1
|
Zhou L, Mubeen M, Iftikhar Y, Zheng H, Zhang Z, Wen J, Khan RAA, Sajid A, Solanki MK, Sohail MA, Kumar A, Massoud EES, Chen L. Rice false smut pathogen: implications for mycotoxin contamination, current status, and future perspectives. Front Microbiol 2024; 15:1344831. [PMID: 38585697 PMCID: PMC10996400 DOI: 10.3389/fmicb.2024.1344831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 03/06/2024] [Indexed: 04/09/2024] Open
Abstract
Rice serves as a staple food across various continents worldwide. The rice plant faces significant threats from a range of fungal, bacterial, and viral pathogens. Among these, rice false smut disease (RFS) caused by Villosiclava virens is one of the devastating diseases in rice fields. This disease is widespread in major rice-growing regions such as China, Pakistan, Bangladesh, India, and others, leading to significant losses in rice plantations. Various toxins are produced during the infection of this disease in rice plants, impacting the fertilization process as well. This review paper lightens the disease cycle, plant immunity, and infection process during RFS. Mycotoxin production in RFS affects rice plants in multiple ways, although the exact phenomena are still unknown.
Collapse
Affiliation(s)
- Lei Zhou
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Mustansar Mubeen
- Department of Plant Pathology, College of Agriculture, University of Sargodha, Sargodha, Pakistan
| | - Yasir Iftikhar
- Department of Plant Pathology, College of Agriculture, University of Sargodha, Sargodha, Pakistan
| | - Hongxia Zheng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Zhenhao Zhang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Junli Wen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | | | - Ashara Sajid
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Manoj Kumar Solanki
- Department of Life Sciences and Biological Sciences, IES University, Bhopal, Madhya Pradesh, India
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice, Poland
| | - Muhammad Aamir Sohail
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Ajay Kumar
- Amity University of Biotechnology, Amity University, Noida, India
| | - Ehab El Sayed Massoud
- Biology Department, Faculty of Science and Arts in Dahran Aljnoub, King Khalid University, Abha, Saudi Arabia
| | - Liezhong Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| |
Collapse
|
2
|
Fill JM, Meadows I, Walker JL, Crandall RM, Kerrigan JL. Smut fungus (Langdonia walkerae) incidence is lower in two bunchgrass species (Aristida stricta and A. beyrichiana) after fires early in the year. Am J Bot 2024; 111:e16286. [PMID: 38366863 DOI: 10.1002/ajb2.16286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 12/04/2023] [Accepted: 12/04/2023] [Indexed: 02/18/2024]
Abstract
PREMISE In frequently burned southeastern USA pine-grassland communities, wiregrass (Aristida stricta and A. beyrichiana) are dominant bunchgrasses whose flowers are infected during flowering by a smut fungus (Langdonia walkerae). We hypothesized that because prescribed fire timing affects wiregrass flowering patterns, it could affect smut incidence (occurrence of smut on plants) and severity of infection in inflorescences and spikelets. Because soil order could influence plant susceptibility, we hypothesized that these patterns would differ between soil orders. We hypothesized differences between species as representative of geographic variation in this ecosystem. METHODS We surveyed the incidence and severity of L. walkerae in wiregrass populations (85 populations at 14 sites) that had been prescription burned at different times during the previous year. We used binomial regressions to test whether incidence and severity differed by burn day, soil order, or species, with site as a random effect. RESULTS Fires that occurred in the winter were associated with significantly lower incidence than fires later in the year (as the months progressed into summer). Plants growing on Spodosol soils were significantly less likely to be infected than those on other soils. More variation in incidence, however, was explained by site, suggesting that site-specific characteristics were important. Smut severity in inflorescences and spikelets was greater overall in populations of A. stricta than in southern populations (A. beyrichiana). CONCLUSIONS Our findings indicate that fire timing and soil order affect L. walkerae incidence in wiregrass plants, but neither appears to be associated with greater severity. Patterns of smut infection are related to site history and geographic variation.
