1
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Li GB, Liu J, He JX, Li GM, Zhao YD, Liu XL, Hu XH, Zhang X, Wu JL, Shen S, Liu XX, Zhu Y, He F, Gao H, Wang H, Zhao JH, Li Y, Huang F, Huang YY, Zhao ZX, Zhang JW, Zhou SX, Ji YP, Pu M, He M, Chen X, Wang J, Li W, Wu XJ, Ning Y, Sun W, Xu ZJ, Wang WM, Fan J. Rice false smut virulence protein subverts host chitin perception and signaling at lemma and palea for floral infection. THE PLANT CELL 2024; 36:2000-2020. [PMID: 38299379 PMCID: PMC11062437 DOI: 10.1093/plcell/koae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 02/02/2024]
Abstract
The flower-infecting fungus Ustilaginoidea virens causes rice false smut, which is a severe emerging disease threatening rice (Oryza sativa) production worldwide. False smut not only reduces yield, but more importantly produces toxins on grains, posing a great threat to food safety. U. virens invades spikelets via the gap between the 2 bracts (lemma and palea) enclosing the floret and specifically infects the stamen and pistil. Molecular mechanisms for the U. virens-rice interaction are largely unknown. Here, we demonstrate that rice flowers predominantly employ chitin-triggered immunity against U. virens in the lemma and palea, rather than in the stamen and pistil. We identify a crucial U. virens virulence factor, named UvGH18.1, which carries glycoside hydrolase activity. Mechanistically, UvGH18.1 functions by binding to and hydrolyzing immune elicitor chitin and interacting with the chitin receptor CHITIN ELICITOR BINDING PROTEIN (OsCEBiP) and co-receptor CHITIN ELICITOR RECEPTOR KINASE1 (OsCERK1) to impair their chitin-induced dimerization, suppressing host immunity exerted at the lemma and palea for gaining access to the stamen and pistil. Conversely, pretreatment on spikelets with chitin induces a defense response in the lemma and palea, promoting resistance against U. virens. Collectively, our data uncover a mechanism for a U. virens virulence factor and the critical location of the host-pathogen interaction in flowers and provide a potential strategy to control rice false smut disease.
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Affiliation(s)
- Guo-Bang Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Jie Liu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jia-Xue He
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Gao-Meng Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Ya-Dan Zhao
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiao-Ling Liu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiao-Hong Hu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- Ecological Security and Protection Key Laboratory of Sichuan Province, Mianyang Normal University, Mianyang 621023, China
| | - Xin Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jin-Long Wu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Shuai Shen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Xin-Xian Liu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Yong Zhu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Feng He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Han Gao
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - He Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jing-Hao Zhao
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Yan Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Fu Huang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Yan-Yan Huang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhi-Xue Zhao
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Ji-Wei Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Shi-Xin Zhou
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Yun-Peng Ji
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Mei Pu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Min He
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Xuewei Chen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jing Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Weitao Li
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Xian-Jun Wu
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Yuese Ning
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wenxian Sun
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Zheng-Jun Xu
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Wen-Ming Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jing Fan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- Yazhouwan National Laboratory, Sanya 572024, China
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Zhang G, Zhou X, Liu S, Ma Y, Li H, Du Y, Cao Z, Sun L. Full-length transcriptomics study of Ustiloxins-induced hepatocyte injury. Toxicon 2024; 238:107604. [PMID: 38181838 DOI: 10.1016/j.toxicon.2024.107604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/14/2023] [Accepted: 01/03/2024] [Indexed: 01/07/2024]
Abstract
Ustiloxins is a mycotoxin produced by the metabolism of Rice false smut. Studies have shown that Ustiloxins may be toxic to animals, but there is still a lack of toxicological evidence. The liver, as the main organ for the biotransformation of foreign chemicals, may be the direct target organ of Ustiloxins toxicity. In this study, we found that cell viability decreased in a dose- and time-dependent manner when BNL CL.2 cells were treated with different concentrations of Ustiloxins (0, 5, 10, 20, 30, 40, 60, 80, 100, 150 and 200 μg/mL) for 24 and 48 h. In addition, scanning electron microscope observation showed that the cell membrane of the experimental group was damaged, with the appearance of apoptotic bodies. Moreover, the ROS and GSH levels were significantly increased in cells exposed to Ustiloxins. We analyzed the key action targets of Ustiloxins on hepatocyte injury using full-length transcriptomics. A total of 1099 differentially expressed genes were screened, of which 473 genes were up-regulated, and 626 genes were down-regulated. Besides, we also found that the expression of MCM7 and CDC45 in BNL CL.2 cells treated with Ustiloxins decreased, and the expression of CCl-2, CYP1b1, CYP4f13, and GSTM1 increased according to qRT-PCR. Ustiloxins might change CYP450 and GST-related genes, affect DNA replication and cell cycle, and lead to oxidative stress and liver cell injury.
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Affiliation(s)
- Guomei Zhang
- School of Public Health (Food Science and Engineering), Hangzhou Medical College, Hangzhou, Zhejiang, 310013, China
| | - Xuming Zhou
- School of Public Health (Food Science and Engineering), Hangzhou Medical College, Hangzhou, Zhejiang, 310013, China
| | - Shanshan Liu
- School of Public Health (Food Science and Engineering), Hangzhou Medical College, Hangzhou, Zhejiang, 310013, China
| | - Youning Ma
- Rice Product Quality Inspection and Supervision Center of Ministry of Agriculture, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, China
| | - Han Li
- School of Public Health (Food Science and Engineering), Hangzhou Medical College, Hangzhou, Zhejiang, 310013, China
| | - Yingchun Du
- School of Public Health (Food Science and Engineering), Hangzhou Medical College, Hangzhou, Zhejiang, 310013, China
| | - Zhaoyun Cao
- Rice Product Quality Inspection and Supervision Center of Ministry of Agriculture, China National Rice Research Institute, Hangzhou, Zhejiang, 310006, China.
| | - Lihua Sun
- School of Public Health (Food Science and Engineering), Hangzhou Medical College, Hangzhou, Zhejiang, 310013, China.
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Fang A, Zhang R, Qiao W, Peng T, Qin Y, Wang J, Tian B, Yu Y, Sun W, Yang Y, Bi C. Sensitivity Baselines, Resistance Monitoring, and Molecular Mechanisms of the Rice False Smut Pathogen Ustilaginoidea virens to Prochloraz and Azoxystrobin in Four Regions of Southern China. J Fungi (Basel) 2023; 9:832. [PMID: 37623603 PMCID: PMC10456073 DOI: 10.3390/jof9080832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/25/2023] [Accepted: 08/04/2023] [Indexed: 08/26/2023] Open
Abstract
Rice false smut caused by Ustilaginoidea virens is one of the most devastating fungal diseases of rice (Oryza sativa) worldwide. Prochloraz and azoxystrobin belong to the groups of demethylation inhibitors and quinone outside inhibitors, respectively, and are commonly used for controlling this disease. In this study, we analyzed the sensitivities of 100 U. virens isolates from Yunnan, Sichuan, Chongqing, and Zhejiang in Southern China to prochloraz and azoxystrobin. The ranges of EC50 for prochloraz and azoxystrobin were 0.004-0.536 and 0.020-0.510 μg/mL, with means and standard errors of 0.062 ± 0.008 and 0.120 ± 0.007 μg/mL, respectively. However, the sensitivity frequency distributions of U. virens to prochloraz and azoxystrobin indicated the emergence of subpopulations with decreased sensitivity. Therefore, the mean EC50 values of 74% and 68% of the isolates at the main peak, 0.031 ± 0.001 and 0.078 ± 0.004 μg/mL, were used as the sensitivity baselines of U. virens to prochloraz and azoxystrobin, respectively. We found significant sensitivity differences to azoxystrobin among different geographical populations and no correlation between the sensitivities of U. virens to prochloraz and azoxystrobin. Among 887 U. virens isolates, the isolate 5-3-1 from Zhejiang showed moderate resistance to prochloraz, with a resistance factor of 22.45, while no nucleotide variation in the 1986-bp upstream or 1827-bp gene regions of CYP51 from 5-3-1 was detected. Overexpression of CYP51 is probably responsible for its resistance to prochloraz. Finally, artificial inoculation showed that 5-3-1 was highly pathogenic to rice, suggesting that the resistance of U. virens to prochloraz must be monitored and managed in Zhejiang.
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Affiliation(s)
- Anfei Fang
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Ruixuan Zhang
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Wei Qiao
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Tao Peng
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Yubao Qin
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Jing Wang
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Binnian Tian
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Yang Yu
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China;
| | - Yuheng Yang
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
| | - Chaowei Bi
- College of Plant Protection, Southwest University, 2 Tiansheng Rd., Beibei District, Chongqing 400715, China; (A.F.); (R.Z.); (W.Q.); (T.P.); (Y.Q.); (J.W.); (B.T.); (Y.Y.)
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4
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Khanal S, Gaire SP, Zhou XG. Kernel Smut and False Smut: The Old-Emerging Diseases of Rice-A Review. PHYTOPATHOLOGY 2023; 113:931-944. [PMID: 36441871 DOI: 10.1094/phyto-06-22-0226-rvw] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Kernel smut, caused by Tilletia horrida, is a disease characterized by the replacement of rice grains with black sooty masses of teliospores or chlamydospores. Kernel smut differs from rice false smut, caused by Ustilaginoidea virens, in the color of chlamydospores. False smut is characterized by globose, velvety spore balls ranging from orangish yellow to greenish black in color. Both kernel smut and false smut have been persistent but are considered minor diseases in many countries since they were discovered in the late 1870s to the 1980s due to their sporadic outbreaks and limited economic impacts. In recent years, however, kernel smut and false smut have emerged as two of the most economically important diseases in rice, including organic rice, in many countries, especially in the United States. The increased use of susceptible rice cultivars, especially hybrids, excessive use of nitrogen fertilizer, and short crop rotations have resulted in an increase in kernel smut and false smut, causing significant losses in grain yield and quality. In this article, we provide a review of the distribution and economic importance of kernel smut; our current understanding of the taxonomy, biology, and epidemiology of kernel smut; and the genomics of the kernel smut fungus as compared with false smut and its causal agent. We also provide an update on the current management strategies of pathogen exclusion, cultivar resistance, fungicides, biological control, and cultural practices for kernel smut and false smut of rice.
