Immunity to stripe rust in wheat: A case study of a hypersensitive-response (HR)-independent resistance to Puccinia striiformis f. sp. tritici in Avocet-Yr15

Author(s):  
Hamed (Soren) Seifi ◽  
Mitra Serajazari ◽  
Mina Kaviani ◽  
Peter Pauls ◽  
Helen Booker ◽  
...  
2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Juan Wang ◽  
Yang Wang ◽  
Xinjie Liu ◽  
Yuanliu Xu ◽  
Qing Ma

The plant cytoskeleton, including microtubules and microfilaments, is one of the important factors in determining the polarity of cell division and growth, as well as the interaction of plants with invading pathogens. In defense responses of wheat against the stripe rust (Puccinia striiformisf. sp.tritici) infection, hypersensitive response is the most crucial event to prevent the spread of pathogens. In order to reveal the effect of microtubules on the hypersensitive cell death and H2O2accumulation in the interaction of wheat (Triticum aestivum) cv. Suwon 11 with an incompatible race, CYR23, wheat leaves were treated with microtubule inhibitor, oryzalin, before inoculation. The results showed that the frequency of infection sites with hypersensitive response occurrence was significantly reduced, and hypersensitive cell death in wheat leaves was suppressed compared to the control. In addition, the frequency and the incidence of infected cells with H2O2accumulation were also reduced after the treatment with oryzalin. Those results indicated that microtubules are related to hypersensitive response and H2O2accumulation in wheat induced by the stripe rust, and depolymerization of microtubules reduces the resistance of plants to pathogen infection in incompatible interaction, suggesting that microtubules play a potential role in the expression of resistance of wheat against the stripe rust fungus.


2016 ◽  
Vol 106 (4) ◽  
pp. 362-371 ◽  
Author(s):  
P. Cheng ◽  
X. M. Chen ◽  
D. R. See

Puccinia striiformis causes stripe rust on cereal crops and many grass species. However, it is not clear whether the stripe rust populations on grasses are able to infect cereal crops and how closely they are related to each other. In this study, 103 isolates collected from wheat, barley, triticale, rye, and grasses in the United States were characterized by virulence tests and simple sequence repeat (SSR) markers. Of 69 pathotypes identified, 41 were virulent on some differentials of wheat only, 10 were virulent on some differentials of barley only, and 18 were virulent on some differentials of both wheat and barley. These pathotypes were clustered into three groups: group one containing isolates from wheat, triticale, rye, and grasses; group two isolates were from barley and grasses; and group three isolates were from grasses and wheat. SSR markers identified 44 multilocus genotypes (MLGs) and clustered them into three major molecular groups (MG) with MLGs in MG3 further classified into three subgroups. Isolates from cereal crops were present in one or more of the major or subgroups, but not all, whereas grass isolates were present in all of the major and subgroups. The results indicate that grasses harbor more diverse isolates of P. striiformis than the cereals.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 957
Author(s):  
Parimal Sinha ◽  
Xianming Chen

Barberry (Berberis spp.) is an alternate host for both the stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst), and the stem rust pathogen, P. graminis f. sp. tritici (Pgt), infecting wheat. Infection risk was assessed to determine whether barberry could be infected by either of the pathogens in Asia and Southeastern Europe, known for recurring epidemics on wheat and the presence of barberry habitats. For assessing infection risk, mechanistic infection models were used to calculate infection indices for both pathogens on barberry following a modeling framework. In East Asia, Bhutan, China, and Nepal were found to have low risks of barberry infection by Pst but high risks by Pgt. In Central Asia, Azerbaijan, Iran, Kazakhstan, southern Russia, and Uzbekistan were identified to have low to high risks of barberry infection for both Pst and Pgt. In Northwest Asia, risk levels of both pathogens in Turkey and the Republic of Georgia were determined to be high to very high. In Southwest Asia, no or low risk was found. In Southeastern Europe, similar high or very high risks for both pathogens were noted for all countries. The potential risks of barberry infection by Pst and/or Pgt should provide guidelines for monitoring barberry infections and could be valuable for developing rust management programs in these regions. The framework used in this study may be useful to predict rust infection risk in other regions.


Plant Disease ◽  
2021 ◽  
Author(s):  
Cai Sun ◽  
Yike Liu ◽  
Qiang Li ◽  
Baotong Wang ◽  
Shuhui Chen ◽  
...  

