1
|
Chandan RK, Kumar R, Swain DM, Ghosh S, Bhagat PK, Patel S, Bagler G, Sinha AK, Jha G. RAV1 family members function as transcriptional regulators and play a positive role in plant disease resistance. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:39-54. [PMID: 36703574 DOI: 10.1111/tpj.16114] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 01/14/2023] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
Phytopathogens pose a severe threat to agriculture and strengthening the plant defense response is an important strategy for disease control. Here, we report that AtRAV1, an AP2 and B3 domain-containing transcription factor, is required for basal plant defense in Arabidopsis thaliana. The atrav1 mutant lines demonstrate hyper-susceptibility against fungal pathogens (Rhizoctonia solani and Botrytis cinerea), whereas AtRAV1 overexpressing lines exhibit disease resistance against them. Enhanced expression of various defense genes and activation of mitogen-activated protein kinases (AtMPK3 and AtMPK6) are observed in the R. solani infected overexpressing lines, but not in the atrav1 mutant plants. An in vitro phosphorylation assay suggests AtRAV1 to be a novel phosphorylation target of AtMPK3. Bimolecular fluorescence complementation and yeast two-hybrid assays support physical interactions between AtRAV1 and AtMPK3. Overexpression of the native as well as phospho-mimic but not the phospho-defective variant of AtRAV1 imparts disease resistance in the atrav1 mutant A. thaliana lines. On the other hand, overexpression of AtRAV1 fails to impart disease resistance in the atmpk3 mutant. These analyses emphasize that AtMPK3-mediated phosphorylation of AtRAV1 is important for the elaboration of the defense response in A. thaliana. Considering that RAV1 homologs are conserved in diverse plant species, we propose that they can be gainfully deployed to impart disease resistance in agriculturally important crop plants. Indeed, overexpression of SlRAV1 (a member of the RAV1 family) imparts disease tolerance against not only fungal (R. solani and B. cinerea), but also against bacterial (Ralstonia solanacearum) pathogens in tomato, whereas silencing of the gene enhances disease susceptibility.
Collapse
Affiliation(s)
- Ravindra Kumar Chandan
- Plant Microbe Interactions Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
- School of Life Sciences, Central University of Gujarat, Sector-30, Gandhinagar, 382030, India
| | - Rahul Kumar
- Plant Microbe Interactions Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Durga Madhab Swain
- Plant Microbe Interactions Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Srayan Ghosh
- Plant Microbe Interactions Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Prakash Kumar Bhagat
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Sunita Patel
- School of Life Sciences, Central University of Gujarat, Sector-30, Gandhinagar, 382030, India
| | - Ganesh Bagler
- Centre for Computational Biology, Indraprastha Institute of Information Technology (IIIT-Delhi), New Delhi, 110020, India
| | - Alok Krishna Sinha
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Gopaljee Jha
- Plant Microbe Interactions Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| |
Collapse
|
2
|
Identification and expression analysis of pathogenicity-related genes of Rhizoctonia solani anastomosis groups infecting rice. 3 Biotech 2021; 11:394. [PMID: 34458063 DOI: 10.1007/s13205-021-02934-1] [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: 03/03/2021] [Accepted: 07/20/2021] [Indexed: 10/20/2022] Open
Abstract
Sheath blight disease caused by Rhizoctonia solani Kuhn (teleomorph; Thanatephorus cucumeris) is a major constraint in rice production. Among the different anastomosis groups (AGs) of Rhizoctonia solani, AG1-IA causes sheath blight of rice, which induce necrotic lesions on leaf sheaths of the infected plants. Several reports contradict the host specificity of anastomosis groups in Rhizoctonia solani. There is lack of information on the pathogenicity genes of these Rhizoctonia solani anastomosis groups during sheath blight infection in rice. In the present study, Rhizoctonia solani isolates collected from diverse rice growing regions of India were screened for anastomosis groups and two groups namely, AG1-IA, AG2-2 were identified. Accordingly, comparative studies were made with AG1-IA (GenBank ID: 16,395) and AG2-2 (GenBank ID: 2,318,768) group sequences, which enabled the identification of specific