Collapse
Affiliation(s)
- Jennifer M Fill
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, FL, 32611
| | - Inga Meadows
- Department of Entomology and Plant Pathology, Mountain Research Station, North Carolina State University, Waynesville, NC, 28786
| | - Joan L Walker
- US Forest Service Southern Research Station, Clemson, SC, 29631
| | - Raelene M Crandall
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, FL, 32611
| | - Julia L Kerrigan
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29634
| |
Collapse
|
3
|
Díaz MS, Figueroa AC, Alasino VR, Turco M, Fernández A, Marino B, Soria NW, Beltramo DM. Changes of lipids composition in different ontogenetic stages of Thecaphora frezii: expression of key enzymes for lipid biosynthetic pathways. J Appl Microbiol 2023; 134:6902077. [PMID: 36724262 DOI: 10.1093/jambio/lxac022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 07/15/2022] [Accepted: 10/14/2022] [Indexed: 02/03/2023]
Abstract
AIMS It is known that Thecaphora frezii produces peanut smut that generates numerous economic losses. For this reason, it is a priority to search for control strategies. In this sense, we investigated the lipid profile of this pathogen, as possible antifungal targets, regarding polar lipid composition, fatty acid profile, and transcriptional regulation of genes involved in each stage of the development. METHOD AND RESULTS Lipids from T. frezii teliospores, basidiospores, and hyphae were analyzed by HPLC/CAD and CG/FID. We found differences in the unsaturation levels as well as in the long-chain fatty acids along the stages. Phosphatidylcholine was the main component in the three development stages, followed by cardiolipins. Phosphatidylinositol, phosphatidylethanolamine, and lyso-phosphatidylethanolamine were found in similar amounts in all stages. Although ergosterol was not detected, we found two unsaponifiable lipids. In addition, we found transcripts that encode 28 enzymes involved in the biosynthesis of three lipids by RNA-Seq. CONCLUSIONS Thecaphora frezii shows changes in the composition of membrane lipids in different ontogenetic stages as well as in the expression of transcripts for enzymes involved in lipid biosynthesis.
Collapse
Affiliation(s)
- María S Díaz
- Centro de Excelencia en Productos y Procesos de Córdoba-OCOR-Hospital Colonia Santa María, Punilla, X5164 Santa María de Punilla, Cordoba, Argentina
| | - Ana C Figueroa
- Centro de Excelencia en Productos y Procesos de Córdoba-OCOR-Hospital Colonia Santa María, Punilla, X5164 Santa María de Punilla, Cordoba, Argentina
| | - Valeria R Alasino
- Centro de Excelencia en Productos y Procesos de Córdoba-OCOR-Hospital Colonia Santa María, Punilla, X5164 Santa María de Punilla, Cordoba, Argentina.,CONICET, Buenos Aires 1418, X5000IND Córdoba, Argentina
| | - Mauricio Turco
- Centro de Excelencia en Productos y Procesos de Córdoba-OCOR-Hospital Colonia Santa María, Punilla, X5164 Santa María de Punilla, Cordoba, Argentina
| | - Andrea Fernández
- Centro de Excelencia en Productos y Procesos de Córdoba-OCOR-Hospital Colonia Santa María, Punilla, X5164 Santa María de Punilla, Cordoba, Argentina
| | - Bibiana Marino
- Centro de Excelencia en Productos y Procesos de Córdoba-OCOR-Hospital Colonia Santa María, Punilla, X5164 Santa María de Punilla, Cordoba, Argentina
| | - Néstor W Soria
- Cátedra de Biotecnología, Facultad de Ciencias Químicas, Unidad Asociada al CONICET: Área de Cs. Agrarias, Ingeniería, Cs. Biológicas, Universidad Católica de Córdoba, X5016DHK Córdoba, Argentina
| | - Dante M Beltramo
- Centro de Excelencia en Productos y Procesos de Córdoba-OCOR-Hospital Colonia Santa María, Punilla, X5164 Santa María de Punilla, Cordoba, Argentina.,CONICET, Buenos Aires 1418, X5000IND Córdoba, Argentina.,Cátedra de Biotecnología, Facultad de Ciencias Químicas, Unidad Asociada al CONICET: Área de Cs. Agrarias, Ingeniería, Cs. Biológicas, Universidad Católica de Córdoba, X5016DHK Córdoba, Argentina
| |
Collapse
|
4
|
Song X, Mo F, Yan M, Zhang X, Zhang B, Huang X, Huang D, Pan Y, Verma KK, Li YR. Effect of Smut Infection on the Photosynthetic Physiological Characteristics and Related Defense Enzymes of Sugarcane. Life (Basel) 2022; 12:life12081201. [PMID: 36013380 PMCID: PMC9410379 DOI: 10.3390/life12081201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 11/23/2022]
Abstract
Pathogen infection seriously affects plant development and crop productivity, sometimes causing total crop failure. In this study, artificial stab inoculation was used to inoculate sugarcane smut. The changes in leaf gas exchange, chlorophyll fluorescence variables, and related defense enzyme activities were measured in sugarcane cultivar ROC22 after pathogen infection. The results showed that the net photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr) downregulated in the first three days after smut infection and upregulated on the fourth day; intercellular CO2 concentration (Ci) increased in the first three days of smut infection and reduced on the fourth day. The chlorophyll fluorescence parameters, i.e., Fo, Fm, Fv/Fm, Fs, and Fv′/Fm′ decreased at the initial stage of pathogen infection but increased rapidly up to 3 days after smut infection. It can be seen that sugarcane seedlings showed a positive response to pathogen infection. The correlation coefficient relationship between Pn, gs, and Tr reached above 0.800, showing a significant correlation; Ci was positively correlated with Fv′/Fm′ and ΦPSII, reaching above 0.800 and showing a significant correlation; Fo positively correlated with Fv/Fm, Fs, and ETR; Fv /Fm was positively correlated with Fv′/Fm′; Fs significantly correlated with Fv′/Fm′; and Fv′/Fm′ positively correlated with ΦPSII. After inoculation with smut, the related defense enzymes, i.e., POD, SOD, PPO, and PAL, were increased and upregulated; photosynthetic parameters can be associated with an increase in enzymatic activities. The results of this study will help to further study of the response mechanism to smut in the sugarcane growing period and provide a theoretical reference for sugarcane resistance to smut breeding.
