinants of Striga germination. To test this hypothesis, we conditioned Striga using: ABA, ABA + its inhibitor fluridone (FLU), GA or water. Unexpectedly, Striga conditioned with FLU germinated after 4 days without SL. Upon germination stimulation using sorghum root exudate or the synthetic SL GR24, we found that ABA conditioned seeds had above 20-fold reduction in germination. Conversely, FLU conditioned seeds recorded above 20-fold increase in germination. Conditioning with GA reduced Striga seed germination 1.5-fold only in the GR24 treatment. Germination assays using seeds of a related parasitic plant (Alectra vogelii) showed similar degrees of stimulation and reduction of germination by the hormones further affirming the hormonal crosstalk. Our findings have far-reaching implications in the control of some of the most noxious pathogens of crops in Africa.
Collapse
Affiliation(s)
- Tesfamichael S Mallu
- Pan African University Institute for Basic Sciences, Technology and Innovation, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya.,Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya
| | - Gilles Irafasha
- Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya
| | - Sylvia Mutinda
- Pan African University Institute for Basic Sciences, Technology and Innovation, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya.,Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya
| | - Erick Owuor
- International Crops Research Institute for the Semi-Arid Tropics, P. O. Box 39063-00623, Nairobi, Kenya
| | - Stephen M Githiri
- Department of Horticulture and Food Security, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya
| | - Damaris A Odeny
- International Crops Research Institute for the Semi-Arid Tropics, P. O. Box 39063-00623, Nairobi, Kenya.
| | - Steven Runo
- Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya.
| |
Collapse
|
3
|
Kawa D, Taylor T, Thiombiano B, Musa Z, Vahldick HE, Walmsley A, Bucksch A, Bouwmeester H, Brady SM. Characterization of growth and development of sorghum genotypes with differential susceptibility to Striga hermonthica. J Exp Bot 2021; 72:7970-7983. [PMID: 34410382 PMCID: PMC8643648 DOI: 10.1093/jxb/erab380] [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] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Two sorghum varieties, Shanqui Red (SQR) and SRN39, have distinct levels of susceptibility to the parasitic weed Striga hermonthica, which have been attributed to different strigolactone composition within their root exudates. Root exudates of the Striga-susceptible variety Shanqui Red (SQR) contain primarily 5-deoxystrigol, which has a high efficiency for inducing Striga germination. SRN39 roots primarily exude orobanchol, leading to reduced Striga germination and making this variety resistant to Striga. The structural diversity in exuded strigolactones is determined by a polymorphism in the LOW GERMINATION STIMULANT 1 (LGS1) locus. Yet, the genetic diversity between SQR and SRN39 is broad and has not been addressed in terms of growth and development. Here, we demonstrate additional differences between SQR and SRN39 by phenotypic and molecular characterization. A suite of genes related to metabolism was differentially expressed between SQR and SRN39. Increased levels of gibberellin precursors in SRN39 were accompanied by slower growth rate and developmental delay and we observed an overall increased SRN39 biomass. The slow-down in growth and differences in transcriptome profiles of SRN39 were strongly associated with plant age. Additionally, enhanced lateral root growth was observed in SRN39 and three additional genotypes exuding primarily orobanchol. In summary, we demonstrate that the differences between SQR and SRN39 reach further than the changes in strigolactone profile in the root exudate and translate into alterations in growth and development.