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Affiliation(s)
- Sabin Khanal
- Texas A&M AgriLife Research Center, Beaumont, TX 77713
| | | | - Xin-Gen Zhou
- Texas A&M AgriLife Research Center, Beaumont, TX 77713
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5
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Jose RC, Kanchal T, Louis B, Talukdar NC, Chowdhury D. Grain Characteristics, Moisture, and Specific Peptides Produced by Ustilaginoidea virens Contribute to False Smut Disease in Rice ( Oryza sativa L.). Biomolecules 2023; 13:biom13040669. [PMID: 37189416 DOI: 10.3390/biom13040669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/20/2023] [Accepted: 02/23/2023] [Indexed: 05/17/2023] Open
Abstract
The fungus Ustilaginoidea virens, the causative agent of false smut in rice (Oryza sativa L.), is responsible for one of the severe grain diseases that lead to significant losses worldwide. In this research, microscopic and proteomic analyses were performed by comparing U. virens infected and non-infected grains of the susceptible and resistant rice varieties to provide insights into the molecular and ultrastructural factors involved in false smut formation. Prominent differentially expressed peptide bands and spots were detected due to false smut formation as revealed by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoresis (2-DE) SDS-PAGE profiles and were identified using liquid chromatography-mass spectrometry (LC-MS/MS). The proteins identified from the resistant grains were involved in diverse biological processes such as cell redox homeostasis, energy, stress tolerance, enzymatic activities, and metabolic pathways. It was found that U. virens produces diverse degrading enzymes such as β-1, 3-endoglucanase, subtilisin-like protease, putative nuclease S1, transaldolase, putative palmitoyl-protein thioesterase, adenosine kinase, and DNase 1 that could discretely alter the host morphophysiology resulting in false smut. The fungus also produced superoxide dismutase, small secreted proteins, and peroxidases during the smut formation. This study revealed that the dimension of rice grain spikes, their elemental composition, moisture content, and the specific peptides produced by the grains and the fungi U. virens play a vital role in the formation of false smut.
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Affiliation(s)
- Robinson C Jose
- Institute of Advanced Study in Science and Technology, Guwahati 781035, India
- Institute of Bioresources and Sustainable Development (IBSD), Imphal 795001, India
| | - Thangjam Kanchal
- Institute of Bioresources and Sustainable Development (IBSD), Imphal 795001, India
| | - Bengyella Louis
- Department of Plant Sciences, University Park, Pennsylvania State University, 101 Tyson Bldg, State College, PA 16802, USA
| | - Narayan C Talukdar
- Institute of Advanced Study in Science and Technology, Guwahati 781035, India
- Faculty of Science, Assam Down Town University, Guwahati 781026, India
| | - Devasish Chowdhury
- Institute of Advanced Study in Science and Technology, Guwahati 781035, India
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Yang D, He N, Huang F, Jin Y, Li S. The Genetic Mechanism of the Immune Response to the Rice False Smut (RFS) Fungus Ustilaginoidea virens. PLANTS (BASEL, SWITZERLAND) 2023; 12:741. [PMID: 36840089 PMCID: PMC9961370 DOI: 10.3390/plants12040741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Rice false smut (RFS), which is caused by Ustilaginoidea virens (U. virens), has become one of the most devastating diseases in rice-growing regions worldwide. The disease results in a significant yield loss and poses health threats to humans and animals due to producing mycotoxins. In this review, we update the understanding of the symptoms and resistance genes of RFS, as well as the genomics and effectors in U. virens. We also highlight the genetic mechanism of the immune response to RFS. Finally, we analyse and explore the identification method for RFS, breeding for resistance against the disease, and interactions between the effector proteins and resistance (R) proteins, which would be involved in the development of rice disease resistance materials for breeding programmes.
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Affiliation(s)
- Dewei Yang
- Institute of Rice, Fujian Academy of Agricultural Sciences, Fuzhou 350018, China
| | - Niqing He
- Institute of Rice, Fujian Academy of Agricultural Sciences, Fuzhou 350018, China
| | - Fenghuang Huang
- Institute of Rice, Fujian Academy of Agricultural Sciences, Fuzhou 350018, China
| | - Yidan Jin
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shengping Li
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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7
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Yang J, Zhang N, Wang J, Fang A, Fan J, Li D, Li Y, Wang S, Cui F, Yu J, Liu Y, Wang WM, Peng YL, He SY, Sun W. SnRK1A-mediated phosphorylation of a cytosolic ATPase positively regulates rice innate immunity and is inhibited by Ustilaginoidea virens effector SCRE1. THE NEW PHYTOLOGIST 2022; 236:1422-1440. [PMID: 36068953 DOI: 10.1111/nph.18460] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Rice false smut caused by Ustilaginoidea virens is becoming one of the most recalcitrant rice diseases worldwide. However, the molecular mechanisms underlying rice immunity against U. virens remain unknown. Using genetic, biochemical and disease resistance assays, we demonstrated that the xb24 knockout lines generated in non-Xa21 rice background exhibit an enhanced susceptibility to the fungal pathogens U. virens and Magnaporthe oryzae. Consistently, flg22- and chitin-induced oxidative burst and expression of pathogenesis-related genes in the xb24 knockout lines were greatly attenuated. As a central mediator of energy signaling, SnRK1A interacts with and phosphorylates XB24 at Thr83 residue to promote ATPase activity. SnRK1A is activated by pathogen-associated molecular patterns and positively regulates plant immune responses and disease resistance. Furthermore, the virulence effector SCRE1 in U. virens targets host ATPase XB24. The interaction inhibits ATPase activity of XB24 by blocking ATP binding to XB24. Meanwhile, SCRE1 outcompetes SnRK1A for XB24 binding, and thereby suppresses SnRK1A-mediated phosphorylation and ATPase activity of XB24. Our results indicate that the conserved SnRK1A-XB24 module in multiple crop plants positively contributes to plant immunity and uncover an unidentified molecular strategy to promote infection in U. virens and a novel host target in fungal pathogenesis.
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Affiliation(s)
- Jiyun Yang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Nan Zhang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Jiyang Wang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Anfei Fang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Jing Fan
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Dayong Li
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
| | - Yuejiao Li
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Shanzhi Wang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Fuhao Cui
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
| | - Junjie Yu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, China
| | - Yongfeng Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, China
| | - Wen-Ming Wang
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - You-Liang Peng
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
- State Key Laboratory of Agricultural Biotechnology, China Agricultural University, Beijing, 100193, China
| | - Sheng Yang He
- Howard Hughes Medical Institute, Duke University, Durham, NC, 27708, USA
| | - Wenxian Sun
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100193, China
- College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
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8
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Tan Z, Bai Z, Qin Y, Du J, Zhang R, Tian B, Yang Y, Yu Y, Bi C, Sun W, Fang A. Characterization of Genetic Diversity and Variation in Pathogenicity of the Rice False Smut Pathogen Ustilaginoidea virens from a Single Source. PLANT DISEASE 2022; 106:2648-2655. [PMID: 35394330 DOI: 10.1094/pdis-11-21-2546-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Rice false smut, caused by Ustilaginoidea virens, is one of the most destructive fungal diseases in rice-growing countries. Studies of the genetic diversity, evolution, and pathogenicity of U. virens can provide more information for disease control and cultivar breeding. Contrary to previous studies on the genetic diversity of different geographical populations of U. virens, this study analyzed the genetic variation of U. virens from different panicles of the same rice cultivar in a field in Yunnan Province using single nucleotide polymorphism molecular markers. A total of 183 polymorphic loci and five haplotypes, hap_1 to hap_5, were identified based on the 1,350-bp combined DNA fragment of 127 isolates, showing some genetic diversity. Hap_1 and hap_3 had the highest occurrence, indicating they were the dominant haplotypes in the field. Further analysis showed that most rice panicles could be coinfected by different haplotypes, and even a few spikelets could be coinfected by multiple haplotypes. The phylogeny indicated that all isolates were divided into five genetic groups. Groups I, II, and III clustered together and were distinguished from Groups IV and V. Significant genetic variations in five pairwise comparisons of panicle populations, accounting for 72.45% of the total variation, were found according to FST values. This variation might be caused by different field microenvironments and the uneven distribution of inoculum sources. An unweighted pair-group method with arithmetic means dendrogram and the population structure revealed that the genetic composition of the isolates collected from YN1, YN2, and YN4, which were dominated by the same genetic subgroup, was different from that collected from YN3. Finally, genetic recombination was found in 11 isolates; hap_2 and hap_5, probably as genetic recombination progenies produced by sexual hybridization between hap_1 and hap_3, acquired a greater virulence than their ancestors according to population structure and pathogenicity analyses. These results will help us understand the genetic diversity, evolution, and infection process of U. virens and aid in the development of more effective management strategies for rice false smut, including new cultivars with improved resistance.
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Affiliation(s)
- Ze Tan
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Zhenxu Bai
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yubao Qin
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Jianhang Du
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Ruixuan Zhang
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Binnian Tian
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yuheng Yang
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yang Yu
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Chaowei Bi
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China
| | - Anfei Fang
- College of Plant Protection, Southwest University, Chongqing 400715, China
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9
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Ustilaginoidea virens Nuclear Effector SCRE4 Suppresses Rice Immunity via Inhibiting Expression of a Positive Immune Regulator OsARF17. Int J Mol Sci 2022; 23:ijms231810527. [PMID: 36142440 PMCID: PMC9501289 DOI: 10.3390/ijms231810527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/05/2022] [Accepted: 09/08/2022] [Indexed: 11/17/2022] Open
Abstract
Rice false smut caused by the biotrophic fungal pathogen Ustilaginoidea virens has become one of the most important diseases in rice. The large effector repertory in U. virens plays a crucial role in virulence. However, current knowledge of molecular mechanisms how U. virens effectors target rice immune signaling to promote infection is very limited. In this study, we identified and characterized an essential virulence effector, SCRE4 (Secreted Cysteine-Rich Effector 4), in U. virens. SCRE4 was confirmed as a secreted nuclear effector through yeast secretion, translocation assays and protein subcellular localization, as well as up-regulation during infection. The SCRE4 gene deletion attenuated the virulence of U. virens to rice. Consistently, ectopic expression of SCRE4 in rice inhibited chitin-triggered immunity and enhanced susceptibility to false smut, substantiating that SCRE4 is an essential virulence factor. Furthermore, SCRE4 transcriptionally suppressed the expression of OsARF17, an auxin response factor in rice, which positively regulates rice immune responses and resistance against U. virens. Additionally, the immunosuppressive capacity of SCRE4 depended on its nuclear localization. Therefore, we uncovered a virulence strategy in U. virens that transcriptionally suppresses the expression of the immune positive modulator OsARF17 through nucleus-localized effector SCRE4 to facilitate infection.