Collapse
Affiliation(s)
- Xiupeng Song
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China
| | - Fenglian Mo
- College of Agriculture, Guangxi University, Nanning 530004, China
| | - Meixin Yan
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China
| | - Xiaoqiu Zhang
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China
| | - Baoqing Zhang
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China
| | - Xing Huang
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China
| | - Dongmei Huang
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China
| | - Yangfei Pan
- College of Agriculture, Guangxi University, Nanning 530004, China
| | - Krishan K. Verma
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China
- Correspondence: (K.K.V.); (Y.-R.L.)
| | - Yang-Rui Li
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs/Guangxi Key Laboratory of Sugarcane Genetic Improvement, Nanning 530007, China
- College of Agriculture, Guangxi University, Nanning 530004, China
- Correspondence: (K.K.V.); (Y.-R.L.)
| |
Collapse
|
5
|
Wang Z, Solanki MK, Yu ZX, Anas M, Dong DF, Xing YX, Malviya MK, Pang F, Li YR. Genome Characteristics Reveal the Biocontrol Potential of Actinobacteria Isolated From Sugarcane Rhizosphere. Front Microbiol 2022; 12:797889. [PMID: 35003029 PMCID: PMC8740303 DOI: 10.3389/fmicb.2021.797889] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
To understand the beneficial interaction of sugarcane rhizosphere actinobacteria in promoting plant growth and managing plant diseases, this study investigated the potential role of sugarcane rhizospheric actinobacteria in promoting plant growth and antagonizing plant pathogens. We isolated 58 actinobacteria from the sugarcane rhizosphere, conducted plant growth-promoting (PGP) characteristics research, and tested the pathogenic fungi in vitro. Results showed that BTU6 (Streptomyces griseorubiginosus), the most representative strain, regulates plant defense enzyme activity and significantly enhances sugarcane smut resistance by regulating stress resistance-related enzyme (substances (POD, PAL, PPO, TP) in sugarcane) activity in sugarcane. The genomic evaluation indicated that BTU6 has the ability to biosynthesize chitinase, β-1,3-glucanase, and various secondary metabolites and plays an essential role in the growth of sugarcane plants under biotic stress. Potential mechanisms of the strain in improving the disease resistance of sugarcane plants and its potential in biodegrading exogenous chemicals were also revealed. This study showed the importance of sugarcane rhizosphere actinobacteria in microbial ecology and plant growth promotion.
