Virulence Genes of the Wheat Powdery Mildew Fungus,Erysiphe graminisf. sp.tritici,in North Carolina

Plant Disease ◽  
1985 ◽  
Vol 69 (10) ◽  
pp. 905e ◽  
Author(s):  
S. Leath
2011 ◽  
Vol 57 (3) ◽  
pp. 211-216 ◽  
Author(s):  
Jie Feng ◽  
Feng Wang ◽  
Geoff R. Hughes ◽  
Susan Kaminskyj ◽  
Yangdou Wei

The activity of esterase secreted by conidia of wheat powdery mildew fungus, Blumeria graminis f. sp. tritici, was assayed using indoxyl acetate hydrolysis, which generates indigo blue crystals. Mature, ungerminated, and germinating conidia secrete esterase(s) on artificial media and on plant leaf surfaces. The activity of these esterases was inhibited by diisopropyl fluorophosphate, which is selective for serine esterases. When conidia were inoculated on wheat leaves pretreated with diisopropyl fluorophosphate, both appressorial germ tube differentiation and symptom development were significantly impaired, indicating an important role of secreted serine esterases in wheat powdery mildew disease establishment.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Qingping Zhou ◽  
Lingli Li ◽  
Long Wang

Wheat powdery mildew (WPM), caused by Blumeria graminis f.sp. tritici, is a significant disease of wheat throughout the world and has resulted in substantial yield and economic losses in wheat production. It is particularly important to understand the population distribution and genetic resistance of B. graminis f.sp. tritici. In 2019, the cumulative incidence of wheat powdery mildew in China was nearly 8.7 million hm2, which seriously affected the safe production of wheat in China. However, the proportion of disease-resistant wheat varieties in actual production was relatively low, and effective disease-resistant genes were lacking. As one of the main wheat-producing provinces in China, it is of great significance for normal wheat production to understand powdery mildew resistance in Hebei province. In this study, using wheat seedling culture in vitro, the physiological races of wheat powdery mildew in central Hebei province were identified, and the population toxicity frequency was analyzed. The results were as follows: (1) 36 strains were purified and 20 physiological races were identified. Among them, the dominant race is 015, and the distribution frequency is 16.7%. Race 077 is the second dominant race. (2) The frequency of virulence genes VEra, V8, V1, V3c, and V3f in population toxicity frequency analysis was more than 70%, while the frequency of virulence genes V2, MID, V20, V21, V4b, and V4 was less than 16.7%, and 46% of virulence genes of powdery mildew were higher than 40%. It shows that the virulence gene frequency of powdery mildew in Hebei province is high, and the varieties containing Pm2 + MID, Pm20, Pm21, Pm1b, Pm1, and other disease resistance genes have a certain value inbreeding.


2021 ◽  
Author(s):  
Deshan Xie ◽  
Xuewei Cai ◽  
Chunping Yang ◽  
Linjun Xie ◽  
Guangwei Qin ◽  
...  

Genetics ◽  
2020 ◽  
Vol 217 (2) ◽  
Author(s):  
Antony V E Chapman ◽  
Matthew Hunt ◽  
Priyanka Surana ◽  
Valeria Velásquez-Zapata ◽  
Weihui Xu ◽  
...  

Abstract Barley (Hordeum vulgare L.) Mla (Mildew resistance locus a) and its nucleotide-binding, leucine-rich-repeat receptor (NLR) orthologs protect many cereal crops from diseases caused by fungal pathogens. However, large segments of the Mla pathway and its mechanisms remain unknown. To further characterize the molecular interactions required for NLR-based immunity, we used fast-neutron mutagenesis to screen for plants compromised in MLA-mediated response to the powdery mildew fungus, Blumeria graminis f. sp. hordei. One variant, m11526, contained a novel mutation, designated rar3 (required for Mla6 resistance3), that abolishes race-specific resistance conditioned by the Mla6, Mla7, and Mla12 alleles, but does not compromise immunity mediated by Mla1, Mla9, Mla10, and Mla13. This is analogous to, but unique from, the differential requirement of Mla alleles for the co-chaperone Rar1 (required for Mla12 resistance1). We used bulked-segregant-exome capture and fine mapping to delineate the causal mutation to an in-frame Lys-Leu deletion within the SGS domain of SGT1 (Suppressor of G-two allele of Skp1, Sgt1ΔKL308–309), the structural region that interacts with MLA proteins. In nature, mutations to Sgt1 usually cause lethal phenotypes, but here we pinpoint a unique modification that delineates its requirement for some disease resistances, while unaffecting others as well as normal cell processes. Moreover, the data indicate that the requirement of SGT1 for resistance signaling by NLRs can be delimited to single sites on the protein. Further study could distinguish the regions by which pathogen effectors and host proteins interact with SGT1, facilitating precise editing of effector incompatible variants.


2021 ◽  
Vol 693 (1) ◽  
pp. 012124
Author(s):  
Jinling Zhao ◽  
Guomin Chu ◽  
Hao Yan ◽  
Lei Hu ◽  
Yongan Xue

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