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10
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Fang A, Fu Z, Wang Z, Fu Y, Qin Y, Bai Z, Tan Z, Cai J, Yang Y, Yu Y, Sun W, Bi C. Genetic Diversity and Population Structure of the Rice False Smut Pathogen Ustilaginoidea virens in the Sichuan-Chongqing Region. PLANT DISEASE 2022; 106:93-100. [PMID: 34340563 DOI: 10.1094/pdis-04-21-0750-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Rice false smut caused by Ustilaginoidea virens is one of the most devastating fungal diseases of rice panicles worldwide. In this study, two novel molecular markers derived from single nucleotide polymorphism-rich genomic DNA fragments and a previously reported molecular marker were used for analyzing the genetic diversity and population structure of 167 U. virens isolates collected from nine areas in the Sichuan-Chongqing region, China. A total of 62 haplotypes were identified, and a few haplotypes with high frequency were found and distributed in two to three areas, suggesting gene flow among different geographical populations. All isolates were divided into six genetic groups. Groups I and VI were the largest, with 61 and 48 isolates, respectively. The pairwise FST values showed significant genetic differentiation among all compared geographical populations. Analysis of molecular variance showed that intergroup genetic variation accounted for 40.17% of the total genetic variation, while 59.83% of genetic variation came from intragroup genetic variation. The unweighted pair-group method with arithmetic means dendrogram and population structure revealed that the genetic composition of isolates collected from Santai, Nanchong, Yongchuan, and Wansheng dominated by the same genetic subgroup was different from those collected from other areas. In addition, genetic recombination was found in a few isolates. These findings will help to improve the strategies for rice false smut management and resistance breeding, such as evaluating breeding lines with different isolates or haplotypes at different elevations and landforms.
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Affiliation(s)
- Anfei Fang
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Zhuangyuan Fu
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Zexiong Wang
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yuhang Fu
- Sericulture Station of Chongqing, Chongqing 400020, China
| | - Yubao Qin
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Zhenxu Bai
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Ze Tan
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Junsong Cai
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yuheng Yang
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yang Yu
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China
| | - Chaowei Bi
- College of Plant Protection, Southwest University, Chongqing 400715, China
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11
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Meng S, Liu Z, Shi H, Wu Z, Qiu J, Wen H, Lin F, Tao Z, Luo C, Kou Y. UvKmt6-mediated H3K27 trimethylation is required for development, pathogenicity, and stress response in Ustilaginoidea virens. Virulence 2021; 12:2972-2988. [PMID: 34895056 PMCID: PMC8667953 DOI: 10.1080/21505594.2021.2008150] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Polycomb repressive complex 2 (PRC2) is responsible for the trimethylation of lysine 27 of histone H3 (H3K27me3)-mediated transcriptional silencing. At present, its biological roles in the devastating rice pathogenic fungus Ustilaginoidea virens remain unclear. In this study, we analyzed the function of a putative PRC2 catalytic subunit UvKmt6. The results showed that disruption of UvKMT6 resulted in reduced growth, conidiation and pathogenicity in U. virens. Furthermore, UvKmt6 is essential for establishment of H3K27me3 modification, which covers 321 genes in the genome. Deletion of UvKMT6 led to transcriptional derepression of 629 genes, 140 of which were occupied with H3K27me3 modification. Consistent with RNA-seq and ChIP-seq analysis, UvKmt6 was further confirmed to participate in the transcriptional repression of genes encoding effectors and genes associated with secondary metabolites production, such as PKSs, NRPSs and Cytochrome P450s. Notably, we found that UvKmt6 is involved in transcriptional repression of oxidative, osmotic, cell wall and nutrient starvation stresses response-related genes. From the perspective of gene expression and phenotype, in addition to the relatively conservative role in fungal development, virulence and production of secondary metabolites, we further reported that UvKmt6-mdediated H3K27me3 plays a critical role in the response to various stresses in U. virens.
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Affiliation(s)
- Shuai Meng
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China.,Hubei Key Laboratory of Plant Pathology, and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhiquan Liu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Huanbin Shi
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Zhongling Wu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Jiehua Qiu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Hui Wen
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Fucheng Lin
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China.,State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Zeng Tao
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China.,State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Chaoxi Luo
- Hubei Key Laboratory of Plant Pathology, and College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yanjun Kou
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
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12
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Neelam K, Kumar K, Kaur A, Kishore A, Kaur P, Babbar A, Kaur G, Kamboj I, Lore JS, Vikal Y, Mangat GS, Kaur R, Khanna R, Singh K. High-resolution mapping of the quantitative trait locus (QTLs) conferring resistance to false smut disease in rice. J Appl Genet 2021; 63:35-45. [PMID: 34535887 DOI: 10.1007/s13353-021-00659-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 07/30/2021] [Accepted: 08/23/2021] [Indexed: 11/26/2022]
Abstract
Rice false smut (RFS), an emerging major fungal disease worldwide caused by Ustilaginoidea virens, affects rice grain quality and yield. RFS cause 2.8-49% global yield loss depending upon disease severity and cultivars. In India, the yield loss due to RFS ranged from 2 to 75%. Identification of the genes or quantitative trait loci (QTLs) governing disease resistance would be of utmost importance towards mitigating the economic losses incurred due to RFS. Here, we report mapping of RFS resistance QTLs from a resistant breeding line RYT2668. The mapping population was evaluated for RFS resistance under the field condition in three cropping seasons 2013, 2015, and 2016. A positive correlation among infected panicle/plant, total smut ball/panicle, and disease score was observed in the years 2013, 2015, and the mean data. A total of seven QTLs were mapped on rice chromosomes 2, 4, 5, 7, and 9 using 2326 single nucleotide polymorphism markers. Of these, two QTLs, qRFSr5.3 and qRFSr7.1a, were associated with the infected panicle per plant, one QTL qRFsr9.1 with total smut ball per panicle, and four QTLs qRFSr2.2, qRFSr4.3, qRFSr5.4, and qRFSr7.1b with disease score. Among them, a novel QTL qRFSr9.1 on chromosome 9 exhibits the largest phenotypic effect. The prediction of putative candidate genes within the qRFSr9.1 revealed four nucleotide-binding sites-leucine-rich repeat (NBS-LRR) domain-containing disease resistance proteins. In summary, our findings mark the hotspot region of rice chromosomes carrying genes/QTLs for resistance to the RFS disease.
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Affiliation(s)
- Kumari Neelam
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab, 141004, India.
| | - Kishor Kumar
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
- Faculty Centre for Integrated Rural Development and Management, Ramakrishna Mission Vivekananda Educational and Research Institute, Narendrapur, Kolkata, 700103, India
| | - Amandeep Kaur
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Amit Kishore
- AccuScript Consultancy, Ludhiana, Punjab, 141004, India
| | - Pavneet Kaur
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Ankita Babbar
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Gurwinder Kaur
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Ishwinder Kamboj
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Jagjeet Singh Lore
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Yogesh Vikal
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - G S Mangat
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Rupinder Kaur
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Renu Khanna
- Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
| | - Kuldeep Singh
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, Punjab, 141004, India
- ICAR-National Bureau of Plant Genetic Resources, New Delhi, 110073, India
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13
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Detection of Ustiloxin A in urine by ultra-high-performance liquid chromatography-tandem mass spectrometry coupled with two-step solid-phase extraction. J Chromatogr B Analyt Technol Biomed Life Sci 2021; 1181:122916. [PMID: 34500402 DOI: 10.1016/j.jchromb.2021.122916] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 08/19/2021] [Accepted: 08/25/2021] [Indexed: 11/22/2022]
Abstract
Due to global outbreak of rice false smut disease, ustiloxin A (UA) was detected in rice. However, accurate methods for monitoring UA in human body fluids were lacking. In this context, a UPLC-MS/MS method based on two-step SPE was constructed for measuring UA in urine. The limits of UA quantification in human and mice urine were 58.3 and 108.7 ng/L, respectively. The proposed method was applied to detect UA in urine samples collected from human and mice. After dietary exposure, the contents of UA in mice urine were from 6.03 to 16.76 μg/g of creatine, accounting for approximate 14% of daily intake dose. Furthermore, due to the trace residues in rice (78-109 ng/kg), no detectable UA was observed in the urine of 20 volunteers. To the best of our knowledge, it is the first time to report the occurrence of UA in mammal urine.
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14
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Song T, Zhang Y, Zhang Q, Zhang X, Shen D, Yu J, Yu M, Pan X, Cao H, Yong M, Qi Z, Du Y, Zhang R, Yin X, Qiao J, Liu Y, Liu W, Sun W, Zhang Z, Wang Y, Dou D, Ma Z, Liu Y. The N-terminus of an Ustilaginoidea virens Ser-Thr-rich glycosylphosphatidylinositol-anchored protein elicits plant immunity as a MAMP. Nat Commun 2021; 12:2451. [PMID: 33907187 PMCID: PMC8079714 DOI: 10.1038/s41467-021-22660-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/16/2021] [Indexed: 11/22/2022] Open
Abstract
Many pathogens infect hosts through specific organs, such as Ustilaginoidea virens, which infects rice panicles. Here, we show that a microbe-associated molecular pattern (MAMP), Ser-Thr-rich Glycosyl-phosphatidyl-inositol-anchored protein (SGP1) from U. virens, induces immune responses in rice leaves but not panicles. SGP1 is widely distributed among fungi and acts as a proteinaceous, thermostable elicitor of BAK1-dependent defense responses in N. benthamiana. Plants specifically recognize a 22 amino acid peptide (SGP1 N terminus peptide 22, SNP22) in its N-terminus that induces cell death, oxidative burst, and defense-related gene expression. Exposure to SNP22 enhances rice immunity signaling and resistance to infection by multiple fungal and bacterial pathogens. Interestingly, while SGP1 can activate immune responses in leaves, SGP1 is required for U. virens infection of rice panicles in vivo, showing it contributes to the virulence of a panicle adapted pathogen. Ustilaginoidea virens is a fungal pathogen that infects rice via the panicles. Here, the authors show that U. virens SGP1, a conserved Ser-Thr-rich glycosyl-phosphatidyl-inositol-anchored protein, elicits immune responses in rice leaves while contributing to virulence in panicles.