Collapse
Affiliation(s)
- Zhen Wang
- Guangxi Key Laboratory of Agricultural Resources Chemistry and Biotechnology, College of Biology and Pharmacy, Yulin Normal University, Yulin, China.,Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Guangxi Key Laboratory of Sugarcane Genetic Improvement, Ministry of Agriculture, Sugarcane Research Institute of Guangxi Academy of Agricultural Sciences, Nanning, China.,Agricultural College, Guangxi University, Nanning, China
| | - Manoj Kumar Solanki
- Plant Cytogenetics and Molecular Biology Group, Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Katowice, Poland
| | - Zhuo-Xin Yu
- Agricultural College, Guangxi University, Nanning, China
| | - Muhammad Anas
- Agricultural College, Guangxi University, Nanning, China
| | - Deng-Feng Dong
- Agricultural College, Guangxi University, Nanning, China
| | - Yong-Xiu Xing
- Agricultural College, Guangxi University, Nanning, China
| | - Mukesh Kumar Malviya
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Guangxi Key Laboratory of Sugarcane Genetic Improvement, Ministry of Agriculture, Sugarcane Research Institute of Guangxi Academy of Agricultural Sciences, Nanning, China
| | - Fei Pang
- Guangxi Key Laboratory of Agricultural Resources Chemistry and Biotechnology, College of Biology and Pharmacy, Yulin Normal University, Yulin, China
| | - Yang-Rui Li
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Guangxi Key Laboratory of Sugarcane Genetic Improvement, Ministry of Agriculture, Sugarcane Research Institute of Guangxi Academy of Agricultural Sciences, Nanning, China.,Agricultural College, Guangxi University, Nanning, China
| |
Collapse
|
6
|
Gao Y, Zhou S, Huang Y, Zhang B, Xu Y, Zhang G, Lakshmanan P, Yang R, Zhou H, Huang D, Liu J, Tan H, He W, Yang C, Duan W. Quantitative Trait Loci Mapping and Development of KASP Marker Smut Screening Assay Using High-Density Genetic Map and Bulked Segregant RNA Sequencing in Sugarcane ( Saccharum spp.). Front Plant Sci 2022; 12:796189. [PMID: 35069651 PMCID: PMC8766830 DOI: 10.3389/fpls.2021.796189] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 12/13/2021] [Indexed: 06/02/2023]
Abstract
Sugarcane is one of the most important industrial crops globally. It is the second largest source of bioethanol, and a major crop for biomass-derived electricity and sugar worldwide. Smut, caused by Sporisorium scitamineum, is a major sugarcane disease in many countries, and is managed by smut-resistant varieties. In China, smut remains the single largest constraint for sugarcane production, and consequently it impacts the value of sugarcane as an energy feedstock. Quantitative trait loci (QTLs) associated with smut resistance and linked diagnostic markers are valuable tools for smut resistance breeding. Here, we developed an F1 population (192 progeny) by crossing two sugarcane varieties with contrasting smut resistance and used for genome-wide single nucleotide polymorphism (SNP) discovery and mapping, using a high-throughput genotyping method called "specific locus amplified fragment sequencing (SLAF-seq) and bulked-segregant RNA sequencing (BSR-seq). SLAF-seq generated 148,500 polymorphic SNP markers. Using SNP and previously identified SSR markers, an integrated genetic map with an average 1.96 cM marker interval was produced. With this genetic map and smut resistance scores of the F1 individuals from four crop years, 21 major QTLs were mapped, with a phenotypic variance explanation (PVE) > 8.0%. Among them, 10 QTLs were stable (repeatable) with PVEs ranging from 8.0 to 81.7%. Further, four QTLs were detected based on BSR-seq analysis. aligning major QTLs with the genome of a sugarcane progenitor Saccharum spontaneum, six markers were found co-localized. Markers located in QTLs and functional annotation of BSR-seq-derived unigenes helped identify four disease resistance candidate genes located in major QTLs. 77 SNPs from major QTLs were then converted to Kompetitive Allele-Specific PCR (KASP) markers, of which five were highly significantly linked to smut resistance. The co-localized QTLs, candidate resistance genes, and KASP markers identified in this study provide practically useful tools for marker-assisted sugarcane smut resistance breeding.
Collapse
Affiliation(s)
- Yijing Gao
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Shan Zhou
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Yuxin Huang
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Baoqing Zhang
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Yuhui Xu
- Adsen Biotechnology Co., Ltd., Urumchi, China
| | - Gemin Zhang
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Prakash Lakshmanan
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
- Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Chongqing, China
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St Lucia, QLD, Australia
| | - Rongzhong Yang
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Hui Zhou
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Dongliang Huang
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Junxian Liu
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Hongwei Tan
- Guangxi Academy of Agricultural Sciences, Nanning, China
| | - Weizhong He
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Cuifang Yang
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| | - Weixing Duan
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs, Sugarcane Research Center, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Chinese Academy of Agricultural Sciences, Nanning, China
| |
Collapse
|
7
|
Jin F, Liu J, Wu E, Yang P, Gao J, Gao X, Feng B. Leaf Transcriptome Analysis of Broomcorn Millet Uncovers Key Genes and Pathways in Response to Sporisorium destruens. Int J Mol Sci 2021; 22:9542. [PMID: 34502461 DOI: 10.3390/ijms22179542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/19/2021] [Accepted: 08/27/2021] [Indexed: 01/26/2023] Open
Abstract
Broomcorn millet (Panicum miliaceum L.) affected by smut (caused by the pathogen Sporisorium destruens) has reduced production yields and quality. Determining the tolerance of broomcorn millet varieties is essential for smut control. This study focuses on the differences in the phenotypes, physiological characteristics, and transcriptomes of resistant and susceptible broomcorn millet varieties under Sporisorium destruens stress. In diseased broomcorn millet, the plant height and stem diameter were reduced, while the number of nodes increased. After infection, the activities of superoxide dismutase and peroxidase decreased, and malondialdehyde and relative chlorophyll content (SPAD) decreased. Transcriptome analysis showed 514 and 5452 differentially expressed genes (DEGs) in the resistant and susceptible varieties, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of DEGs showed that pathways related to plant disease resistance, such as phenylpropanoid biosynthesis, plant–pathogen interaction, and plant hormone signal transduction, were significantly enriched. In addition, the transcriptome changes of cluster leaves and normal leaves in diseased broomcorn millet were analysed. Gene ontology and KEGG enrichment analyses indicated that photosynthesis played an important role in both varieties. These findings lay a foundation for future research on the molecular mechanism of the interaction between broomcorn millet and Sporisorium destruens.