gene clusters (119 in AG1-IA and 604 in AG2-2) belonging to these groups. Pathogen Host Interaction (PHI) blast with these specific gene clusters could further identify genes involved in host pathogen interaction (38 in AG1_IA and 150 in AG2-2), which were shortlisted for qRT-PCR validation based on qcov cutoff values representing different phenotypic categories of PHI blast. Expression analysis-based validation in sheath blight susceptible (Pusa Basmati 1) and resistant (Pusa 1908-13-12-5) rice genotypes showed that most of the genes expressed significantly higher in the susceptible variety Pusa Basmati 1. The genes like inorganic phosphate transporter (AG1_IPT), Bromodomain containing protein (AG1_BrD), Aldehyde dehydrogenase (AG1_AldD), AMP binding domain (AG1_AMP) and Heme peroxidase (AG1_HmPr) were upregulated in the susceptible genotype, PB 1 at 72hpi compared to Pusa 1908-13-12-5. Among these, inorganic phosphate transporter (AG1_IPT), Bromodomain containing protein (AG1_BrD) and Heme peroxidase (AG1_HmPr) were specific to Rhizoctonia solani AG1-IA. Through the present study, we could demonstrate the AG1-IA-specific interactions of Rhizoctonia solani causing sheath blight disease of rice, which is a step forward in understanding the specificity of Rhizoctonia solani with reference to sheath blight disease of rice. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-021-02934-1.
Collapse
|
3
|
Necrotrophic lifestyle of Rhizoctonia solani AG3-PT during interaction with its host plant potato as revealed by transcriptome analysis. Sci Rep 2020; 10:12574. [PMID: 32724205 PMCID: PMC7387450 DOI: 10.1038/s41598-020-68728-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 06/24/2020] [Indexed: 12/30/2022] Open
Abstract
The soil-borne pathogen Rhizoctonia solani infects a broad range of plants worldwide and is responsible for significant crop losses. Rhizoctonia solani AG3-PT attacks germinating potato sprouts underground while molecular responses during interaction are unknown. To gain insights into processes induced in the fungus especially at early stage of interaction, transcriptional activity was compared between growth of mycelium in liquid culture and the growing fungus in interaction with potato sprouts using RNA-sequencing. Genes coding for enzymes with diverse hydrolase activities were strongly differentially expressed, however with remarkably dissimilar time response. While at 3 dpi, expression of genes coding for peptidases was predominantly induced, strongest induction was found for genes encoding hydrolases acting on cell wall components at 8 dpi. Several genes with unknown function were also differentially expressed, thus assuming putative roles as effectors to support host colonization. In summary, the presented analysis characterizes the necrotrophic lifestyle of R. solani AG3-PT during early interaction with its host.
Collapse
|
4
|
Tiwari M, Srivastava S, Singh PC, Mishra AK, Chakrabarty D. Functional characterization of tau class glutathione- S-transferase in rice to provide tolerance against sheath blight disease. 3 Biotech 2020; 10:84. [PMID: 32089979 PMCID: PMC6997320 DOI: 10.1007/s13205-020-2071-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 01/16/2020] [Indexed: 10/25/2022] Open
Abstract
Glutathione-S-transferase (GST) is an important defense gene that confers resistance against several abiotic and biotic stresses. The present study identifies a tau class GST in rice (Oryza sativa L.), OsGSTU5 (Os09g20220), which provided tolerance against sheath blight (SB) disease, caused by a necrotrophic fungus, Rhizoctonia solani (RS). Overexpression and knockdown rice transgenic lines of OsGSTU5 were generated and tested for the severity of infection during sheath blight disease. The results obtained after RS infection showed that the lesion cover area and hyphal penetration were more in knockdown line and lesser in the overexpression line. Analysis of reactive oxygen species (ROS) accumulation showed more spots of H2O2 and O2- in knockdown lines compared to overexpressed lines. Later, RS transcript level was analyzed in RS-infected transgenic lines, which manifested that the knockdown line had higher RS transcripts in comparison to the control line and least RS transcripts were observed in the overexpressed line. In conclusion, rice transgenic lines overexpressing OsGSTU5 were found to be more tolerant, while the knockdown lines were more prone to Rhizoctonia infection compared to control lines.