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Affiliation(s)
- Tianqiao Song
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - You Zhang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Qi Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Xiong Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Danyu Shen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Junjie Yu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Mina Yu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xiayan Pan
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Huijuan Cao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Mingli Yong
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Zhongqiang Qi
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yan Du
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Rongsheng Zhang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xiaole Yin
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Junqing Qiao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Youzhou Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Wende Liu
- State Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, Changchun, China
| | - Zhengguang Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Daolong Dou
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Zhenchuan Ma
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China.
| | - Yongfeng Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China.
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15
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Sharanabasav H, Pramesh D, Prasannakumar MK, Chidanandappa E, Yadav MK, Ngangkham U, Parivallal B, Raghavendra BT, Manjunatha C, Sharma SK, Karthik N. Morpho-molecular and mating-type locus diversity of Ustilaginoidea virens: an incitant of false smut of rice from Southern parts of India. J Appl Microbiol 2021; 131:2372-2386. [PMID: 33772985 DOI: 10.1111/jam.15087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/17/2021] [Accepted: 03/21/2021] [Indexed: 11/30/2022]
Abstract
AIMS To characterize the geo-distinct isolates of Ustilaginoidea virens for morpho-molecular and mating-type locus diversity. METHODS AND RESULTS Sixty-one isolates of U. virens collected from Southern India exhibited significant diversity in mycelial width (3·45-5·50 µm), colony colour (yellow, pale yellow, and white), and growth pattern (thick leather mat, raised-fluffy, flat-fluffy, and raised). Field-borne chlamydospores of each isolate were significantly smaller in size (3·34-5·26 µm2 ) compared to those formed on culture media (18·6-100·89 µm2 ). The phylogenetic study based on internal transcribed sequences revealed two clusters; however, most isolates (n = 54) were grouped in cluster-I, indicating common ancestral origin. We also identified 42 haplotypes; among them, Hap_3 has the highest number of isolates (n = 19). Mating-type locus (MAT1) analysis revealed all sixty-one isolates as heterothallic, wherein 37 and 24 isolates belonging to MAT1-1-1 and MAT1-2-1 heterothallic mating types, respectively. The microsynteny analysis of MAT1 loci of one of the Indian strain (Uv-Gvt) along with Uv-8b (China) strain revealed synteny conservation at MAT1 locus, which is flanked by conserved genes SLA2 and a hypothetical protein in the upstream and APN2, COX12 and APC5 in the downstream of the locus. CONCLUSIONS Morpho-molecular study revealed the significant diversity among geo-distinct isolates, and MAT1 loci analysis indicated the distribution of heterothallic mating types in south Indian paddy fields. And also, complete synteny conservation between Indian and Chinese strain was observed at the MAT1 locus. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first report describing the sexuality of Indian strains of the U. virens, which would help better understand the genetic diversity of the U. virens prevailing in Southern India and aid in developing resistant rice cultivars against this pathogen population.
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Affiliation(s)
- H Sharanabasav
- Rice Pathology Laboratory, All India Coordinated Rice Improvement Programme, University of Agricultural Sciences, Raichur, India
| | - D Pramesh
- Rice Pathology Laboratory, All India Coordinated Rice Improvement Programme, University of Agricultural Sciences, Raichur, India
| | - M K Prasannakumar
- Department of Plant Pathology, University of Agricultural Sciences, Bangalore, India
| | - E Chidanandappa
- Rice Pathology Laboratory, All India Coordinated Rice Improvement Programme, University of Agricultural Sciences, Raichur, India
| | - M K Yadav
- ICAR-National Rice Research Institute, Cuttack, India
| | - U Ngangkham
- ICAR-Research Complex for NEH Region Umia, Meghalaya, India
| | - B Parivallal
- Department of Plant Pathology, University of Agricultural Sciences, Bangalore, India
| | - B T Raghavendra
- Department of Plant Pathology, University of Agricultural Sciences, Raichur, India
| | - C Manjunatha
- ICAR-Indian Agricultural Research Institute, Regional Station, Wellington, India
| | - S K Sharma
- ICAR-Research Complex for NEH Region, Imphal Center, Manipur, India
| | - N Karthik
- University of Madras, Chennai, India
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16
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Sun W, Fan J, Fang A, Li Y, Tariqjaveed M, Li D, Hu D, Wang WM. Ustilaginoidea virens: Insights into an Emerging Rice Pathogen. ANNUAL REVIEW OF PHYTOPATHOLOGY 2020; 58:363-385. [PMID: 32364825 DOI: 10.1146/annurev-phyto-010820-012908] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
False smut of rice, caused by Ustilaginoidea virens, has become one of the most important diseases in rice-growing regions worldwide. The disease causes a significant yield loss and imposes health threats to humans and animals by producing mycotoxins. In this review, we update our understanding of the pathogen, including the disease cycle and infection strategies, the decoding of the U. virens genome, comparative/functional genomics, and effector biology. Whereas the decoding of the U. virens genome unveils specific adaptations of the pathogen in successfully occupying rice flowers, progresses in comparative/functional genomics and effector biology have begun to uncover the molecular mechanisms underlying U. virens virulence and pathogenicity. We highlight the identification and characterization of the produced mycotoxins and their biosynthetic pathways in U. virens.The management strategies for this disease are also discussed. The flower-specific infection strategy makes the pathogen a unique tool to unveil novel mechanisms for the interactions between nonobligate biotrophic pathogens and their hosts.
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Affiliation(s)
- Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China;
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Jing Fan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China;
| | - Anfei Fang
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yuejiao Li
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Muhammad Tariqjaveed
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Dayong Li
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China;
| | - Dongwei Hu
- State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China
| | - Wen-Ming Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China;
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17
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Pramesh D, Prasannakumar MK, Muniraju KM, Mahesh HB, Pushpa HD, Manjunatha C, Saddamhusen A, Chidanandappa E, Yadav MK, Kumara MK, Sharanabasav H, Rohith BS, Banerjee G, Das AJ. Comparative genomics of rice false smut fungi Ustilaginoidea virens Uv-Gvt strain from India reveals genetic diversity and phylogenetic divergence. 3 Biotech 2020; 10:342. [PMID: 32714737 DOI: 10.1007/s13205-020-02336-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 07/12/2020] [Indexed: 12/30/2022] Open
Abstract
False smut disease of rice caused by Ustilaginoidea virens, is an emerging threat to rice cultivation worldwide due to its detrimental effects on grain yield and quality. False smut disease severity was 4.44‒17.22% during a roving survey in Kharif 2016 in the four different rice ecosystems of Karnataka, India. Further, 15 pathogen isolates representing four different ecosystems were studied for their virulence and morphometric diversity. Among the 15 strains studied, most virulent strains Uv-Gvt was selected for whole genome sequencing in Illumina NextSeq 500 platform using 2 × 150 bp sequencing chemistry. The total assembled genome of Uv-Gvt was 26.96 Mb, which comprised of 9157 scaffolds with an N50 value of 15,934 bp and 6628 protein-coding genes. Next, the comparative genomic study revealed a similar gene inventory as UV-8b and MAFF 236576 strains reported from China and Japan, respectively. But, 1756 genes were unique to Uv-Gvt strain. The Uv-Gvt genome harbors 422 putative host-pathogen interacting genes compared to 359 and 520 genes in UV-8b and MAFF 236576 strains, respectively. The variant analysis revealed low genetic diversity (0.073‒0.088%) among U. virens strains. Further, phylogenetic analysis using 250 single copy orthologs genes of U. virens revealed a distinct phylogeny and an approximate divergence time. Our study, report the genomic resource of rice false smut pathogen from India, where the disease originated, and this information will have broader applicability in understanding the pathogen population diversity.
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Affiliation(s)
- Devanna Pramesh
- Rice Pathology Laboratory, All India Co-ordinated Rice Improvement Program, Gangavathi, University of Agricultural Sciences, Raichur, 584 104 India
| | | | - Kondarajanahally M Muniraju
- Rice Pathology Laboratory, All India Co-ordinated Rice Improvement Program, Gangavathi, University of Agricultural Sciences, Raichur, 584 104 India
| | - H B Mahesh
- University of Agricultural Sciences, Bangalore, 560 065 India
| | - H D Pushpa
- ICAR-Indian Institute of Oilseed Research, Hyderabad, 500 030 India
| | - Channappa Manjunatha
- ICAR-Indian Agricultural Research Institute, Regional Station, Wellington, 643 231 India
| | - Alase Saddamhusen
- Rice Pathology Laboratory, All India Co-ordinated Rice Improvement Program, Gangavathi, University of Agricultural Sciences, Raichur, 584 104 India
| | - E Chidanandappa
- Rice Pathology Laboratory, All India Co-ordinated Rice Improvement Program, Gangavathi, University of Agricultural Sciences, Raichur, 584 104 India
| | - Manoj K Yadav
- ICAR- National Rice Research Institute, Cuttack, 753 006 India
| | - Masalavada K Kumara
- Rice Pathology Laboratory, All India Co-ordinated Rice Improvement Program, Gangavathi, University of Agricultural Sciences, Raichur, 584 104 India
| | - Huded Sharanabasav
- Rice Pathology Laboratory, All India Co-ordinated Rice Improvement Program, Gangavathi, University of Agricultural Sciences, Raichur, 584 104 India
| | - B S Rohith
- Molsys Pvt. Ltd., Bangalore, 560 064 India
| | | | - Anupam J Das
- School of Biotechnology, REVA University, Bangalore, 560 064 India
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18
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Zhang N, Yang J, Fang A, Wang J, Li D, Li Y, Wang S, Cui F, Yu J, Liu Y, Peng Y, Sun W. The essential effector SCRE1 in Ustilaginoidea virens suppresses rice immunity via a small peptide region. MOLECULAR PLANT PATHOLOGY 2020; 21:445-459. [PMID: 32087618 PMCID: PMC7060142 DOI: 10.1111/mpp.12894] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The biotrophic fungal pathogen Ustilaginoidea virens causes rice false smut, a newly emerging plant disease that has become epidemic worldwide in recent years. The U. virens genome encodes many putative effector proteins that, based on the study of other pathosystems, could play an essential role in fungal virulence. However, few studies have been reported on virulence functions of individual U. virens effectors. Here, we report our identification and characterization of the secreted cysteine-rich protein SCRE1, which is an essential virulence effector in U. virens. When SCRE1 was heterologously expressed in Magnaporthe oryzae, the protein was secreted and translocated into plant cells during infection. SCRE1 suppresses the immunity-associated hypersensitive response in the nonhost plant Nicotiana benthamiana. Induced expression of SCRE1 in rice also inhibits pattern-triggered immunity and enhances disease susceptibility to rice bacterial and fungal pathogens. The immunosuppressive activity is localized to a small peptide region that contains an important 'cysteine-proline-alanine-arginine-serine' motif. Furthermore, the scre1 knockout mutant generated using the CRISPR/Cas9 system is attenuated in U. virens virulence to rice, which is greatly complemented by the full-length SCRE1 gene. Collectively, this study indicates that the effector SCRE1 is able to inhibit host immunity and is required for full virulence of U. virens.