Collapse
Affiliation(s)
- Dorota Kawa
- Department of Plant Biology and Genome Center, University of California, Davis, Davis, CA, USA
| | - Tamera Taylor
- Department of Plant Biology and Genome Center, University of California, Davis, Davis, CA, USA
- Plant Biology Graduate Group, University of California, Davis, Davis, CA, USA
| | - Benjamin Thiombiano
- Plant Hormone Biology Group, Green Life Sciences Cluster, Swammerdam Institute for Life Science, University of Amsterdam, Amsterdam, the Netherlands
| | - Zayan Musa
- Department of Plant Biology and Genome Center, University of California, Davis, Davis, CA, USA
| | - Hannah E Vahldick
- Department of Plant Biology and Genome Center, University of California, Davis, Davis, CA, USA
| | - Aimee Walmsley
- Plant Hormone Biology Group, Green Life Sciences Cluster, Swammerdam Institute for Life Science, University of Amsterdam, Amsterdam, the Netherlands
| | - Alexander Bucksch
- Department of Plant Biology, University of Georgia, Athens, GA, USA
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
- Warnell School of Forestry and Natural Resources, University of Georgia, GA, USA
| | - Harro Bouwmeester
- Plant Hormone Biology Group, Green Life Sciences Cluster, Swammerdam Institute for Life Science, University of Amsterdam, Amsterdam, the Netherlands
| | - Siobhan M Brady
- Department of Plant Biology and Genome Center, University of California, Davis, Davis, CA, USA
| |
Collapse
|
4
|
Yoda A, Mori N, Akiyama K, Kikuchi M, Xie X, Miura K, Yoneyama K, Sato‐Izawa K, Yamaguchi S, Yoneyama K, Nelson DC, Nomura T. Strigolactone biosynthesis catalyzed by cytochrome P450 and sulfotransferase in sorghum. New Phytol 2021; 232:1999-2010. [PMID: 34525227 PMCID: PMC9292024 DOI: 10.1111/nph.17737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 03/01/2021] [Accepted: 09/05/2021] [Indexed: 05/19/2023]
Abstract
Root parasitic plants such as Striga, Orobanche, and Phelipanche spp. cause serious damage to crop production world-wide. Deletion of the Low Germination Stimulant 1 (LGS1) gene gives a Striga-resistance trait in sorghum (Sorghum bicolor). The LGS1 gene encodes a sulfotransferase-like protein, but its function has not been elucidated. Since the profile of strigolactones (SLs) that induce seed germination in root parasitic plants is altered in the lgs1 mutant, LGS1 is thought to be an SL biosynthetic enzyme. In order to clarify the enzymatic function of LGS1, we looked for candidate SL substrates that accumulate in the lgs1 mutants and performed in vivo and in vitro metabolism experiments. We found the SL precursor 18-hydroxycarlactonoic acid (18-OH-CLA) is a substrate for LGS1. CYP711A cytochrome P450 enzymes (SbMAX1 proteins) in sorghum produce 18-OH-CLA. When LGS1 and SbMAX1 coding sequences were co-expressed in Nicotiana benthamiana with the upstream SL biosynthesis genes from sorghum, the canonical SLs 5-deoxystrigol and 4-deoxyorobanchol were produced. This finding showed that LGS1 in sorghum uses a sulfo group to catalyze leaving of a hydroxyl group and cyclization of 18-OH-CLA. A similar SL biosynthetic pathway has not been found in other plant species.
Collapse
Affiliation(s)
- Akiyoshi Yoda
- Department of Biological Production ScienceUnited Graduate School of Agricultural ScienceTokyo University of Agriculture and TechnologyTokyo183‐8509Japan
- Center for Bioscience Research and EducationUtsunomiya UniversityTochigi321‐8505Japan
| | - Narumi Mori
- Department of Applied Life SciencesGraduate School of Life and Environmental SciencesOsaka Prefecture UniversityOsaka599‐8531Japan
| | - Kohki Akiyama
- Department of Applied Life SciencesGraduate School of Life and Environmental SciencesOsaka Prefecture UniversityOsaka599‐8531Japan
| | - Mayu Kikuchi
- Center for Bioscience Research and EducationUtsunomiya UniversityTochigi321‐8505Japan
| | - Xiaonan Xie
- Department of Biological Production ScienceUnited Graduate School of Agricultural ScienceTokyo University of Agriculture and TechnologyTokyo183‐8509Japan
- Center for Bioscience Research and EducationUtsunomiya UniversityTochigi321‐8505Japan
| | - Kenji Miura
- Graduate School of Life and Environmental SciencesUniversity of TsukubaTsukuba305‐8572Japan
| | - Kaori Yoneyama
- Graduate School of AgricultureEhime UniversityEhime790‐8566Japan
- Japan Science and Technology AgencyPRESTOSaitama332‐0012Japan
| | - Kanna Sato‐Izawa
- Department of BioscienceFaculty of Life SciencesTokyo University of AgricultureTokyo156‐8502Japan
| | | | - Koichi Yoneyama
- Center for Bioscience Research and EducationUtsunomiya UniversityTochigi321‐8505Japan
- Women’s Future Development CenterEhime UniversityEhime790‐8566Japan
| | - David C. Nelson
- Department of Botany & Plant SciencesUniversity of CaliforniaRiversideCA92521USA
| | - Takahito Nomura
- Department of Biological Production ScienceUnited Graduate School of Agricultural ScienceTokyo University of Agriculture and TechnologyTokyo183‐8509Japan
- Center for Bioscience Research and EducationUtsunomiya UniversityTochigi321‐8505Japan
| |
Collapse
|
5
|
Fishman MR, Shirasu K. How to resist parasitic plants: pre- and post-attachment strategies. Curr Opin Plant Biol 2021; 62:102004. [PMID: 33647828 DOI: 10.1016/j.pbi.2021.102004] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Abstract
The lifecycle of parasitic plants can be divided into pre-attachment and post-attachment phases that equate to free living and parasitic stages. Similarly, plant resistance to parasitic plants can be defined as pre-attachment and post-attachment resistance. Parasitic plants rely on host cues for successful host invasion. During pre-attachment resistance, changes in the composition of host signals can disrupt parasitic plant development and ultimately host invasion. Recent studies have only now begun to elucidate the genetic elements in the host that promote pre-attachment resistance. In comparison, new research points to post-attachment resistance using the common molecular mechanisms utilized by the plant immune system during plant-pathogen interactions. In kind, parasitic plants secrete proteinaceous and RNA-based effectors post-attachment to subvert the host immune system.