Collapse
Affiliation(s)
- Madhu Tiwari
- CSIR-National Botanical Research Institute, Lucknow, Uttar Pradesh India
- Banaras Hindu University, Varanasi, Uttar Pradesh India
| | - Suchi Srivastava
- CSIR-National Botanical Research Institute, Lucknow, Uttar Pradesh India
- Academy of Scientific and Innovative Research, Gaziabad, India
| | - Poonam C. Singh
- CSIR-National Botanical Research Institute, Lucknow, Uttar Pradesh India
- Academy of Scientific and Innovative Research, Gaziabad, India
| | | | - Debasis Chakrabarty
- CSIR-National Botanical Research Institute, Lucknow, Uttar Pradesh India
- Academy of Scientific and Innovative Research, Gaziabad, India
| |
Collapse
|
5
|
Monazzah M, Tahmasebi Enferadi S, Rabiei Z. Enzymatic activities and pathogenesis-related genes expression in sunflower inbred lines affected by Sclerotinia sclerotiorum culture filtrate. J Appl Microbiol 2018; 125:227-242. [PMID: 29569305 DOI: 10.1111/jam.13766] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/26/2018] [Accepted: 03/12/2018] [Indexed: 12/25/2022]
Abstract
AIMS Studying biochemical responses and pathogenesis-related gene expression in sunflower-Sclerotinia interaction can shed light on factors participating to disease resistance. METHODS AND RESULTS Partially resistant and susceptible lines were exposed to pathogen culture filtrate. The activity of antioxidant enzymes and proline was much more pronounced in partially resistant line. The more resistant to Sclerotinia sclerotiorum, the less (1,4)-β-glucanase activity was observed. PDF 1.2 and PR5-1 exhibited higher transcript abundance in the partially resistant line than in the susceptible line. CONCLUSIONS Considering the dual roles of oxalic acid, activation of the antioxidant system in partially resistant line might lead to suppression of oxidative burst which is beneficial for the growth of fungus at later stages of infection. The ability of the partially resistant line in balancing antioxidant enzymes could reserve H2 O2 as a substrate for peroxidase that might lead to lignification. The contribution of (1,4)-β-glucanase defence responses against Sclerotinia was observed. The roles of SA and JA marker genes were demonstrated in sunflower defence responses. SIGNIFICANCE AND IMPACT OF THE STUDY The time of antioxidant system activation in host is important in order to contribute to defence responses. To date, the changes in the expression of PR1 and PDF 1.2 and contribution of (1,4)-β-glucanase enzyme in sunflower defence responses were not reported in previous studies.
Collapse
Affiliation(s)
- M Monazzah
- Department of Plant Molecular Biotechnology, Institute of Agricultural Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - S Tahmasebi Enferadi
- Department of Plant Molecular Biotechnology, Institute of Agricultural Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Z Rabiei
- Department of Plant Molecular Biotechnology, Institute of Agricultural Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| |
Collapse
|
6
|
Bashyal BM, Rawat K, Sharma S, Kulshreshtha D, Gopala Krishnan S, Singh AK, Dubey H, Solanke AU, Sharma TR, Aggarwal R. Whole Genome Sequencing of Fusarium fujikuroi Provides Insight into the Role of Secretory Proteins and Cell Wall Degrading Enzymes in Causing Bakanae Disease of Rice. FRONTIERS IN PLANT SCIENCE 2017; 8:2013. [PMID: 29230233 PMCID: PMC5711826 DOI: 10.3389/fpls.2017.02013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 11/13/2017] [Indexed: 05/22/2023]
Abstract
Fusarium fujikuroi causing bakanae disease has emerged as one of the major pathogen of rice across the world. The study aims to comparative genomic analysis of Fusarium fujikuroi isolates and identification of the secretary proteins of the fungus involved in rice pathogenesis. In the present study, F. fujikuroi isolate "F250" was sequenced with an assembly size of 42.47 Mb providing coverage of 96.89% on reference IMI58289 genome. A total of 13,603 protein-coding genes were predicted from genome assembly. The average gene density in the F. fujikuroi genome was 315.10 genes per Mb with an average gene length of 1.67 kb. Additionally, 134,374 single nucleotide polymorphisms (SNPs) are identified against IMI58289 isolate, with an average SNP density of 3.11 per kb of genome. Repetitive elements represent approximately 270,550 bp, which is 0.63% of the total genome. In total, 3,109 simple sequence repeats (SSRs), including 302 compound SSRs are identified in the 8,656 scaffolds. Comparative analysis of the isolates of F. fujikuroi revealed that they shared a total of 12,240 common clusters with F250 showing higher similarity with IMI58289. A total of 1,194 secretory proteins were identified in its genome among which there were 356 genes encoding carbohydrate active enzymes (CAZymes) capable for degradation of complex polysaccharides. Out of them glycoside hydrolase (GH) families were most prevalent (41%) followed by carbohydrate esterase (CE). Out of them CE8 (4 genes), PL1 (10 genes), PL3 (5 genes), and GH28 (8 genes) were prominent plant cell wall degrading enzymes families in F250 secretome. Besides this, 585 genes essential for the pathogen-host interactions were also identified. Selected genes were validated through quantitative real-time PCR analyses in resistant and susceptible genotypes of rice at different days of inoculation. The data offers a better understanding of F. fujikuroi genome and will help us enhance our knowledge on Fusarium fujikuroi-rice interactions.