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Affiliation(s)
- Nan Zhang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Jiyun Yang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Anfei Fang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Jiyang Wang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Dayong Li
- College of Plant ProtectionJilin Agricultural UniversityChangchun130118China
| | - Yuejiao Li
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Shanzhi Wang
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Fuhao Cui
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Junjie Yu
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjing, Jiangsu210014China
| | - Yongfeng Liu
- Institute of Plant ProtectionJiangsu Academy of Agricultural SciencesNanjing, Jiangsu210014China
| | - You‐Liang Peng
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
- State Key Laboratory of Agricultural BiotechnologyChina Agricultural UniversityBeijing100193China
| | - Wenxian Sun
- Department of Plant Pathology and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
- College of Plant ProtectionJilin Agricultural UniversityChangchun130118China
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19
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Wang Y, Wang F, Xie S, Liu Y, Qu J, Huang J, Yin W, Luo C. Development of rice conidiation media for Ustilaginoidea virens. PLoS One 2019; 14:e0217667. [PMID: 31647810 PMCID: PMC6812814 DOI: 10.1371/journal.pone.0217667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/14/2019] [Indexed: 12/03/2022] Open
Abstract
Rice false smut, caused by the ascomycete Ustilaginoidea virens, is a serious disease of rice worldwide. Conidia are very important infectious propagules of U. virens, but the ability of pathogenic isolates to produce conidia frequently decreases in culture, which influences pathogenicity testing. Here, we developed tissue media with rice leaves or panicles that stimulate conidiation of U. virens. Among the tested media, 0.10 g/ml panicle medium was most efficient for conidiation. Whereas, some rice leaf media more effectively increased conidiation than panicle media except 0.10 g/ml panicle medium, and certain non-filtered tissue media were better than their filtered counterparts. Although the conidia induced in rice tissue media were smaller, they were able to germinate on potato sucrose agar medium and infect rice normally. The rice tissue medium is also workable in inducing conidia for conidiation-defective isolates. This method provides a foundation for the production of conidia by U. virens that will be widely applicable in pathogenicity testing as well as in genetic analyses for false smut resistance in rice cultivars.
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Affiliation(s)
- Yufu Wang
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Fei Wang
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Songlin Xie
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Yi Liu
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Jinsong Qu
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Junbin Huang
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Weixiao Yin
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
- * E-mail:
| | - Chaoxi Luo
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
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20
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Cheng S, Liu H, Sun Q, Kong R, Letcher RJ, Liu C. Occurrence of the fungus mycotoxin, ustiloxin A, in surface waters of paddy fields in Enshi, Hubei, China, and toxicity in Tetrahymena thermophila. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 251:901-909. [PMID: 31234256 DOI: 10.1016/j.envpol.2019.05.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/02/2019] [Accepted: 05/07/2019] [Indexed: 05/22/2023]
Abstract
There has been an increasing incidence rate of rice false smut in global rice cultivation areas. However, there is a dearth of studies on the environmental concentrations and hazards of ustiloxin A (UA), which is the major mycotoxin produced by a pathogenic fungus of the rice false smut. Here, the concentrations of UA in the surface waters of two paddy fields located in Enshi city, Hubei province, China, were measured, and its toxicity in T. Thermophila was evaluated. This is the first study to detect UA in the surface waters of the two paddy fields, and the measured mean concentrations were 2.82 and 0.26 μg/L, respectively. Exposure to 2.19, 19.01 or 187.13 μg/L UA for 5 days significantly reduced the theoretical population and cell size of T. thermophila. Furthermore, treatment with 187.13 μg/L UA changed the percentages of T. thermophila cells in different cell-cycle stages, and with an increased malformation rate compared with the control, suggesting the disruption of the cell cycle. The expressions of 30 genes involved in the enriched proteasome pathway, 7 cyclin genes (cyc9, cyc10, cyc16, cyc22, cyc23, cyc26, cyc33) and 2 histone genes (mlh1 and hho1) were significantly down-regulated, which might be the modes of action responsible for the disruption of cell cycling due to UA exposure.
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Affiliation(s)
- Shiyang Cheng
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Hao Liu
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Qian Sun
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Ren Kong
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Drive, Ottawa, K1A 0H3, Canada
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
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21
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Zheng J, Liu T, Guo Z, Zhang L, Mao L, Zhang Y, Jiang H. Fumigation and contact activities of 18 plant essential oils on Villosiclava virens, the pathogenic fungus of rice false smut. Sci Rep 2019; 9:7330. [PMID: 31089151 PMCID: PMC6517416 DOI: 10.1038/s41598-019-43433-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 04/23/2019] [Indexed: 11/08/2022] Open
Abstract
Rice false smut (RFS), caused by Villosiclava virens, is an emerging devastating disease of rice panicles worldwide and produces yield loss and mycotoxin residues in rice. In this study, 18 plant essential oils (PEOs) were selected to evaluate antifungal activity via fumigation and contact methods against the mycelial growth and conidial germination of V. virens. The primary compositions of PEOs with stronger fungistatic activity were analyzed using gas chromatography (GC)-mass spectrometry (MS), and the changes in the mycelial morphology were observed using scanning electron microscopy (SEM). Antifungal tests showed that cinnamon bark oil and cinnamon oil had stronger fumigation and contact effects on V. virens than the other oils tested. The primary active composition in both cinnamon bark oil and cinnamon oil was trans-cinnamaldehyde, which exhibited contact activities with EC50 values of 2.13 and 35.9 μg/mL against mycelial growth and conidial germination, respectively. The hyphae surface morphological alterations caused by cinnamon bark oil, cinnamon oil and trans-cinnamaldehyde included shriveling, vacuolation and exfoliation. In conclusion, cinnamon bark oil and cinnamon oil have the potential to prevent and control RFS, and trans-cinnamaldehyde is a promising natural lead compound for new fungicide discoveries to control RFS contamination and mycotoxin residues in rice.
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Affiliation(s)
- Jingge Zheng
- Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Tingting Liu
- Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Zhixin Guo
- Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Lan Zhang
- Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Liangang Mao
- Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yanning Zhang
- Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Hongyun Jiang
- Key Laboratory of Control of Biological Hazard Factors (Plant Origin) for Agri-product Quality and Safety, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Institute of Plant protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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22
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Fang A, Gao H, Zhang N, Zheng X, Qiu S, Li Y, Zhou S, Cui F, Sun W. A Novel Effector Gene SCRE2 Contributes to Full Virulence of Ustilaginoidea virens to Rice. Front Microbiol 2019; 10:845. [PMID: 31105658 PMCID: PMC6492501 DOI: 10.3389/fmicb.2019.00845] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 04/02/2019] [Indexed: 12/13/2022] Open
Abstract
Ustilaginoidea virens, the causal agent of rice false smut (RFS), has become one of the most devastating rice pathogens worldwide. As a group of essential virulence factors, the effectors in the filamentous fungus might play central roles in the interaction between plants and pathogens. However, little is known about the roles of individual effectors in U. virens virulence. In this study, we identified and characterized a small secreted cysteine-rich effector, SCRE2, in U. virens. SCRE2 was first confirmed as an effector through yeast secretion, protein localization and translocation assays, as well as its expression pattern during U. virens infection. Transient expression of SCRE2 in Nicotiana benthamiana suppressed necrosis-like defense symptoms triggered by the mammalian BAX and oomycete elicitin INF1 proteins. The ability of SCRE2 to inhibit immunity-associated responses in N. benthamiana, including elicitor-triggered cell death and oxidative burst, is further defined to a small peptide region SCRE268-85 through expressing a series of truncated proteins. Convincingly, ectopic expression of SCRE2 in the transgenic rice cells significantly inhibited pathogen-associated molecular pattern-triggered immunity including flg22- and chitin-induced defense gene expression and oxidative burst. Furthermore, the scre2 knockout mutant generated by the CRISPR/Cas9 system greatly attenuated in U. virens virulence to rice. Collectively, this study indicates that the effector SCRE2 is able to inhibit plant immunity and is required for full virulence of U. virens.