Collapse
Affiliation(s)
| | - Ken Shirasu
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan; Graduate School of Science, The University of Tokyo, Tokyo, Japan.
| |
Collapse
|
6
|
Zagorchev L, Stöggl W, Teofanova D, Li J, Kranner I. Plant Parasites under Pressure: Effects of Abiotic Stress on the Interactions between Parasitic Plants and Their Hosts. Int J Mol Sci 2021; 22:7418. [PMID: 34299036 PMCID: PMC8304456 DOI: 10.3390/ijms22147418] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/02/2021] [Accepted: 07/08/2021] [Indexed: 01/07/2023] Open
Abstract
Parasitic angiosperms, comprising a diverse group of flowering plants, are partially or fully dependent on their hosts to acquire water, mineral nutrients and organic compounds. Some have detrimental effects on agriculturally important crop plants. They are also intriguing model systems to study adaptive mechanisms required for the transition from an autotrophic to a heterotrophic metabolism. No less than any other plant, parasitic plants are affected by abiotic stress factors such as drought and changes in temperature, saline soils or contamination with metals or herbicides. These effects may be attributed to the direct influence of the stress, but also to diminished host availability and suitability. Although several studies on abiotic stress response of parasitic plants are available, still little is known about how abiotic factors affect host preferences, defense mechanisms of both hosts and parasites and the effects of combinations of abiotic and biotic stress experienced by the host plants. The latter effects are of specific interest as parasitic plants pose additional pressure on contemporary agriculture in times of climate change. This review summarizes the existing literature on abiotic stress response of parasitic plants, highlighting knowledge gaps and discussing perspectives for future research and potential agricultural applications.
Collapse
Affiliation(s)
- Lyuben Zagorchev
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China;
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria;
| | - Wolfgang Stöggl
- Department of Botany and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria; (W.S.); (I.K.)
| | - Denitsa Teofanova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria;
| | - Junmin Li
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China;
| | - Ilse Kranner
- Department of Botany and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria; (W.S.); (I.K.)
| |
Collapse
|
7
|
Mallu TS, Mutinda S, Githiri SM, Achieng Odeny D, Runo S. New pre-attachment Striga resistant sorghum adapted to African agro-ecologies. Pest Manag Sci 2021; 77:2894-2902. [PMID: 33576100 DOI: 10.1002/ps.6325] [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: 09/02/2020] [Revised: 01/23/2021] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Pre-attachment resistance to the parasitic plants Striga hermonthica and S. asiatica occurs in sorghum mutants designated low germination stimulant 1 (lgs1). However, only a few of these mutants have been identified and their resistance validated. Additionally, pre-attachment resistance in sorghum beyond lgs1 mutants has not been explored. We used lgs1-specific markers to identify new lgs1-like mutants in a diverse global sorghum collection. The sorghum collection was also evaluated for pre-attachment resistance against Striga using an in vitro assay that measured Striga germination activity and radicle growth. RESULTS From a total of 177 sorghum accessions, 60 recorded mean germination levels of below 42%, which is comparable with the previously identified lgs1-like sorghum (SRN39 and IS9830) used as controls in this study. Furthermore, 32 of these accessions recorded Striga radicle lengths comparable or lower than the controls (0.42 mm). Thirty-eight accessions contained the lgs1 mutation and although overall, lgs1 mutants had considerably reduced Striga germination, some low inducers of Striga germination were wild-type for lgs1. Germination was positively but weakly correlated with radicle length pointing to additional radicle growth inhibitory activity. CONCLUSIONS lgs1 mutations, alongside other mechanisms for low Striga germination stimulation, are prevalent in sorghum, and poor Striga radicle growth is suggestive of host-derived inhibition. As an outcome, our study makes available multiple Striga-resistant sorghum with adaptability to diverse agro-ecological regions in sub-Saharan Africa making immediate deployment possible. © 2021 Society of Chemical Industry.
