Monodehydroascorbate reductase gene, regulated by the wheat PN-2013 miRNA, contributes to adult wheat plant resistance to stripe rust through ROS metabolism

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• 作者：Hao Feng ; Xiaojie Wang ; Qiong Zhang ; Yanping Fu ; Chuanxin Feng ; Bing Wang ; Lili Huang ; Zhensheng Kang
• 关键词：APR ; adult plant resistance ; APX ; ascorbate peroxidase ; AsA&ndash ; GSH cycle ; ascorbate&ndash ; glutathione cycle ; CAT ; catalase ; CYR32 ; Chinese yellow rust 32 ; DHAR ; dehydroascorbate reductase ; dpvi ; days post virus inoculation ; hpi ; hours post inoculation ; MDHAR ; monodehydroascorbate reductase ; miRNA ; microRNA ; PCD ; programmed cell death ; qRT-PCR ; quantitative real time polymerase chain reaction ; ROS ; reactive oxygen species ; RT-PCR ; reverse transcription polymerase chain reaction ; SOD ; superoxid
• 刊名：Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms
• 出版年：January, 2014
• 年：2014
• 卷：1839
• 期：1
• 页码：1-12
• 全文大小：1400 K

文摘

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive wheat diseases worldwide. Varieties with adult plant resistance (APR) maintain effective and durable disease resistance. APR to stripe rust in wheat cultivar XZ9104 (XZ) is associated with extensive hypersensitive cell death and production of reactive oxygen species in the host. MDHAR is an important gene in the AsA-GSH cycle, and it plays an important role in maintaining the reduced pool of AsA scavenging hydrogen peroxide. microRNAs (miRNAs) were shown to engage in post-transcriptional regulation by degrading target mRNAs or repressing gene translation in plants responding to abiotic/biotic stresses. Previously, two novel miRNAs (1136-P3 and PN-2013) were isolated in wheat and the target gene of them was determined using degradome sequencing technology. In this study, the target gene was isolated and characterized as TaMDHAR, a monodehydroascorbate reductase gene. We first demonstrated that the target gene could be cleaved by these two miRNAs in tobacco leaves experimentally. However, TaMDHAR was regulated by PN-2013, not 1136-P3, in wheat-Pst adult incompatible interaction according to the expression patterns. The TaMDHAR knockdown resulted in improved wheat resistance to Pst at the seedling stage, with no influence on 1136-P3 and PN-2013 expression. The TaMDHAR knockdown resulted in a much greater H₂O₂ accumulation and lower APX and CAT activities together with higher expression in several PR genes. We deduced that TaMDHAR could contribute to the APR of XZ through ROS metabolism as regulated by the AsA-GSH cycle.