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Affiliation(s)
- Anfei Fang
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China.,College of Plant Protection, Southwest University, Chongqing, China
| | - Han Gao
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China
| | - Nan Zhang
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China
| | - Xinhang Zheng
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China
| | - Shanshan Qiu
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yuejiao Li
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China
| | - Shuang Zhou
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China
| | - Fuhao Cui
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China
| | - Wenxian Sun
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Plant Protection, China Agricultural University, Beijing, China.,College of Plant Protection, Jilin Agricultural University, Changchun, China
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23
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Xie S, Wang Y, Wei W, Li C, Liu Y, Qu J, Meng Q, Lin Y, Yin W, Yang Y, Luo C. The Bax inhibitor UvBI-1, a negative regulator of mycelial growth and conidiation, mediates stress response and is critical for pathogenicity of the rice false smut fungus Ustilaginoidea virens. Curr Genet 2019; 65:1185-1197. [PMID: 30993412 DOI: 10.1007/s00294-019-00970-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 04/04/2019] [Accepted: 04/06/2019] [Indexed: 01/31/2023]
Abstract
Bax inhibitor-1 (BI-1), an evolutionarily conserved protein, is a suppressor of cell death induced by the proapoptotic protein Bax and is involved in the response to biotic and abiotic stress in animals, plants and yeast. Rice false smut caused by Ustilaginoidea virens is one of the destructive rice diseases worldwide. Although BI-1 proteins are widely distributed across filamentous fungi, few of them are functionally characterized. In this study, we identified a BI-1 protein in U. virens, UvBI-1, which contains a predicted Bax inhibitor-1-like family domain and could suppress the cell death induced by Bax. By co-transformation of the CRISPR/Cas9 construct along with donor DNA fragment containing the hygromycin resistance gene, we successfully generated Uvbi-1 deletion mutants. The UvBI-1 deletion showed an increase in mycelia vegetative growth and conidiation, suggesting this gene acts as a negative regulator of the growth and conidiation. In addition, the Uvbi-1 mutants exhibited higher sensitivity to osmotic and salt stress, hydrogen peroxide stress, and cell wall or membrane stress than the wild-type strain. Furthermore, UvBI-1 deletion was found to cause increased production of secondary metabolites and loss of pathogenicity of U. virens. Taken together, our results demonstrate that UvBI-1 plays a negative role in mycelial growth and conidiation, and is critical for stress tolerance, cell wall integrity, secondary metabolites production and pathogenicity of U. virens. Therefore, this study provides new evidence on the conserved function of BI-1 among fungal organisms and other species.
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Affiliation(s)
- Songlin Xie
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yufu Wang
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wei Wei
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chongyang Li
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yi Liu
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jinsong Qu
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qianghong Meng
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yang Lin
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
| | - Weixiao Yin
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Yinong Yang
- Department of Plant Pathology and Environmental Microbiology, Huck Institute of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Chaoxi Luo
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, China
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24
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Lin X, Bian Y, Mou R, Cao Z, Cao Z, Zhu Z, Chen M. Isolation, identification, and characterization of Ustilaginoidea virens from rice false smut balls with high ustilotoxin production potential. J Basic Microbiol 2018; 58:670-678. [PMID: 29897133 DOI: 10.1002/jobm.201800167] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/09/2018] [Accepted: 05/31/2018] [Indexed: 11/10/2022]
Abstract
Ustilaginoidea (U.) virens grows on rice grains and leads to significant rice yield losses in most of the major rice producing areas. Meanwhile, ustiloxins produced by U. virens are a serious hazard to human health and ecological safety of farmlands. The other key point is that ustiloxins have been regarded as a novel resource with their potential in the treatment of cancers. There is no better way to extract ustiloxins than from pure culture of the high ustilotoxin-producing strains. U. virens has become a key research organism. However, due to the presence of some interference components, it is a certain difficulty in the successful isolation of the strain from the false smut balls. We present here a detailed study based on the separation, screening and identification of high ustiloxins-producing strains of U. virens. Through this study, we got a satisfactory success rate of separation and provided a good solution to the problem of separation. At the same time, this study provides quality resources for researchers interested in ustiloxins as anticancer agents.
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Affiliation(s)
- Xiaoyan Lin
- China National Rice Research Institute, Hangzhou, China.,Laboratory of Quality & Safety Risk Assessment for Rice (Hangzhou), Ministry of Agriculture, Hangzhou, China
| | - Yingfang Bian
- China National Rice Research Institute, Hangzhou, China.,Laboratory of Quality & Safety Risk Assessment for Rice (Hangzhou), Ministry of Agriculture, Hangzhou, China.,Shandong Product Quality Inspection Research Institute, Jinan, China
| | - Renxiang Mou
- China National Rice Research Institute, Hangzhou, China.,Laboratory of Quality & Safety Risk Assessment for Rice (Hangzhou), Ministry of Agriculture, Hangzhou, China
| | - Zhaoyun Cao
- China National Rice Research Institute, Hangzhou, China.,Laboratory of Quality & Safety Risk Assessment for Rice (Hangzhou), Ministry of Agriculture, Hangzhou, China
| | - Zhenzhen Cao
- China National Rice Research Institute, Hangzhou, China.,Laboratory of Quality & Safety Risk Assessment for Rice (Hangzhou), Ministry of Agriculture, Hangzhou, China
| | - Zhiwei Zhu
- China National Rice Research Institute, Hangzhou, China.,Laboratory of Quality & Safety Risk Assessment for Rice (Hangzhou), Ministry of Agriculture, Hangzhou, China
| | - Mingxue Chen
- China National Rice Research Institute, Hangzhou, China.,Laboratory of Quality & Safety Risk Assessment for Rice (Hangzhou), Ministry of Agriculture, Hangzhou, China
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25
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26
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Yong M, Liu Y, Chen T, Fan L, Wang Z, Hu D. Cytological studies on the infection of rice root by Ustilaginoidea virens. Microsc Res Tech 2018; 81:389-396. [PMID: 29356275 DOI: 10.1002/jemt.22990] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 11/11/2017] [Accepted: 12/28/2017] [Indexed: 11/08/2022]
Abstract
In recent years, false smut disease of rice has been one of the most important diseases of cultivated rice in China. Ustilaginoidea virens is an ascomycete fungal pathogen that causes false smut in rice. There is always controversy about whether the pathogen can infect the rice root and cause the occurrence of false smut, mainly due to lack direct cytological evidence. In our study, we observed the cytological structure of rice root invaded by U. virens. The results showed that U. virens could attach to the surface of young roots and penetrate into the intercellular space of the root epidermis. The cellulose microfibrils in root epidermal cell wall are very loose and soft, and their structural features are similar to filaments of rice. After the fungus infected the roots, a large number of fungal secretions were accumulated outside of the cell walls. At 40 days, the fungus began to degrade, but pathogens still had not infected the sclerenchyma, in which the cells are arranged densely and the cell walls are thicker. U. virens could not cross the sclerenchyma layer into the endodermis and phloem of the root. To some extent, the U. virens infection affected the leaf and root growth of the rice. After inoculation, there was no fungal mycelium found in transverse sections of the rice young stem. These results suggested that root colonization of U. virens does not lead to systemic invasion in rice.
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Affiliation(s)
- Mingli Yong
- Department of Plant Pathology, The State Kay Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yijia Liu
- Department of Plant Pathology, The State Kay Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Tianqi Chen
- Department of Plant Pathology, The State Kay Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Linlin Fan
- Department of Plant Pathology, The State Kay Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Zhengyi Wang
- Department of Plant Pathology, The State Kay Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Dongwei Hu
- Department of Plant Pathology, The State Kay Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
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27
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Yin W, Cui P, Wei W, Lin Y, Luo C. Genome-wide identification and analysis of the basic leucine zipper (bZIP) transcription factor gene family in Ustilaginoidea virens. Genome 2017; 60:1051-1059. [DOI: 10.1139/gen-2017-0089] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The basic leucine zipper (bZIP) transcription factor (TF) family is one of the largest and most diverse TF families widely distributed across the eukaryotes. The bZIP TF family plays an important role in growth, development, and response to abiotic or biotic stresses, which have been well characterized in plants, but not in plant pathogenic fungi. In this study, we performed genome-wide and systematic bioinformatics analysis of bZIP genes in the fungus Ustilaginoidea virens, the causal agent of rice false smut disease. We identified 28 bZIP family members in the U. virens genome by searching for the bZIP domain in predicted genes. The gene structures, motifs, and phylogenetic relationships were analyzed for bZIP genes in U. virens (UvbZIP). Together with bZIP proteins from two other fungi, the bZIP genes can be divided into eight groups according to their phylogenetic relationships. Based on RNA-Seq data, the expression profiles of UvbZIP genes at different infection stages were evaluated. Results showed that 17 UvbZIP genes were up-regulated during the infection period. Furthermore, 11 infection-related UvbZIP genes were investigated under H2O2 stress and the expression level of eight genes were changed, which confirmed their role in stress tolerance and pathogenicity. In summary, our genome-wide systematic characterization and expression analysis of UvbZIP genes provided insight into the molecular function of these genes in U. virens and provides a reference for other pathogens.
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Affiliation(s)
- Weixiao Yin
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Peng Cui
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Wei Wei
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Yang Lin
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
| | - Chaoxi Luo
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
- Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China
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Lv B, Zheng L, Liu H, Tang J, Hsiang T, Huang J. Use of Random T-DNA Mutagenesis in Identification of Gene UvPRO1, A Regulator of Conidiation, Stress Response, and Virulence in Ustilaginoidea virens. Front Microbiol 2016; 7:2086. [PMID: 28082958 PMCID: PMC5186764 DOI: 10.3389/fmicb.2016.02086] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 12/09/2016] [Indexed: 11/16/2022] Open
Abstract
False smut of rice, caused by Ustilaginoidea virens (Cooke) Takahashi (teleomorph: Villosiclava virens), is one of the most important diseases affecting rice worldwide. Agrobacterium tumefaciens-mediated transformation was used to identify functional genes in U. virens. In this study, we selected a single-copy insertion mutant T133 with deficiency in producing conidia by screening the T-DNA insertion mutant library of U. virens. The UvPRO1-deletion mutant was successfully obtained after cloning the targeted gene by analysis of the T-DNA insert site of mutant T133. Further research showed that the UvPRO1 mutant was reduced in growth rate and could not produce conidia in PSB medium, while sensitivities to sodium dodecyl sulfate, Congo red, and hyperosmotic stress increased. Moreover, the UvPRO1 deletion mutant hyphae could extend along the surface of spikelets at 1-3 dpi, but mycelia became shriveled and completely lost the ability to infect spikelets at 4 dpi. The relative expression level of UvPRO1 at 8 dpi was more than twice as high as that at 1-2 dpi. These results suggest that UvPRO1 plays a critical role in hyphal growth and conidiation, as well as in stress response and pathogenesis. These findings provide a novel mode of action for the PRO1 protein in fungi and improve the understanding of the function of UvPRO1 in the life cycle of U. virens.