Collapse
Affiliation(s)
- Bishnu M. Bashyal
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
- *Correspondence: Bishnu M. Bashyal,
| | - Kirti Rawat
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Sapna Sharma
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Deepika Kulshreshtha
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - S. Gopala Krishnan
- Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Ashok K. Singh
- Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Himanshu Dubey
- ICAR-National Research Centre on Plant Biotechnology, New Delhi, India
| | | | - T. R. Sharma
- ICAR-National Research Centre on Plant Biotechnology, New Delhi, India
| | - Rashmi Aggarwal
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| |
Collapse
|
7
|
Şestacova T, Giscă I, Cucereavîi A, Port A, Duca M. Expression of defence-related genes in sunflower infected with broomrape. BIOTECHNOL BIOTEC EQ 2016. [DOI: 10.1080/13102818.2016.1179591] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Tatiana Şestacova
- Laboratory of Genomics, University Center of Molecular Biology, University of the Academy of Sciences of Moldova, Chisinau, Republic of Moldova
| | - Ion Giscă
- Research Department, AMG-Agroselect Comerţ Company, Soroca, Republic of Moldova
| | - Aliona Cucereavîi
- Research Department, AMG-Agroselect Comerţ Company, Soroca, Republic of Moldova
| | - Angela Port
- Laboratory of Genomics, University Center of Molecular Biology, University of the Academy of Sciences of Moldova, Chisinau, Republic of Moldova
| | - Maria Duca
- Laboratory of Genomics, University Center of Molecular Biology, University of the Academy of Sciences of Moldova, Chisinau, Republic of Moldova
| |
Collapse
|
8
|
Foley RC, Kidd BN, Hane JK, Anderson JP, Singh KB. Reactive Oxygen Species Play a Role in the Infection of the Necrotrophic Fungi, Rhizoctonia solani in Wheat. PLoS One 2016; 11:e0152548. [PMID: 27031952 PMCID: PMC4816451 DOI: 10.1371/journal.pone.0152548] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 03/16/2016] [Indexed: 01/18/2023] Open
Abstract
Rhizoctonia solani is a nectrotrophic fungal pathogen that causes billions of dollars of damage to agriculture worldwide and infects a broad host range including wheat, rice, potato and legumes. In this study we identify wheat genes that are differentially expressed in response to the R. solani isolate, AG8, using microarray technology. A significant number of wheat genes identified in this screen were involved in reactive oxygen species (ROS) production and redox regulation. Levels of ROS species were increased in wheat root tissue following R. solani infection as determined by Nitro Blue Tetrazolium (NBT), 3,3'-diaminobenzidine (DAB) and titanium sulphate measurements. Pathogen/ROS related genes from R. solani were also tested for expression patterns upon wheat infection. TmpL, a R. solani gene homologous to a gene associated with ROS regulation in Alternaria brassicicola, and OAH, a R. solani gene homologous to oxaloacetate acetylhydrolase which has been shown to produce oxalic acid in Sclerotinia sclerotiorum, were highly induced in R. solani when infecting wheat. We speculate that the interplay between the wheat and R. solani ROS generating proteins may be important for determining the outcome of the wheat/R. solani interaction.
