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ARS Home » Pacific West Area » Pullman, Washington » WHGQ » Research » Publications at this Location » Publication #324525

Research Project: Improved Control of Stripe Rust in Cereal Crops

Location: Wheat Health, Genetics, and Quality Research

Title: Wheat transcription factor TaWRKY70 is positively involved in high-temperature seedling-plant resistance to Puccinia striiformis f. sp. tritici

Author
item Wang, Junjuan - Northwest Agriculture And Forestry University
item Tao, Fei - Northwest Agriculture And Forestry University
item An, Fei - Northwest Agriculture And Forestry University
item Zou, Yiping - Northwest Agriculture And Forestry University
item Tan, Wei - Northwest Agriculture And Forestry University
item Chen, Xianming
item Xu, Xiangming - East Malling Research
item Hu, Xiaoping - Northwest Agriculture And Forestry University

Submitted to: Molecular Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2016
Publication Date: 5/5/2016
Citation: Wang, J., Tao, F., An, F., Zou, Y., Tan, W., Chen, X., Xu, X., Hu, X. 2016. Wheat transcription factor TaWRKY70 is positively involved in high-temperature seedling-plant resistance to Puccinia striiformis f. sp. tritici. Molecular Plant Pathology. doi: 10.1111/mpp.12425.

Interpretive Summary: Stripe rust is a devastating disease of wheat worldwide. Wheat high-temperature seedling-plant (HTSP) resistance to stripe rust is non-race-specific and durable. WRKY transcription factors have proven to play important roles in plant defence responses to attacks by several pathogens, but not studied for HTSP resistance to stripe rust. In this study, we isolated a TaWRKY70 gene from wheat variety Xiaoyan 6. The expression level of TaWRKY70 was notably increased by exposure to high temperature during the initial symptom-expression stage. This gene also exhibited increased expression in the plants treated with ethylene (ET) and salicylic acid (SA), but had reduced expression in the plants treated with methyl jasmonate (MeJA), in addition to slightly induction by heat (40°C) and cold (4°C) stresses. Silencing of TaWRKY70 enhanced susceptibility to stripe rust in the low temperature treatment, while exposing TaWRKY70-silenced plants to the high temperature (HT) during the initial symptom-expression stage resulted in increased resistance to the pathogen, during which the expression of ET- and SA-responsive genes were modulated, but not for the jasmonic acid responsive gene. This was consistent with the observed significant reductions in the length of uredinial pustules, and the increase on the number of necrotic cells on the HT-treated, TaWRKY70-silenced plants. These results indicate that TaWRKY70 is positively involved in the HTSP resistance, during which the SA and ET signalling are probably activated.

Technical Abstract: Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease of wheat (Triticum aestivum) worldwide. Wheat high-temperature seedling-plant (HTSP) resistance to Pst is non-race-specific and durable. WRKY transcription factors have proven to play important roles in plant defence responses to attacks by several pathogens. However, there is little direct evidence showing that WRKY transcription factors play any role associated with HTSP resistance to Pst. In this study, we isolated a WRKY70 gene, named TaWRKY70, from wheat cultivar Xiaoyan 6. The expression level of TaWRKY70 was notably increased by exposure to high temperature during the initial symptom-expression stage of Pst infection. This gene also exhibited increased expression in the plants treated with ethylene (ET) and salicylic acid (SA), but had reduced expression in the plants treated with methyl jasmonate (MeJA), in addition to slightly induction by heat (40°C) and cold (4°C) stresses. Silencing of TaWRKY70 enhanced susceptibility to Pst in the low temperature treatment, while exposing TaWRKY70-silenced plants to the high temperature (HT) during the initial symptom-expression stage of Pst infection resulted in increased resistance to the pathogen, during which the expression of ET- and SA-responsive genes TaPIE1 and TaPR1.1 were modulated, but not for jasmonic acid (JA) responsive gene TaAOS. This was consistent with the observed significant reductions in the length of uredinial pustules, and the increase on the number of necrotic cells on the HT-treated, TaWRKY70-silenced plants. These results indicate that TaWRKY70 is positively involved in the HTSP resistance, during which the SA and ET signalling are probably activated.