Collapse
Affiliation(s)
- Tesfamichael S Mallu
- Pan African University, Institute for Basic Sciences, Technology and Innovation, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Sylvia Mutinda
- Pan African University, Institute for Basic Sciences, Technology and Innovation, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Stephen M Githiri
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Damaris Achieng Odeny
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) - Eastern and Southern Africa, Nairobi, Kenya
| | - Steven Runo
- Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, Nairobi, Kenya
| |
Collapse
|
8
|
Mwangangi IM, Büchi L, Haefele SM, Bastiaans L, Runo S, Rodenburg J. Combining host plant defence with targeted nutrition: key to durable control of hemiparasitic Striga in cereals in sub-Saharan Africa? New Phytol 2021; 230:2164-2178. [PMID: 33577098 DOI: 10.1111/nph.17271] [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: 12/02/2020] [Accepted: 02/07/2021] [Indexed: 06/12/2023]
Abstract
Host plant defence mechanisms (resistance and tolerance) and plant nutrition are two of the most widely proposed components for the control of hemiparasitic weeds of the genus Striga in tropical cereal production systems. Neither of the two components alone is effective enough to prevent parasitism and concomitant crop losses. This review explores the potential of improved plant nutrition, being the chemical constituent of soil fertility, to fortify the expression of plant inherent resistance and tolerance against Striga. Beyond reviewing advances in parasitic plant research, we assess relevant insights from phytopathology and plant physiology in the broader sense to identify opportunities and knowledge gaps and to develop the way forward regarding research and development of combining genetics and plant nutrition for the durable control of Striga.
Collapse
Affiliation(s)
- Immaculate M Mwangangi
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, ME4 4TB, UK
| | - Lucie Büchi
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, ME4 4TB, UK
| | - Stephan M Haefele
- Sustainable Agriculture Sciences Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Lammert Bastiaans
- Centre for Crop Systems Analysis, Wageningen University & Research, Wageningen, 6700 AK, the Netherlands
| | - Steven Runo
- Department of Biochemistry, Microbiology and Biotechnology, Kenyatta University, Nairobi, 43844-0100, Kenya
| | - Jonne Rodenburg
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent, ME4 4TB, UK
| |
Collapse
|
9
|
Bouwmeester H, Li C, Thiombiano B, Rahimi M, Dong L. Adaptation of the parasitic plant lifecycle: germination is controlled by essential host signaling molecules. Plant Physiol 2021; 185:1292-1308. [PMID: 33793901 PMCID: PMC8133609 DOI: 10.1093/plphys/kiaa066] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/12/2020] [Indexed: 05/25/2023]
Abstract
Parasitic plants are plants that connect with a haustorium to the vasculature of another, host, plant from which they absorb water, assimilates, and nutrients. Because of this parasitic lifestyle, parasitic plants need to coordinate their lifecycle with that of their host. Parasitic plants have evolved a number of host detection/host response mechanisms of which the germination in response to chemical host signals in one of the major families of parasitic plants, the Orobanchaceae, is a striking example. In this update review, we discuss these germination stimulants. We review the different compound classes that function as germination stimulants, how they are produced, and in which host plants. We discuss why they are reliable signals, how parasitic plants have evolved mechanisms that detect and respond to them, and whether they play a role in host specificity. The advances in the knowledge underlying this signaling relationship between host and parasitic plant have greatly improved our understanding of the evolution of plant parasitism and are facilitating the development of more effective control measures in cases where these parasitic plants have developed into weeds.
Collapse
Affiliation(s)
- Harro Bouwmeester
- Plant Hormone Biology group, Green Life Sciences cluster, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Changsheng Li
- Plant Hormone Biology group, Green Life Sciences cluster, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Benjamin Thiombiano
- Plant Hormone Biology group, Green Life Sciences cluster, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Mehran Rahimi
- Plant Hormone Biology group, Green Life Sciences cluster, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Lemeng Dong
- Plant Hormone Biology group, Green Life Sciences cluster, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| |
Collapse
|
10
|
Abstract
The Striga, particularly S. he rmonthica, problem has become a major threat to food security, exacerbating hunger and poverty in many African countries. A number of Striga control strategies have been proposed and tested during the past decade, however, further research efforts are still needed to provide sustainable and effective solutions to the Striga problem. In this paper, we provide an update on the recent progress and the approaches used in Striga management, and highlight emerging opportunities for developing new technologies to control this enigmatic parasite.