Collapse
|
8
|
Vicente C, Legaz ME, Sánchez-Elordi E. Physiological Basis of Smut Infectivity in the Early Stages of Sugar Cane Colonization. J Fungi (Basel) 2021; 7:44. [PMID: 33445484 DOI: 10.3390/jof7010044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/04/2021] [Accepted: 01/09/2021] [Indexed: 12/11/2022] Open
Abstract
Sugar cane smut (Sporisorium scitamineum) interactions have been traditionally considered from the plant’s point of view: How can resistant sugar cane plants defend themselves against smut disease? Resistant plants induce several defensive mechanisms that oppose fungal attacks. Herein, an overall view of Sporisorium scitamineum’s mechanisms of infection and the defense mechanisms of plants are presented. Quorum sensing effects and a continuous reorganization of cytoskeletal components, where actin, myosin, and microtubules are required to work together, seem to be some of the keys to a successful attack.
Collapse
|
9
|
Plücker L, Bösch K, Geißl L, Hoffmann P, Göhre V. Genetic Manipulation of the Brassicaceae Smut Fungus Thecaphora thlaspeos. J Fungi (Basel) 2021; 7:jof7010038. [PMID: 33435409 PMCID: PMC7826943 DOI: 10.3390/jof7010038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/20/2022] Open
Abstract
Investigation of plant–microbe interactions greatly benefit from genetically tractable partners to address, molecularly, the virulence and defense mechanisms. The smut fungus Ustilago maydis is a model pathogen in that sense: efficient homologous recombination and a small genome allow targeted modification. On the host side, maize is limiting with regard to rapid genetic alterations. By contrast, the model plant Arabidopsis thaliana is an excellent model with a vast amount of information and techniques as well as genetic resources. Here, we present a transformation protocol for the Brassicaceae smut fungus Thecaphora thlaspeos. Using the well-established methodology of protoplast transformation, we generated the first reporter strains expressing fluorescent proteins to follow mating. As a proof-of-principle for homologous recombination, we deleted the pheromone receptor pra1. As expected, this mutant cannot mate. Further analysis will contribute to our understanding of the role of mating for infection biology in this novel model fungus. From now on, the genetic manipulation of T. thlaspeos, which is able to colonize the model plant A. thaliana, provides us with a pathosystem in which both partners are genetically amenable to study smut infection biology.