Wheat stripe rust, an airborne fungal disease and caused by Puccinia striiformis Westend. f. sp. tritici (Pst), is one of the most devastating diseases on wheat. It is the most effective and economical measure for the diseases control to identify high-level resistance genes and apply in wheat breeding. Chinese wheat cultivar Xike01015 presents high levels of all stage resistance (ASR) to the current predominant Pst race CYR33. In this study, a single dominant gene, designated as YrXk, was identified in Xike01015 conferring resistance to CYR33 with genetic analysis of F2 and BC1 population from cross of Mingxian169 (susceptible) and Xike01015. The specific length amplified fragment sequencing (SLAF-seq) strategy was used to construct linkage map in the F2 population. QTL analysis mapped YrXk to a 12.4 Mb segment on chromosome1BS, explaining over 86.96% phenotypic variance. Gene annotation in the QTL region identified three differential expressed candidate genes , TraesCS1B02G168600.1, TraesCS1B02G170200.1, and TraesCS1B02G172400.1. The qRT-PCR results displayed that TraesCS1B02G170200.1 and TraesCS1B02G168600.1 significantly up-regulated and down-regulated, respectively, and TraesCS1B02G170200.1 slightly up-regulated after changed with CYR33 in the seedling stage, which indicating these genes may function in wheat resistance to stripe rust. The results of this study can be used in wheat breeding for improving resistance to stripe rust.


Plant Disease ◽  
2021 ◽  
Author(s):  
Mercy Wamalwa ◽  
Ruth Wanyera ◽  
Julian Rodriguez-Algaba ◽  
Lesley Boyd ◽  
James Owuoche ◽  
...  

Stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst), is a major threat to wheat (Triticum spp.) production worldwide. The objective of this study was to determine the virulence of Pst races prevalent in the main wheat growing regions of Kenya, which includes Mt. Kenya, Eastern Kenya, and the Rift Valley (Central, Southern, and Northern Rift). Fifty Pst isolates collected from 1970 to 1992 and from 2009 to 2014 were virulence phenotyped using stripe rust differential sets, and 45 isolates were genotyped with sequence characterized amplified region (SCAR) markers to differentiate among the isolates and identify aggressive strains PstS1 and PstS2. Virulence corresponding to stripe rust resistance genes Yr1, Yr2, Yr3, Yr6, Yr7, Yr8, Yr9, Yr17, Yr25, Yr27 and the seedling resistance in genotype Avocet S were detected. Ten races were detected in the Pst samples obtained from 1970 to 1992, and three additional races were detected from 2009 to 2014, with a single race being detected in both periods. The SCAR markers detected both Pst1 and Pst2 strains in the collection. Increasing Pst virulence was found in the Kenyan Pst population, and that diverse Pst race groups dominated different wheat growing regions. Moreover, recent Pst races in east Africa indicated possible migration of some race groups into Kenya from other regions. This study is important in understanding Pst evolution and virulence diversity and useful in breeding wheat cultivars with effective resistance to stripe rust. Keywords: pathogenicity, Puccinia f. sp. tritici stripe (yellow) rust, Triticum aestivum


2013 ◽  
Vol 35 (3) ◽  
pp. 304-314 ◽  
Author(s):  
K. Kumar ◽  
M. D. Holtz ◽  
K. Xi ◽  
T. K. Turkington

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jan Bettgenhaeuser ◽  
Inmaculada Hernández-Pinzón ◽  
Andrew M. Dawson ◽  
Matthew Gardiner ◽  
Phon Green ◽  
...  

AbstractCrop losses caused by plant pathogens are a primary threat to stable food production. Stripe rust (Puccinia striiformis) is a fungal pathogen of cereal crops that causes significant, persistent yield loss. Stripe rust exhibits host species specificity, with lineages that have adapted to infect wheat and barley. While wheat stripe rust and barley stripe rust are commonly restricted to their corresponding hosts, the genes underlying this host specificity remain unknown. Here, we show that three resistance genes, Rps6, Rps7, and Rps8, contribute to immunity in barley to wheat stripe rust. Rps7 cosegregates with barley powdery mildew resistance at the Mla locus. Using transgenic complementation of different Mla alleles, we confirm allele-specific recognition of wheat stripe rust by Mla. Our results show that major resistance genes contribute to the host species specificity of wheat stripe rust on barley and that a shared genetic architecture underlies resistance to the adapted pathogen barley powdery mildew and non-adapted pathogen wheat stripe rust.


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