Collapse
Affiliation(s)
- Muhammad Jamil
- Division of Biological and Environmental Sciences and Engineering, the BioActives Lab, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Boubacar A Kountche
- Division of Biological and Environmental Sciences and Engineering, the BioActives Lab, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Salim Al-Babili
- Division of Biological and Environmental Sciences and Engineering, the BioActives Lab, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
- Author for communication:
| |
Collapse
|
11
|
Wakabayashi T, Ishiwa S, Shida K, Motonami N, Suzuki H, Takikawa H, Mizutani M, Sugimoto Y. Identification and characterization of sorgomol synthase in sorghum strigolactone biosynthesis. Plant Physiol 2021; 185:902-913. [PMID: 33793911 PMCID: PMC8133691 DOI: 10.1093/plphys/kiaa113] [Citation(s) in RCA: 5] [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: 06/26/2020] [Accepted: 12/09/2020] [Indexed: 05/10/2023]
Abstract
Strigolactones (SLs), first identified as germination stimulants for root parasitic weeds, act as endogenous phytohormones regulating shoot branching and as root-derived signal molecules mediating symbiotic communications in the rhizosphere. Canonical SLs typically have an ABCD ring system and can be classified into orobanchol- and strigol-type based on the C-ring stereochemistry. Their simplest structures are 4-deoxyorobanchol (4DO) and 5-deoxystrigol (5DS), respectively. Diverse canonical SLs are chemically modified with one or more hydroxy or acetoxy groups introduced into the A- and/or B-ring of these simplest structures, but the biochemical mechanisms behind this structural diversity remain largely unexplored. Sorgomol in sorghum (Sorghum bicolor [L.] Moench) is a strigol-type SL with a hydroxy group at C-9 of 5DS. In this study, we characterized sorgomol synthase. Microsomal fractions prepared from a high-sorgomol-producing cultivar of sorghum, Sudax, were shown to convert 5DS to sorgomol. A comparative transcriptome analysis identified SbCYP728B subfamily as candidate genes encoding sorgomol synthase. Recombinant SbCYP728B35 catalyzed the conversion of 5DS to sorgomol in vitro. Substrate specificity revealed that the C-8bS configuration in the C-ring of 5DS stereoisomers was essential for this reaction. The overexpression of SbCYP728B35 in Lotus japonicus hairy roots, which produce 5DS as an endogenous SL, also resulted in the conversion of 5DS to sorgomol. Furthermore, SbCYP728B35 expression was not detected in nonsorgomol-producing cultivar, Abu70, suggesting that this gene is responsible for sorgomol production in sorghum. Identification of the mechanism modifying parental 5DS of strigol-type SLs provides insights on how plants biosynthesize diverse SLs.
Collapse
Affiliation(s)
- Takatoshi Wakabayashi
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Shunsuke Ishiwa
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Kasumi Shida
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Noriko Motonami
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Hideyuki Suzuki
- Kazusa DNA Research Institute, Kazusa-kamatari 2-6-7, Kisarazu, Chiba, 292-0818, Japan
| | - Hirosato Takikawa
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Masaharu Mizutani
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Yukihiro Sugimoto
- Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
- Author for communication:
| |
Collapse
|
12
|
de Oliveira IF, Simeone MLF, de Guimarães CC, Garcia NS, Schaffert RE, de Sousa SM. Sorgoleone concentration influences mycorrhizal colonization in sorghum. Mycorrhiza 2021; 31:259-264. [PMID: 33200347 DOI: 10.1007/s00572-020-01006-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 07/07/2020] [Accepted: 11/11/2020] [Indexed: 06/11/2023]
Abstract
The association between arbuscular mycorrhizal fungi (AMF) and sorghum, the fifth most cultivated cereal in the world and a staple food for many countries, is relevant to improving phosphorus (P) absorption. The importance of root exudation as a signal for the symbiosis has been shown for several species, but a complete understanding of the signaling molecules involved in the mycorrhizal symbiosis signaling pathway has not yet been elucidated. In this context, we investigated the effect of sorgoleone, one of the most studied allelochemicals and a predominant compound of root exudates in sorghum, on AMF colonization and consequently P uptake and plant growth on a sorghum genotype. The sorghum genotype P9401 presents low endogenous sorgoleone content, and when it was inoculated with Rhizophagus clarus together with 5 and 10 µM sorgoleone, mycorrhizal colonization was enhanced. A significant enhancement of mycorrhizal colonization and an increase of P content and biomass were observed when R. clarus was inoculated together with 20 µM sorgoleone. Thus, our results indicate that sorgoleone influences mycorrhizal colonization, but the mechanisms by which it does so still need to be revealed.
Collapse
Affiliation(s)
- Isabela Figueiredo de Oliveira
- Universidade Federal de São João del-Rei, R. Padre João Pimentel, 80, Dom Bosco, São João del-Rei, Minas Gerais, 36301-158, Brazil
| | - Maria Lúcia Ferreira Simeone
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Milho e Sorgo, Rod. MG 424 KM 65, Sete Lagoas, Minas Gerais, 35701-970, Brazil
| | - Cristiane Carvalho de Guimarães
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Milho e Sorgo, Rod. MG 424 KM 65, Sete Lagoas, Minas Gerais, 35701-970, Brazil
| | - Nathally Stefany Garcia
- Universidade Federal de São João del-Rei, Rod. MG 424 KM 47, Sete Lagoas, Minas Gerais, 35701-970, Brazil
| | - Robert Eugene Schaffert
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Milho e Sorgo, Rod. MG 424 KM 65, Sete Lagoas, Minas Gerais, 35701-970, Brazil
| | - Sylvia Morais de Sousa
- Universidade Federal de São João del-Rei, R. Padre João Pimentel, 80, Dom Bosco, São João del-Rei, Minas Gerais, 36301-158, Brazil.