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Affiliation(s)
- Bo Lv
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Lu Zheng
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Hao Liu
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Jintian Tang
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural UniversityWuhan, China
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, GuelphON, Canada
| | - Jinbin Huang
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural UniversityWuhan, China
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Yong ML, Fan LL, Li DY, Liu YJ, Cheng FM, Xu Y, Wang ZY, Hu DW. Villosiclava virens infects specifically rice and barley stamen filaments due to the unique host cell walls. Microsc Res Tech 2016; 79:838-44. [PMID: 27357263 DOI: 10.1002/jemt.22710] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/03/2016] [Accepted: 06/06/2016] [Indexed: 11/07/2022]
Abstract
Rice false smut, caused by the fungal pathogen Villosiclava virens, is one of the most important rice diseases in the world. Previous studies reported that the pathogen has less number of cell wall-degraded genes and attacks dominantly rice stamen filaments and extends intercellularly. To reveal why the fungus infects plant stamen filaments, inoculation test on barley was carried out with the similar protocol to rice. The experimental results showed that the fungus could penetrate quickly into barley stamen filaments and extends both intracellularly and intercellularly, usually resulting in severe damage of the stamen filament tissues. It also attacked young barley lodicules and grew intercellularly by chance. The light microscopic observations found that the epidermal and cortex cells in barley stamen filaments arranged loosely with very thick cell walls and large cell gaps. Cellulose microfibrils in barley stamen filament cell walls arranged very sparsely so that the cell walls looked like transparent. The cell walls were very soft and flexible, and often folded. However, V. virens extended dominantly in the noncellulose regions and seemed never to degrade microfibrils in barley and rice cell walls. This suggested that the unique structures of rice and barley stamen filaments should be fit for their function of elongation in anthesis, and also endow with the susceptibility to the fungus, V. virens.
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Affiliation(s)
- Ming-Li Yong
- The State Kay Laboratory for Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Lin-Lin Fan
- The State Kay Laboratory for Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Dan-Yang Li
- The State Kay Laboratory for Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Yi-Jia Liu
- The State Kay Laboratory for Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Fang-Min Cheng
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Ying Xu
- Electron Microscopy Center, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Zheng-Yi Wang
- The State Kay Laboratory for Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Dong-Wei Hu
- The State Kay Laboratory for Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China
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Fang A, Han Y, Zhang N, Zhang M, Liu L, Li S, Lu F, Sun W. Identification and Characterization of Plant Cell Death-Inducing Secreted Proteins From Ustilaginoidea virens. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:405-16. [PMID: 26927000 DOI: 10.1094/mpmi-09-15-0200-r] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Ustilaginoidea virens (Cooke) Takah (telemorph Villosiclava virens) is an ascomycetous fungus that causes rice false smut, one of the most important rice diseases. Fungal effectors often play essential roles in host-pathogen coevolutionary interactions. However, little is known about the functions of U. virens effectors. Here, we performed functional studies on putative effectors in U. virens and demonstrated that 13 of 119 putative effectors caused necrosis or necrosis-like phenotypes in Nicotiana benthamiana. Among them, 11 proteins were confirmed to be secreted, using a yeast secretion system, and the corresponding genes are all highly induced during infection, except UV_44 and UV_4753. Eight secreted proteins were proven to trigger cell death or defenses in rice protoplasts and the secretion signal of these proteins is essential for their cell death-inducing activity. The ability of UV_44 and UV_1423 to trigger cell death is dependent on the predicted serine peptidase and ribonuclease catalytic active sites, respectively. We demonstrated that UV_1423 and UV_6205 are N-glycosylated proteins, which glycosylation has different impacts on their abilities to induce cell death. Collectively, the study identified multiple secreted proteins in U. virens with specific structural motifs that induce cell death or defense machinery in nonhost and host plants.
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Affiliation(s)
- Anfei Fang
- Department of Plant Pathology; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China
| | - Yanqing Han
- Department of Plant Pathology; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China
| | - Nan Zhang
- Department of Plant Pathology; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China
| | - Min Zhang
- Department of Plant Pathology; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China
| | - Lijuan Liu
- Department of Plant Pathology; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China
| | - Shuai Li
- Department of Plant Pathology; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China
| | - Fen Lu
- Department of Plant Pathology; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China
| | - Wenxian Sun
- Department of Plant Pathology; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China
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Han Y, Zhang K, Yang J, Zhang N, Fang A, Zhang Y, Liu Y, Chen Z, Hsiang T, Sun W. Differential expression profiling of the early response to Ustilaginoidea virens between false smut resistant and susceptible rice varieties. BMC Genomics 2015; 16:955. [PMID: 26573512 PMCID: PMC4647755 DOI: 10.1186/s12864-015-2193-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 11/03/2015] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Rice false smut caused by Ustilaginoidea virens has recently become one of the most devastating rice diseases worldwide. Breeding and deployment of resistant varieties is considered as the most effective strategy to control this disease. However, little is known about the genes and molecular mechanisms underlying rice resistance against U. virens. RESULTS To explore genetic basis of rice resistance to U. virens, differential expression profiles in resistant 'IR28' and susceptible 'LYP9' cultivars during early stages of U. virens infection were compared using RNA-Seq data. The analyses revealed that 748 genes were up-regulated only in the resistant variety and 438 genes showed opposite expression patterns between the two genotypes. The genes encoding receptor-like kinases and cytoplasmic kinases were highly enriched in this pool of oppositely expressed genes. Many pathogenesis-related (PR) and diterpene phytoalexin biosynthetic genes were specifically induced in the resistant variety. Interestingly, the RY repeat motif was significantly more abundant in the 5'-regulatory regions of these differentially regulated PR genes. Several WRKY transcription factors were also differentially regulated in the two genotypes, which is consistent with our finding that the cis-regulatory W-boxes were abundant in the promoter regions of up-regulated genes in IR28. Furthermore, U. virens genes that are relevant to fungal reproduction and pathogenicity were found to be suppressed in the resistant cultivar. CONCLUSION Our results indicate that rice resistance to false smut may be attributable to plant perception of pathogen-associated molecular patterns, activation of resistance signaling pathways, induced production of PR proteins and diterpene phytoalexins, and suppression of pathogenicity genes in U. virens as well.
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Affiliation(s)
- Yanqing Han
- Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Rd., Haidian District, Beijing, 100193, China.
- Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing, 100193, China.
| | - Kang Zhang
- Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Rd., Haidian District, Beijing, 100193, China.
- Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing, 100193, China.
| | - Jun Yang
- Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Rd., Haidian District, Beijing, 100193, China.
- Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing, 100193, China.
| | - Nan Zhang
- Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Rd., Haidian District, Beijing, 100193, China.
- Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing, 100193, China.
| | - Anfei Fang
- Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Rd., Haidian District, Beijing, 100193, China.
- Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing, 100193, China.
| | - Yong Zhang
- Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Rd., Haidian District, Beijing, 100193, China.
- Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing, 100193, China.
| | - Yongfeng Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
| | - Zhiyi Chen
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, ON, N1G 2 W1, Canada.
| | - Wenxian Sun
- Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Rd., Haidian District, Beijing, 100193, China.
- Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing, 100193, China.
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Fan J, Guo XY, Li L, Huang F, Sun WX, Li Y, Huang YY, Xu YJ, Shi J, Lei Y, Zheng AP, Wang WM. Infection of Ustilaginoidea virens intercepts rice seed formation but activates grain-filling-related genes. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:577-90. [PMID: 25319482 PMCID: PMC5024071 DOI: 10.1111/jipb.12299] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 10/14/2014] [Indexed: 05/04/2023]
Abstract
Rice false smut has become an increasingly serious disease in rice (Oryza sativa L.) production worldwide. The typical feature of this disease is that the fungal pathogen Ustilaginoidea virens (Uv) specifically infects rice flower and forms false smut ball, the ustiloxin-containing ball-like fungal colony, of which the size is usually several times larger than that of a mature rice seed. However, the underlying mechanisms of Uv-rice interaction are poorly understood. Here, we applied time-course microscopic and transcriptional approaches to investigate rice responses to Uv infection. The results demonstrated that the flower-opening process and expression of associated transcription factors, including ARF6 and ARF8, were inhibited in Uv-infected spikelets. The ovaries in infected spikelets were interrupted in fertilization and thus were unable to set seeds. However, a number of grain-filling-related genes, including seed storage protein genes, starch anabolism genes and endosperm-specific transcription factors (RISBZ1 and RPBF), were highly transcribed as if the ovaries were fertilized. In addition, critical defense-related genes like NPR1 and PR1 were downregulated by Uv infection. Our data imply that Uv may hijack host nutrient reservoir by activation of the grain-filling network because of growth and formation of false smut balls.
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Affiliation(s)
- Jing Fan
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xiao-Yi Guo
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Liang Li
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Fu Huang
- College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Wen-Xian Sun
- Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Yan Li
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yan-Yan Huang
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yong-Ju Xu
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jun Shi
- College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yang Lei
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ai-Ping Zheng
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Wen-Ming Wang
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
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33
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Specific adaptation of Ustilaginoidea virens in occupying host florets revealed by comparative and functional genomics. Nat Commun 2014; 5:3849. [PMID: 24846013 DOI: 10.1038/ncomms4849] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 04/10/2014] [Indexed: 01/18/2023] Open
Abstract
Ustilaginoidea virens (Cooke) Takah is an ascomycetous fungus that causes rice false smut, a devastating emerging disease worldwide. Here we report a 39.4 Mb draft genome sequence of U. virens that encodes 8,426 predicted genes. The genome has ~25% repetitive sequences that have been affected by repeat-induced point mutations. Evolutionarily, U. virens is close to the entomopathogenic Metarhizium spp., suggesting potential host jumping across kingdoms. U. virens possesses reduced gene inventories for polysaccharide degradation, nutrient uptake and secondary metabolism, which may result from adaptations to the specific floret infection and biotrophic lifestyles. Consistent with their potential roles in pathogenicity, genes for secreted proteins and secondary metabolism and the pathogen-host interaction database genes are highly enriched in the transcriptome during early infection. We further show that 18 candidate effectors can suppress plant hypersensitive responses. Together, our analyses offer new insights into molecular mechanisms of evolution, biotrophy and pathogenesis of U. virens.