Collapse
Affiliation(s)
| | | | | | | | - Vera Göhre
- Correspondence: ; Tel.: +49-211-811-1529
| |
Collapse
|
10
|
Singh P, Song QQ, Singh RK, Li HB, Solanki MK, Malviya MK, Verma KK, Yang LT, Li YR. Proteomic Analysis of the Resistance Mechanisms in Sugarcane during Sporisorium scitamineum Infection. Int J Mol Sci 2019; 20:E569. [PMID: 30699953 DOI: 10.3390/ijms20030569] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/26/2019] [Accepted: 01/27/2019] [Indexed: 01/10/2023] Open
Abstract
Smut disease is caused by Sporisorium scitamineum, an important sugarcane fungal pathogen causing an extensive loss in yield and sugar quality. The available literature suggests that there are two types of smut resistance mechanisms: external resistance by physical or chemical barriers and intrinsic internal resistance mechanisms operating at host–pathogen interaction at cellular and molecular levels. The nature of smut resistance mechanisms, however, remains largely unknown. The present study investigated the changes in proteome occurring in two sugarcane varieties with contrasting susceptibility to smut—F134 and NCo310—at whip development stage after S. scitamineum infection. Total proteins from pathogen inoculated and uninoculated (control) leaves were separated by two-dimensional gel electrophoresis (2D-PAGE). Protein identification was performed using BLASTp and tBLASTn against NCBI nonredundant protein databases and EST databases, respectively. A total of thirty proteins spots representing differentially expressed proteins (DEPs), 16 from F134 and 14 from NCo310, were identified and analyzed by MALDI-TOF/TOF MS. In F134, 4 DEPs were upregulated and nine were downregulated, while, nine were upregulated and three were downregulated in NCo310. The DEPs were associated with DNA binding, metabolic processes, defense, stress response, photorespiration, protein refolding, chloroplast, nucleus and plasma membrane. Finally, the expression of CAT, SOD, and PAL with recognized roles in S. scitamineum infection in both sugarcane verities were analyzed by real-time quantitative PCR (RT-qPCR) technique. Identification of genes critical for smut resistance in sugarcane will increase our knowledge of S. scitamineum-sugarcane interaction and help to develop molecular and conventional breeding strategies for variety improvement.
Collapse
|
11
|
Abstract
The biotrophic maize head smut fungus Sporisorium reilianum is a close relative of the tumour-inducing maize smut fungus Ustilago maydis with a distinct disease aetiology. Maize infection with S. reilianum occurs at the seedling stage, but spores first form in inflorescences after a long endophytic growth phase. To identify S. reilianum-specific virulence effectors, we defined two gene sets by genome comparison with U. maydis and with the barley smut fungus Ustilago hordei. We tested virulence function by individual and cluster deletion analysis of 66 genes and by using a sensitive assay for virulence evaluation that considers both disease incidence (number of plants with a particular symptom) and disease severity (number and strength of symptoms displayed on any individual plant). Multiple deletion strains of S. reilianum lacking genes of either of the two sets (sr10057, sr10059, sr10079, sr10703, sr11815, sr14797 and clusters uni5-1, uni6-1, A1A2, A1, A2) were affected in virulence on the maize cultivar 'Gaspe Flint', but each of the individual gene deletions had only a modest impact on virulence. This indicates that the virulence of S. reilianum is determined by a complex repertoire of different effectors which each contribute incrementally to the aggressiveness of the pathogen.
Collapse
Affiliation(s)
- Hassan Ghareeb
- Department of Molecular Biology of Plant–Microbe InteractionsAlbrecht‐von‐Haller Institute of Plant Sciences, Schwann‐Schleiden Research Center for Molecular Cell Biology, Georg‐August‐Universität GöttingenJulia‐Lermontowa‐Weg 3Göttingen37077Germany
- Department of Organismic InteractionsMax Planck Institute for Terrestrial MicrobiologyKarl‐von‐Frisch Straße 10Marburg35043Germany
- Department of Plant BiotechnologyNational Research CentreCairo12311Egypt
- Present address:
Georg‐August‐Universität Göttingen, Plant Cell Biology, Albrecht‐von‐Haller Institute of Plant SciencesJulia‐Lermontowa‐Weg 3Göttingen37077Germany
| | - Yulei Zhao
- Department of Molecular Biology of Plant–Microbe InteractionsAlbrecht‐von‐Haller Institute of Plant Sciences, Schwann‐Schleiden Research Center for Molecular Cell Biology, Georg‐August‐Universität GöttingenJulia‐Lermontowa‐Weg 3Göttingen37077Germany
- Department of Microbial GeneticsInstitute of Applied Microbiology, Aachen Biology and Biotechnology, RWTH Aachen UniversityWorringer Weg 1Aachen52074Germany
| | - Jan Schirawski
- Department of Molecular Biology of Plant–Microbe InteractionsAlbrecht‐von‐Haller Institute of Plant Sciences, Schwann‐Schleiden Research Center for Molecular Cell Biology, Georg‐August‐Universität GöttingenJulia‐Lermontowa‐Weg 3Göttingen37077Germany
- Department of Organismic InteractionsMax Planck Institute for Terrestrial MicrobiologyKarl‐von‐Frisch Straße 10Marburg35043Germany
- Department of Microbial GeneticsInstitute of Applied Microbiology, Aachen Biology and Biotechnology, RWTH Aachen UniversityWorringer Weg 1Aachen52074Germany
| |
Collapse
|
12
|
Marques JPR, Hoy JW, Appezzato-da-Glória B, Viveros AFG, Vieira MLC, Baisakh N. Sugarcane Cell Wall-Associated Defense Responses to Infection by Sporisorium scitamineum. Front Plant Sci 2018; 9:698. [PMID: 29875793 PMCID: PMC5974332 DOI: 10.3389/fpls.2018.00698] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 05/07/2018] [Indexed: 05/08/2023]
Abstract
The plant cell wall is known to be the first barrier against plant pathogens. Detailed information about sugarcane cell wall-associated defense responses to infection by the causal agent of smut, Sporisorium scitamineum, is scarce. Herein, (immuno)histochemical analysis of two smut resistant and two susceptible sugarcane cultivars was conducted to understand host cell wall structural and compositional modifications in response to fungal infection. Results showed that the fungus grew on the surface and infected the outermost bud scale of both susceptible and resistant cultivars. The present findings also supported the existence of early (24 h after inoculation) and later (72-96 h after inoculation) inducible histopathological responses related to the cell wall modification in resistant cultivars. Lignin and phenolic compounds accumulated during early stages of infection. Later infection response was characterized by the formation of a protective barrier layer with lignin, cellulose and arabinoxylan in the cell walls. Overall, the results suggest possible induction of cell wall-modified responses in smut resistant cultivars to prevent initial entry of the fungus into the meristematic tissues.