Collapse
Affiliation(s)
- Rhonda C. Foley
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
| | - Brendan N. Kidd
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
| | - James K. Hane
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
| | - Jonathan P. Anderson
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
- The UWA Institute of Agriculture, University of Western Australia, Crawley, WA, Australia
| | - Karam B. Singh
- CSIRO Agriculture, Centre for Environment and Life Sciences, Floreat, WA, Australia
- The UWA Institute of Agriculture, University of Western Australia, Crawley, WA, Australia
- * E-mail:
| |
Collapse
|
9
|
Ghosh S, Gupta SK, Jha G. Identification and functional analysis of AG1-IA specific genes of Rhizoctonia solani. Curr Genet 2014; 60:327-41. [PMID: 25070039 DOI: 10.1007/s00294-014-0438-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 07/10/2014] [Accepted: 07/10/2014] [Indexed: 11/24/2022]
Abstract
Rhizoctonia solani is an important necrotrophic fungal pathogen which causes disease on diverse plant species. It has been classified into 14 genetically distinct anastomosis groups (AGs), however, very little is known about their genomic diversity. AG1-IA causes sheath blight disease in rice and controlling this disease remains a challenge for sustainable rice cultivation. Recently the draft genome sequences of AG1-IA (rice isolate) and AG1-IB (lettuce isolate) had become publicly available. In this study, using comparative genomics, we report identification of 3,942 R. solani genes that are uniquely present in AG1-IA. Many of these genes encode important biological, molecular functions and exhibit dynamic expression during in-planta growth of the pathogen in rice. Based upon sequence similarity with genes that are required for plant and human/zoonotic diseases, we identified several putative virulence/pathogenicity determinants amongst AG1-IA specific genes. While studying the expression of 19 randomly selected genes, we identified three genes highly up-regulated during in-planta growth. The detailed in silico characterization of these genes and extent of their up-regulation in different rice genotypes, having variable degree of disease susceptibility, suggests their importance in rice-Rhizoctonia interactions. In summary, the present study reports identification, functional characterization of AG1-IA specific genes and predicts important virulence determinants that might enable the pathogen to grow inside hostile plant environment. Further characterization of these genes would shed useful insights about the pathogenicity mechanism of AG1-IA on rice.
Collapse
Affiliation(s)
- Srayan Ghosh
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | | | | |
Collapse
|
10
|
Okubara PA, Dickman MB, Blechl AE. Molecular and genetic aspects of controlling the soilborne necrotrophic pathogens Rhizoctonia and Pythium. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 228:61-70. [PMID: 25438786 DOI: 10.1016/j.plantsci.2014.02.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 01/22/2014] [Accepted: 02/03/2014] [Indexed: 05/20/2023]
Abstract
The soilborne necrotrophic pathogens Rhizoctonia and Pythium infect a wide range of crops in the US and worldwide. These pathogens pose challenges to growers because the diseases they cause are not adequately controlled by fungicides, rotation or, for many hosts, natural genetic resistance. Although a combination of management practices are likely to be required for control of Rhizoctonia and Pythium, genetic resistance remains a key missing component. This review discusses the recent deployment of introduced genes and genome-based information for control of Rhizoctonia, with emphasis on three pathosystems: Rhizoctonia solani AG8 and wheat, R. solani AG1-IA and rice, and R. solani AG3 or AG4 and potato. Molecular mechanisms underlying disease suppression will be addressed, if appropriate. Although less is known about genes and factors suppressive to Pythium, pathogen genomics and biological control studies are providing useful leads to effectors and antifungal factors. Prospects for resistance to Rhizoctonia and Pythium spp. will continue to improve with growing knowledge of pathogenicity strategies, host defense gene action relative to the pathogen infection process, and the role of environmental factors on pathogen-host interactions.