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Milho e Sorgo, Rod. MG 424 KM 65, Sete Lagoas, Minas Gerais, 35701-970, Brazil.
| |
Collapse
|
13
|
Chesterfield RJ, Vickers CE, Beveridge CA. Translation of Strigolactones from Plant Hormone to Agriculture: Achievements, Future Perspectives, and Challenges. Trends Plant Sci 2020; 25:1087-1106. [PMID: 32660772 DOI: 10.1016/j.tplants.2020.06.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [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: 03/27/2020] [Revised: 06/04/2020] [Accepted: 06/10/2020] [Indexed: 05/21/2023]
Abstract
Strigolactones (SLs) control plant development, enhance symbioses, and act as germination stimulants for some of the most destructive species of parasitic weeds, making SLs a potential tool to improve crop productivity and resilience. Field trials demonstrate the potential use of SLs as agrochemicals or genetic targets in breeding programs, with applications in improving drought tolerance, increasing yields, and controlling parasitic weeds. However, for effective translation of SLs into agriculture, understanding and exploiting SL diversity and the development of economically viable sources of SL analogs will be critical. Here we review how manipulation of SL signaling can be used when developing new tools and crop varieties to address some critical challenges, such as nutrient acquisition, resource allocation, stress tolerance, and plant-parasite interactions.
Collapse
Affiliation(s)
- Rebecca J Chesterfield
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia; Synthetic Biology Future Science Platform, CSIRO, Australia
| | - Claudia E Vickers
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia; Synthetic Biology Future Science Platform, CSIRO, Australia.
| | - Christine A Beveridge
- School of Biological Sciences, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
| |
Collapse
|
14
|
Floková K, Shimels M, Andreo Jimenez B, Bardaro N, Strnad M, Novák O, Bouwmeester HJ. An improved strategy to analyse strigolactones in complex sample matrices using UHPLC-MS/MS. Plant Methods 2020; 16:125. [PMID: 32963580 PMCID: PMC7499983 DOI: 10.1186/s13007-020-00669-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 09/08/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND Strigolactones represent the most recently described group of plant hormones involved in many aspects of plant growth regulation. Simultaneously, root exuded strigolactones mediate rhizosphere signaling towards beneficial arbuscular mycorrhizal fungi, but also attract parasitic plants. The seed germination of parasitic plants induced by host strigolactones leads to serious agricultural problems worldwide. More insight in these signaling molecules is hampered by their extremely low concentrations in complex soil and plant tissue matrices, as well as their instability. So far, the combination of tailored isolation-that would replace current unspecific, time-consuming and labour-intensive processing of large samples-and a highly sensitive method for the simultaneous profiling of a broad spectrum of strigolactones has not been reported. RESULTS Depending on the sample matrix, two different strategies for the rapid extraction of the seven structurally similar strigolactones and highly efficient single-step pre-concentration on polymeric RP SPE sorbent were developed and validated. Compared to conventional methods, controlled temperature during the extraction and the addition of an organic modifier (acetonitrile, acetone) to the extraction solvent helped to tailor strigolactone isolation from low initial amounts of root tissue (150 mg fresh weight, FW) and root exudate (20 ml), which improved both strigolactone stability and sample purity. We have designed an efficient UHPLC separation with sensitive MS/MS detection for simultaneous analysis of seven natural strigolactones including their biosynthetic precursors-carlactone and carlactonoic acid. In combination with the optimized UHPLC-MS/MS method, attomolar detection limits were achieved. The new method allowed successful profiling of seven strigolactones in small exudate and root tissue samples of four different agriculturally important plant species-sorghum, rice, pea and tomato. CONCLUSION The established method provides efficient strigolactone extraction with aqueous mixtures of less nucleophilic organic solvents from small root tissue and root exudate samples, in combination with rapid single-step pre-concentration. This method improves strigolactone stability and eliminates the co-extraction and signal of matrix-associated contaminants during the final UHPLC-MS/MS analysis with an electrospray interface, which dramatically increases the overall sensitivity of the analysis. We show that the method can be applied to a variety of plant species.