Collapse
Affiliation(s)
- João P. R. Marques
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
- Genetics Department, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil
| | - Jeffrey W. Hoy
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Beatriz Appezzato-da-Glória
- Biological Science Department, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil
| | - Andrés F. G. Viveros
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Maria L. C. Vieira
- Genetics Department, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, Brazil
| | - Niranjan Baisakh
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| |
Collapse
|
13
|
Kretschmer M, Croll D, Kronstad JW. Maize susceptibility to Ustilago maydis is influenced by genetic and chemical perturbation of carbohydrate allocation. Mol Plant Pathol 2017; 18:1222-1237. [PMID: 27564861 PMCID: PMC6638311 DOI: 10.1111/mpp.12486] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/15/2016] [Accepted: 08/25/2016] [Indexed: 05/03/2023]
Abstract
The ability of biotrophic fungi to metabolically adapt to the host environment is a critical factor in fungal diseases of crop plants. In this study, we analysed the transcriptome of maize tumours induced by Ustilago maydis to identify key features underlying metabolic shifts during disease. Among other metabolic changes, this analysis highlighted modifications during infection in the transcriptional regulation of carbohydrate allocation and starch metabolism. We confirmed the relevance of these changes by establishing that symptom development was altered in an id1 (indeterminate1) mutant that showed increased accumulation of sucrose as well as being defective in the vegetative to reproductive transition. We further established the relevance of specific metabolic functions related to carbohydrate allocation by assaying disease in su1 (sugary1) mutant plants with altered starch metabolism and in plants treated with glucose, sucrose and silver nitrate during infection. We propose that specific regulatory and metabolic changes influence the balance between susceptibility and resistance by altering carbon allocation to promote fungal growth or to influence plant defence. Taken together, these studies reveal key aspects of metabolism that are critical for biotrophic adaptation during the maize-U. maydis interaction.
Collapse
Affiliation(s)
- Matthias Kretschmer
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
| | - Daniel Croll
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
- Present address:
Institute of Integrative BiologyETH Zürich8092 ZürichSwitzerland
| | - James W. Kronstad
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverBCV6T 1Z4Canada
| |
Collapse
|
14
|
Kretschmer M, Croll D, Kronstad JW. Chloroplast-associated metabolic functions influence the susceptibility of maize to Ustilago maydis. Mol Plant Pathol 2017; 18:1210-1221. [PMID: 27564650 PMCID: PMC6638283 DOI: 10.1111/mpp.12485] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/15/2016] [Accepted: 08/25/2016] [Indexed: 05/10/2023]
Abstract
Biotrophic fungal pathogens must evade or suppress plant defence responses to establish a compatible interaction in living host tissue. In addition, metabolic changes during disease reflect both the impact of nutrient acquisition by the fungus to support proliferation and the integration of metabolism with the plant defence response. In this study, we used transcriptome analyses to predict that the chloroplast and associated functions are important for symptom formation by the biotrophic fungus Ustilago maydis on maize. We tested our prediction by examining the impact on disease of a genetic defect (whirly1) in chloroplast function. In addition, we examined whether disease was influenced by inhibition of glutamine synthetase by glufosinate (impacting amino acid biosynthesis) or inhibition of 3-phosphoshikimate 1-carboxyvinyltransferase by glyphosate (influencing secondary metabolism). All of these perturbations increased the severity of disease, thus suggesting a contribution to resistance. Overall, these findings provide a framework for understanding the components of host metabolism that benefit the plant versus the pathogen during a biotrophic interaction. They also reinforce the emerging importance of the chloroplast as a mediator of plant defence.