Collapse
Affiliation(s)
- Patricia A Okubara
- USDA-ARS, Root Disease and Biological Control Research Unit, Pullman, WA, 99164-6430, USA.
| | - Martin B Dickman
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2123, USA
| | - Ann E Blechl
- USDA-ARS, Crop Improvement and Utilization Research Unit, 800 Buchanan Street, Albany, CA, 94710-1105, USA
| |
Collapse
|
11
|
Rioux RA, Shultz J, Garcia M, Willis DK, Casler M, Bonos S, Smith D, Kerns J. Sclerotinia homoeocarpa overwinters in turfgrass and is present in commercial seed. PLoS One 2014; 9:e110897. [PMID: 25333928 PMCID: PMC4204931 DOI: 10.1371/journal.pone.0110897] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 09/25/2014] [Indexed: 11/18/2022] Open
Abstract
Dollar spot is the most economically important disease of amenity turfgrasses in the United States, yet little is known about the source of primary inoculum for this disease. With the exception of a few isolates from the United Kingdom, Sclerotinia homoeocarpa, the causal agent of dollar spot, does not produce spores. Consequently, it was assumed that overwintering of this organism in soil, thatch, and plant debris provides primary inoculum for dollar spot epidemics. Overwintering of S. homoeocarpa in roots and shoots of symptomatic and asymptomatic creeping bentgrass turfgrass was quantified over the course of a three-year field experiment. Roots did not consistently harbor S. homoeocarpa, whereas S. homoeocarpa was isolated from 30% of symptomatic shoots and 10% of asymptomatic shoots in the spring of two out of three years. The presence of stroma-like pathogen material on leaf blades was associated with an increase in S. homoeocarpa isolation and colony diameter at 48 hpi. Commercial seed has also been hypothesized to be a potential source of initial inoculum for S. homoeocarpa. Two or more commercial seed lots of six creeping bentgrass cultivars were tested for contamination with S. homoeocarpa using culture-based and molecular detection methods. A viable, pathogenic isolate of S. homoeocarpa was isolated from one commercial seed lot and contamination of this lot was confirmed with nested PCR using S. homoeocarpa specific primers. A sensitive nested PCR assay detected S. homoeocarpa contamination in eight of twelve (75%) commercial seed lots. Seed source, but not cultivar or resistance to dollar spot, influenced contamination by S. homoeocarpa. Overall, this research suggests that seeds are a potential source of initial inoculum for dollar spot epidemics and presents the need for further research in this area.
Collapse
Affiliation(s)
- Renée A. Rioux
- Department of Plant of Plant Path Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- NewLeaf Symbiotics, BRDG Park, St. Louis, Missouri, United States of America
| | - Jeanette Shultz
- Department of Plant of Plant Path Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Neuroscience, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Michelle Garcia
- Department of Plant of Plant Path Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Biological Sciences, University of Texas El-Paso, El Paso, Texas, United States of America
| | - David Kyle Willis
- Department of Plant of Plant Path Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Michael Casler
- USDA-ARS, U.S. Dairy Forage Research Center, Madison, Wisconsin, United States of America
| | - Stacy Bonos
- Department of Plant Science, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Damon Smith
- Department of Plant of Plant Path Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - James Kerns
- Department of Plant of Plant Path Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
| |
Collapse
|
12
|
Hane JK, Anderson JP, Williams AH, Sperschneider J, Singh KB. Genome sequencing and comparative genomics of the broad host-range pathogen Rhizoctonia solani AG8. PLoS Genet 2014; 10:e1004281. [PMID: 24810276 PMCID: PMC4014442 DOI: 10.1371/journal.pgen.1004281] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 02/20/2014] [Indexed: 11/30/2022] Open
Abstract
Rhizoctonia solani is a soil-borne basidiomycete fungus with a necrotrophic lifestyle which is classified into fourteen reproductively incompatible anastomosis groups (AGs). One of these, AG8, is a devastating pathogen causing bare patch of cereals, brassicas and legumes. R. solani is a multinucleate heterokaryon containing significant heterozygosity within a single cell. This complexity posed significant challenges for the assembly of its genome. We present a high quality genome assembly of R. solani AG8 and a manually curated set of 13,964 genes supported by RNA-seq. The AG8 genome assembly used novel methods to produce a haploid representation of its heterokaryotic state. The whole-genomes of AG8, the rice pathogen AG1-IA and the potato pathogen AG3 were observed to be syntenic and co-linear. Genes and functions putatively relevant to pathogenicity were highlighted by comparing AG8 to known pathogenicity genes, orthology databases spanning 197 phytopathogenic taxa and AG1-IA. We also observed SNP-level "hypermutation" of CpG dinucleotides to TpG between AG8 nuclei, with similarities to repeat-induced point mutation (RIP). Interestingly, gene-coding regions were widely affected along with repetitive DNA, which has not been previously observed for RIP in mononuclear fungi of the Pezizomycotina. The rate of heterozygous SNP mutations within this single isolate of AG8 was observed to be higher than SNP mutation rates observed across populations of most fungal species compared. Comparative analyses were combined to predict biological processes relevant to AG8 and 308 proteins with effector-like characteristics, forming a valuable resource for further study of this pathosystem. Predicted effector-like proteins had elevated levels of non-synonymous point mutations relative to synonymous mutations (dN/dS), suggesting that they may be under diversifying selection pressures. In addition, the distant relationship to sequenced necrotrophs of the Ascomycota suggests the R. solani genome sequence may prove to be a useful resource in future comparative analysis of plant pathogens.