Collapse
Affiliation(s)
- Kristýna Floková
- Plant Hormone Biology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
- Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences, and Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Mahdere Shimels
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Department of Microbial Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands
| | - Beatriz Andreo Jimenez
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Biointeractions and Plant Health, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Nicoletta Bardaro
- Department of Plant, Soil and Food Science, Section of Genetics and Plant Breeding, University of Bari, Via Amendola 165/A, 70126 Bari, Italy
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences, and Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Ondřej Novák
- Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences, and Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Harro J. Bouwmeester
- Plant Hormone Biology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| |
Collapse
|
15
|
Bellis ES, Kelly EA, Lorts CM, Gao H, DeLeo VL, Rouhan G, Budden A, Bhaskara GB, Hu Z, Muscarella R, Timko MP, Nebie B, Runo SM, Chilcoat ND, Juenger TE, Morris GP, dePamphilis CW, Lasky JR. Genomics of sorghum local adaptation to a parasitic plant. Proc Natl Acad Sci U S A 2020; 117:4243-4251. [PMID: 32047036 PMCID: PMC7049153 DOI: 10.1073/pnas.1908707117] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Host-parasite coevolution can maintain high levels of genetic diversity in traits involved in species interactions. In many systems, host traits exploited by parasites are constrained by use in other functions, leading to complex selective pressures across space and time. Here, we study genome-wide variation in the staple crop Sorghum bicolor (L.) Moench and its association with the parasitic weed Striga hermonthica (Delile) Benth., a major constraint to food security in Africa. We hypothesize that geographic selection mosaics across gradients of parasite occurrence maintain genetic diversity in sorghum landrace resistance. Suggesting a role in local adaptation to parasite pressure, multiple independent loss-of-function alleles at sorghum LOW GERMINATION STIMULANT 1 (LGS1) are broadly distributed among African landraces and geographically associated with S. hermonthica occurrence. However, low frequency of these alleles within S. hermonthica-prone regions and their absence elsewhere implicate potential trade-offs restricting their fixation. LGS1 is thought to cause resistance by changing stereochemistry of strigolactones, hormones that control plant architecture and below-ground signaling to mycorrhizae and are required to stimulate parasite germination. Consistent with trade-offs, we find signatures of balancing selection surrounding LGS1 and other candidates from analysis of genome-wide associations with parasite distribution. Experiments with CRISPR-Cas9-edited sorghum further indicate that the benefit of LGS1-mediated resistance strongly depends on parasite genotype and abiotic environment and comes at the cost of reduced photosystem gene expression. Our study demonstrates long-term maintenance of diversity in host resistance genes across smallholder agroecosystems, providing a valuable comparison to both industrial farming systems and natural communities.
Collapse
Affiliation(s)
- Emily S Bellis
- Department of Biology, The Pennsylvania State University, University Park, PA 16802;
- Arkansas Biosciences Institute, Arkansas State University, State University, AR 72467
- Department of Computer Science, Arkansas State University, State University, AR 72467
| | - Elizabeth A Kelly
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
- Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, PA 16802
| | - Claire M Lorts
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| | - Huirong Gao
- Applied Science and Technology, Corteva Agriscience, Johnston, IA 50131
| | - Victoria L DeLeo
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
- Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, PA 16802
| | - Germinal Rouhan
- Institut Systématique Evolution Biodiversité, Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, École Pratique des Hautes Études, CP39, 75005 Paris, France
| | - Andrew Budden
- Identification & Naming, Royal Botanic Gardens, Kew, TW9 3AB Richmond, United Kingdom
| | - Govinal B Bhaskara
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712
| | - Zhenbin Hu
- Department of Agronomy, Kansas State University, Manhattan, KS 66506
| | - Robert Muscarella
- Department of Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, SE-75236 Uppsala, Sweden
| | - Michael P Timko
- Department of Biology, University of Virginia, Charlottesville, VA 22904
| | - Baloua Nebie
- West and Central Africa Regional Program, International Crops Research Institute for the Semi-Arid Tropics, BP 320 Bamako, Mali
| | - Steven M Runo
- Department of Biochemistry and Biotechnology, Kenyatta University, Nairobi, Kenya
| | - N Doane Chilcoat
- Applied Science and Technology, Corteva Agriscience, Johnston, IA 50131
| | - Thomas E Juenger
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712
| | - Geoffrey P Morris
- Department of Agronomy, Kansas State University, Manhattan, KS 66506
| | - Claude W dePamphilis
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| | - Jesse R Lasky
- Department of Biology, The Pennsylvania State University, University Park, PA 16802
| |
Collapse
|
16
|
Cox DE, Dyer S, Weir R, Cheseto X, Sturrock M, Coyne D, Torto B, Maule AG, Dalzell JJ. ABC transporter genes ABC-C6 and ABC-G33 alter plant-microbe-parasite interactions in the rhizosphere. Sci Rep 2019; 9:19899. [PMID: 31882903 PMCID: PMC6934816 DOI: 10.1038/s41598-019-56493-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 12/08/2019] [Indexed: 11/20/2022] Open