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34
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Chao J, Jin J, Wang D, Han R, Zhu R, Zhu Y, Li S. Cytological and transcriptional dynamics analysis of host plant revealed stage-specific biological processes related to compatible rice-Ustilaginoidea virens interaction. PLoS One 2014; 9:e91391. [PMID: 24646527 PMCID: PMC3960121 DOI: 10.1371/journal.pone.0091391] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/09/2014] [Indexed: 01/22/2023] Open
Abstract
Rice false smut, a fungal disease caused by Ustilaginoidea virens is becoming a severe detriment to rice production worldwide. However, little is known about the molecular response of rice to attacks by the smut pathogen. In this article, we define the initial infection process as having three stages: initial colonization on the pistil (stage 1, S1), amplification on the anther (stage 2, S2) and sporulation in the anther chambers (stage 3, S3). Based on the transcriptome of rice hosts in response to U. virens in two separate years, we identified 126, 204, and 580 specific regulated genes in their respective stages S1, S2, and S3, respectively, by excluding common expression patterns in other openly biotic/abiotic databases using bioinformatics. As the disease progresses, several stage-specific biological processes (BP) terms were distinctively enriched: "Phosphorylation" in stage S1, "PCD" in S2, and "Cell wall biogenesis" in S3, implying a concise signal cascade indicative of the tactics that smut pathogens use to control host rice cells during infection. 113 regulated genes were coexpressed among the three stages. They shared highly conserved promoter cis-element in the promoters in response to the regulation of WRKY and Myb for up-regulation, and ABA and Ca2+ for down regulation, indicating their potentially critical roles in signal transduction during rice-U. virens interaction. We further analyzed seven highly regulated unique genes; four were specific to pollen development, implying that pollen-related genes play critical roles in the establishment of rice susceptibility to U. virens. To my knowledge, this is the first report about probing of molecular response of rice to smut pathogen infection, which will greatly expand our understanding of the molecular events surrounding infection by rice false smut.
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Affiliation(s)
- Jinquan Chao
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Jie Jin
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Dong Wang
- Department of Statistics, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Ran Han
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Renshan Zhu
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Yingguo Zhu
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
| | - Shaoqing Li
- State Key Laboratory for Hybrid Rice, College of Life Science, Wuhan University, Wuhan, China
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Abbas HK, Shier WT, Cartwright RD, Sciumbato GL. <i>Ustilaginoidea virens</i> Infection of Rice in Arkansas: Toxicity of False Smut Galls, Their Extracts and the Ustiloxin Fraction. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ajps.2014.521333] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Sun X, Kang S, Zhang Y, Tan X, Yu Y, He H, Zhang X, Liu Y, Wang S, Sun W, Cai L, Li S. Genetic diversity and population structure of rice pathogen Ustilaginoidea virens in China. PLoS One 2013; 8:e76879. [PMID: 24098811 PMCID: PMC3786968 DOI: 10.1371/journal.pone.0076879] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 08/28/2013] [Indexed: 01/28/2023] Open
Abstract
Rice false smut caused by the fungal pathogen Ustilaginoidea virens is becoming a destructive disease throughout major rice-growing countries. Information about its genetic diversity and population structure is essential for rice breeding and efficient control of the disease. This study compared the genome sequences of two U. virens isolates. Three SNP-rich genomic regions were identified as molecular markers that could be used to analyze the genetic diversity and population structure of U. virens in China. A total of 56 multilocus sequence types (haplotypes) were identified out of 162 representative isolates from 15 provinces covering five major rice-growing areas in China. However, the phylogeny, based on sequences at individual SNP-rich regions, strongly conflicted with each other and there were significant genetic differences between different geographical populations. Gene flow between the different geographical populations and genetic differentiation within each geographical population were also detected. In addition, genetic recombination and genetic isolation resulting from geographic separation was also found.
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Affiliation(s)
- Xianyun Sun
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P. R. China
| | - Shu Kang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P. R. China
| | - Yongjie Zhang
- School of Life Sciences, Shanxi University, Taiyuan, P. R. China
| | - Xinqiu Tan
- Institute of Plant Protection, Hunan Academy of Agricultural Science, Changsha, P. R. China
| | - Yufei Yu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P. R. China
| | - Haiyong He
- Guizhou Institute of Plant Protection, Guiyang, P. R. China
| | - Xinyu Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P. R. China
| | - Yongfeng Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing, P. R. China
| | - Shu Wang
- Institute of Plant Protection, Liaoning Academy of Agricultural Science, Shenyang, P. R. China
| | - Wenxian Sun
- Department of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Lei Cai
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P. R. China
| | - Shaojie Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P. R. China
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37
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Zhang T, Jiang Y, Huang J, Dong W. Complete genome sequence of a putative novel victorivirus from Ustilaginoidea virens. Arch Virol 2013; 158:1403-6. [PMID: 23385326 PMCID: PMC3668124 DOI: 10.1007/s00705-013-1615-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 12/13/2012] [Indexed: 12/01/2022]
Abstract
Ustilaginoidea virens is the causal agent of a serious disease of rice. Here, we report the presence of five dsRNA bands ranging from about 1.2, 1.5, 1.7, and 1.8 to 5.6 kb in an isolate of this fungus from China and the complete sequence of the largest dsRNA segment, putatively representing the genome of a novel virus, designated as Ustilaginoidea virens RNA virus 1 (UvRV1), UvRV1, which has a genome length of 5567 bp and has two consecutive open reading frames (ORFs) with a five-nucleotide overlap. Phylogenetic analysis showed that UvRV1 belongs to the genus of Victorivirus in the family Totiviridae.
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Affiliation(s)
- Tingting Zhang
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070 Hubei, China
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38
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Li W, Li L, Feng A, Zhu X, Li J. Rice False Smut Fungus, <i>Ustilaginoidea virens</i>, Inhibits Pollen Germination and Degrades the Integuments of Rice Ovule. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ajps.2013.412284] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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39
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Fu R, Ding L, Zhu J, Li P, Zheng AP. Morphological structure of propagules and electrophoretic karyotype analysis of false smut Villosiclava virens in rice. J Microbiol 2012; 50:263-9. [DOI: 10.1007/s12275-012-1456-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 12/08/2011] [Indexed: 11/30/2022]
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40
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Brooks SA, Anders MM, Yeater KM. Influences from Long-Term Crop Rotation, Soil Tillage, and Fertility on the Severity of Rice Grain Smuts. PLANT DISEASE 2011; 95:990-996. [PMID: 30732113 DOI: 10.1094/pdis-09-10-0689] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
False smut (Ustilaginoidea virens) and kernel smut (Neovossia horrida) are diseases of rice (Oryza sativa) that reduce both grain yield and quality. Susceptible rice cultivars are in widespread use on production acreage in the United States, and the effects from crop management practices on smut control are poorly understood. We studied the long-term effects of crop rotation, soil tillage, and fertility level on rice smut severity. The highest levels of false smut observed in this study were on cultivars grown in rotation with soybean, on traditionally tilled soils, with high fertilizer treatments. The highest levels of kernel smut were observed in a rice-soybean rotation with winter wheat grown between summer crops. These rotations are commonly used in rice-growing regions of the southern United States. Using combinations of crop rotation, soil tillage, and fertility rate, several alternative crop-management practices were identified that provided effective control of smuts in susceptible rice cultivars. The most effective method for controlling both false smut and kernel smut was in 3-year rotations of rice, soybean, and corn. Regardless of rotation order or tillage and fertility treatments within the rotations, rotating out of rice for 2 years was the most effective approach for smut control.
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Affiliation(s)
- Steven A Brooks
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Stuttgart, AR 72160
| | - Merle M Anders
- University of Arkansas, Rice Research and Extension Center, Stuttgart 72160
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Brooks SA, Anders MM, Yeater KM. Effect of Furrow Irrigation on the Severity of False Smut in Susceptible Rice Varieties. PLANT DISEASE 2010; 94:570-574. [PMID: 30754472 DOI: 10.1094/pdis-94-5-0570] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
False smut (Ustilaginoidea virens) is an important emerging disease of rice (Oryza sativa) in the southern United States, where all major rice cultivars and hybrids are susceptible to the disease. False smut susceptibility was evaluated in traditional paddy-rice fields and under furrow-irrigated conditions to determine the effects of alternative agricultural practices on the severity of this disease. Highly effective false smut suppression was observed in furrow-irrigated rice, where the disease was nearly eliminated in susceptible rice entries. False smut suppression was observed for two hybrids and one conventional rice cultivar, demonstrating that suppression was not limited to specific germplasm sources. Kernel smut severity was also monitored, but no effect on this disease was observed from the irrigation treatments. Therefore, suppression of disease severity in nonflooded rice appears to be a phenomenon unique to the rice-false smut pathosystem, which can be exploited to achieve effective field resistance to this disease.
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Affiliation(s)
- Steven A Brooks
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Dale Bumpers National Rice Research Center, Stuttgart, AR 72160
| | - Merle M Anders
- University of Arkansas, Rice Research and Extension Center, Stuttgart, AR 72160
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Kim KW, Park EW. Ultrastructure of spined conidia and hyphae of the rice false smut fungus Ustilaginoidea virens. Micron 2006; 38:626-31. [PMID: 17092730 DOI: 10.1016/j.micron.2006.09.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 09/18/2006] [Accepted: 09/18/2006] [Indexed: 11/20/2022]
Abstract
Spined conidia and hyphae of Ustilaginoidea virens were examined by light and electron microscopy. Bright-field light microscopy showed that conidia were round to elliptical and warty on the surface with diameters approximately ranging from 3 to 5 microm. Scanning electron microscopy revealed the globose to irregularly rounded and ornamented conidia with prominent spines. The spines were pointed at the apex or irregularly curved, and approximately 200-500 nm long. Ultrastructure of spined conidia and hyphae revealed by transmission electron microscopy showed lipid globules and vacuoles in the cytoplasm enclosed by an electron-transparent cell wall. Conspicuous electron-dense spines were evident on the surface of conidia, and had obclavate or irregularly protruding shapes with varying heights along the conidial cell wall. Microfibrillar structures with stretching or branching patterns were evident in the spine matrix. Some conidia were interconnected by spines from the neighboring conidia by their extended outgrowth. Hyphae had concentric bodies that showed an electron-transparent core surrounded by an electron-dense layer. One or more intrahyphal hyphae were found in hyphal cytoplasm. The fungus is thought to form concentric bodies and intrahyphal hyphae as survival mechanisms against the water- and nutrient-deficient environments that may occur in the necrotic regions of host plants.
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Affiliation(s)
- Ki Woo Kim
- National Instrumentation Center for Environmental Management, Seoul National University, Seoul 151-921, Republic of Korea
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