Collapse
Affiliation(s)
- James K. Hane
- Molecular Plant Pathology and Crop Genomics Laboratory, Centre for Environment and Life Sciences, Division of Plant Industry, Commonwealth Scientific and Industrial Research Organisation, Floreat, Western Australia, Australia
| | - Jonathan P. Anderson
- Molecular Plant Pathology and Crop Genomics Laboratory, Centre for Environment and Life Sciences, Division of Plant Industry, Commonwealth Scientific and Industrial Research Organisation, Floreat, Western Australia, Australia
- The University of Western Australia Institute of Agriculture, University of Western Australia, Crawley, Western Australia, Australia
| | - Angela H. Williams
- Molecular Plant Pathology and Crop Genomics Laboratory, Centre for Environment and Life Sciences, Division of Plant Industry, Commonwealth Scientific and Industrial Research Organisation, Floreat, Western Australia, Australia
| | - Jana Sperschneider
- Molecular Plant Pathology and Crop Genomics Laboratory, Centre for Environment and Life Sciences, Division of Plant Industry, Commonwealth Scientific and Industrial Research Organisation, Floreat, Western Australia, Australia
| | - Karam B. Singh
- Molecular Plant Pathology and Crop Genomics Laboratory, Centre for Environment and Life Sciences, Division of Plant Industry, Commonwealth Scientific and Industrial Research Organisation, Floreat, Western Australia, Australia
- The University of Western Australia Institute of Agriculture, University of Western Australia, Crawley, Western Australia, Australia
| |
Collapse
|
13
|
Collins C, Keane TM, Turner DJ, O'Keeffe G, Fitzpatrick DA, Doyle S. Genomic and proteomic dissection of the ubiquitous plant pathogen, Armillaria mellea: toward a new infection model system. J Proteome Res 2013; 12:2552-70. [PMID: 23656496 PMCID: PMC3679558 DOI: 10.1021/pr301131t] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
![]()
Armillaria mellea is a major plant
pathogen. Yet, no large-scale “-omics” data are available
to enable new studies, and limited experimental models are available
to investigate basidiomycete pathogenicity. Here we reveal that the A. mellea genome comprises 58.35 Mb, contains 14473 gene
models, of average length 1575 bp (4.72 introns/gene). Tandem mass
spectrometry identified 921 mycelial (n = 629 unique)
and secreted (n = 183 unique) proteins. Almost 100
mycelial proteins were either species-specific or previously unidentified
at the protein level. A number of proteins (n = 111)
was detected in both mycelia and culture supernatant extracts. Signal
sequence occurrence was 4-fold greater for secreted (50.2%) compared
to mycelial (12%) proteins. Analyses revealed a rich reservoir of
carbohydrate degrading enzymes, laccases, and lignin peroxidases in
the A. mellea proteome, reminiscent of both basidiomycete
and ascomycete glycodegradative arsenals. We discovered that A. mellea exhibits a specific killing effect against Candida albicans during coculture. Proteomic investigation
of this interaction revealed the unique expression of defensive and
potentially offensive A. mellea proteins (n = 30). Overall, our data reveal new insights into the
origin of basidiomycete virulence and we present a new model system
for further studies aimed at deciphering fungal pathogenic mechanisms.
Collapse
Affiliation(s)
- Cassandra Collins
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co Kildare, Ireland
| | | | | | | | | | | |
Collapse
|