Collapse
Affiliation(s)
- Matthias Kretschmer
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
| | - Daniel Croll
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
- Present address:
Institute of Integrative BiologyETH Zürich8092 ZürichSwitzerland
| | - James W. Kronstad
- Michael Smith Laboratories, University of British ColumbiaVancouverBCV6T 1Z4Canada
- Department of Microbiology and ImmunologyUniversity of British ColumbiaVancouverBCV6T 1Z4Canada
| |
Collapse
|
15
|
Su Y, Wang Z, Xu L, Peng Q, Liu F, Li Z, Que Y. Early Selection for Smut Resistance in Sugarcane Using Pathogen Proliferation and Changes in Physiological and Biochemical Indices. Front Plant Sci 2016; 7:1133. [PMID: 27516769 PMCID: PMC4963460 DOI: 10.3389/fpls.2016.01133] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/15/2016] [Indexed: 05/08/2023]
Abstract
Sugarcane smut disease, caused by Sporisorium scitamineum, significantly decreases yield and use of resistant cultivars is the most cost-effective measure for disease control. Current field testing methods for identification of smut resistance are time-consuming and hindered by environmental variability. Our goal was to develop an efficient and reliable resistance identification technique that is rapid, performed in a controlled environment, and stable. Nine sugarcane cultivars with different phenotypic resistance levels were selected. TaqMan quantitative real-time polymerase chain reaction analysis was performed to measure copy number changes of smut pathogen in sugarcane buds at 0-7 days after needle puncture inoculation. There was a positive correlation between time after inoculation and the amount of smut pathogen in the sugarcane bud. This reached a peak value on 7 days, and the copy number of S. scitamineum increased in the following order: YZ03-258, FN40, YZ01-1413, GT02-467, ROC22, YT96-86, YZ03-103, FN39, LC05-136. After smut pathogen inoculation, differences in the physiological and biochemical indices of the nine cultivars were observed. Peroxidase, ascorbate peroxidase, catalase, superoxide dismutase, β-1,3-glucanase, and malondialdehyde were grouped into three main components, and the cumulative contribution rate was 80.177%, revealing that these are useful physiological and biochemical indicators of smut resistance. Subordinate function analysis indicated that the levels of smut resistance of the nine genotypes were (high to low): YZ03-258, FN40, YZ01-1413, GT02-467, ROC22, YZ03-103, YT96-86, FN39, LC05-136, which is similar to the results from copy number determination of smut pathogens. The results suggest that after artificial needle inoculation, rapid identification of physiological resistance to sugarcane smut was achieved based on copy number increases in the sugarcane smut pathogen and the physiological and biochemical changes in sugarcane bud during the early phase of infection.
Collapse
Affiliation(s)
| | | | - Liping Xu
- *Correspondence: Liping Xu, Youxiong Que,
| | | | | | | | | |
Collapse
|
16
|
Abstract
The incidence of dwarf bunt of wheat as a function of inoculum density was studied in a susceptible and a partially resistant cultivar at three disease-conducive locations for three seasons. Prior to seeding, plots were fumigated with methyl bromide to eliminate residual inoculum. Each cultivar was seeded into two 1.2-m rows in four replicates. The soil surface was inoculated with 0, 16 × 102, 16 × 103, 16 × 104, 16 × 105, and 16 × 106 teliospores of Tilletia controversa per row, or seed was inoculated with 0, 2 × 102, 2 × 103, 2 × 104, 2 × 105, and 2 × 106 teliospores per gram. To determine maximum possible infection, two 3.1-m rows of each cultivar were soil-surface inoculated at 10× the highest treatment rate. In the soil-inoculated plots, a minimum of 16 × 103 teliospores/row was needed to cause trace amounts of disease (0.6% maximum), even when the positive indicator treatment had up to 88% incidence. Only trace amounts or no disease occurred below the 16 × 105 rate. In the seed-inoculated plots, infection was rare and occurred only at inoculation rates of 2 × 105 teliospores/g or higher; the highest incidence was 0.4%.
Collapse
Affiliation(s)
- Blair J Goates
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), National Small Grains Germplasm Research Facility, P.O. Box 307, Aberdeen, ID 83210
| | - Gary L Peterson
- USDAARS, Foreign Disease Weed Science Research Unit, 1301 Ditto Ave., Fort Detrick, MD 21702-5023
| |
Collapse
|