Abstract
Plants are master regulators of rhizosphere ecology, secreting a complex mixture of compounds into the soil, collectively termed plant root exudate. Root exudate composition is highly dynamic and functional, mediating economically important interactions between plants and a wide range of soil organisms. Currently we know very little about the molecular basis of root exudate composition, which is a key hurdle to functional exploitation of root exudates for crop improvement. Root expressed transporters modulate exudate composition and could be manipulated to develop beneficial plant root exudate traits. Using Virus Induced Gene silencing (VIGS), we demonstrate that knockdown of two root-expressed ABC transporter genes in tomato cv. Moneymaker, ABC-C6 and ABC-G33, alters the composition of semi-volatile compounds in collected root exudates. Root exudate chemotaxis assays demonstrate that knockdown of each transporter gene triggers the repulsion of economically relevant Meloidogyne and Globodera spp. plant parasitic nematodes, which are attracted to control treatment root exudates. Knockdown of ABC-C6 inhibits egg hatching of Meloidogyne and Globodera spp., relative to controls. Knockdown of ABC-G33 has no impact on egg hatching of Meloidogyne spp. but has a substantial inhibitory impact on egg hatching of G. pallida. ABC-C6 knockdown has no impact on the attraction of the plant pathogen Agrobacterium tumefaciens, or the plant growth promoting Bacillus subtilis, relative to controls. Silencing ABC-G33 induces a statistically significant reduction in attraction of B. subtilis, with no impact on attraction of A. tumefaciens. By inoculating selected differentially exuded compounds into control root exudates, we demonstrate that hexadecaonic acid and pentadecane are biologically relevant parasite repellents. ABC-C6 represents a promising target for breeding or biotechnology intervention strategies as gene knockdown leads to the repulsion of economically important plant parasites and retains attraction of the beneficial rhizobacterium B. subtilis. This study exposes the link between ABC transporters, root exudate composition, and ex planta interactions with agriculturally and economically relevant rhizosphere organisms, paving the way for new approaches to rhizosphere engineering and crop protection.
Collapse
Affiliation(s)
- Deborah Elizabeth Cox
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, UK
| | - Steven Dyer
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, UK
| | - Ryan Weir
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, UK
| | - Xavier Cheseto
- The International Center of Insect Physiology and Ecology, Nairobi, Kenya
| | - Matthew Sturrock
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, UK
| | - Danny Coyne
- The International Institute for Tropical Agriculture, Nairobi, Kenya
| | - Baldwyn Torto
- The International Center of Insect Physiology and Ecology, Nairobi, Kenya
| | - Aaron G Maule
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, UK
| | - Johnathan J Dalzell
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, UK.
| |
Collapse
|
17
|
Borghi L, Kang J, de Brito Francisco R. Filling the Gap: Functional Clustering of ABC Proteins for the Investigation of Hormonal Transport in planta. Front Plant Sci 2019; 10:422. [PMID: 31057565 PMCID: PMC6479136 DOI: 10.3389/fpls.2019.00422] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/20/2019] [Indexed: 05/09/2023]
Abstract
Plant hormones regulate a myriad of plant processes, from seed germination to reproduction, from complex organ development to microelement uptake. Much has been discovered on the factors regulating the activity of phytohormones, yet there are gaps in knowledge about their metabolism, signaling as well as transport. In this review we analyze the potential of the characterized phytohormonal transporters belonging to the ATP-Binding Cassette family (ABC proteins), thus to identify new candidate orthologs in model plants and species important for human health and food production. Previous attempts with phylogenetic analyses on transporters belonging to the ABC family suggested that sequence homology per se is not a powerful tool for functional characterization. However, we show here that sequence homology might indeed support functional conservation of characterized members of different classes of ABC proteins in several plant species, e.g., in the case of ABC class G transporters of strigolactones and ABC class B transporters of auxinic compounds. Also for the low-affinity, vacuolar abscisic acid (ABA) transporters belonging to the ABCC class we show that localization-, rather than functional-clustering occurs, possibly because of sequence conservation for targeting the tonoplast. The ABC proteins involved in pathogen defense are phylogenetically neighboring despite the different substrate identities, suggesting that sequence conservation might play a role in their activation/induction after pathogen attack. Last but not least, in case of the multiple lipid transporters belong to different ABC classes, we focused on ABC class D proteins, reported to transport/affect the synthesis of hormonal precursors. Based on these results, we propose that phylogenetic approaches followed by transport bioassays and in vivo investigations might accelerate the discovery of new hormonal transport routes and allow the designing of transgenic and genome editing approaches, aimed to improve our knowledge on plant development, plant-microbe symbioses, plant nutrient uptake and plant stress resistance.
Collapse
|