Investigation of the mechanism of adult-stage resistance to barley yellow dwarf virus associated with a wheat–Thinopyrum intermedium translocation

• Main Authors: Xindong Wang, Wei Rong, Yan Liu, Xifeng Wang, Zengyan Zhang
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2018-08-01
• Series: Crop Journal
• Online Access: http://www.sciencedirect.com/science/article/pii/S2214514118300254

Barley yellow dwarf virus (BYDV) can infect wheat (Triticum aestivum L.), leading to yield loss. Among four BYDV strains (GAV, GPV, PAV, and RMV) identified in China, BYDV-GAV is the prevailing isolate. YW642, a wheat–Thinopyrum intermedium translocation line, is resistant to BYDV isolates at both seedling and adult stages. Zhong 8601 is the wheat recurrent parent of YW642 and is susceptible to BYDV. In this study, we investigated the adult-stage resistance mechanism of YW642, measured BYDV titer and hydrogen peroxide (H2O2) in adult-stage leaves of YW642 and Zhong 8601 inoculated with BYDV-GAV, and identified transcriptional differences between YW642 and Zhong 8601 using microarray-based comparative transcriptomics. Enzyme-linked immunosorbent assay and H2O2 assay showed that both BYDV titer and H2O2 content were markedly lower in YW642 than in Zhong 8601 at 21, 28, 35, and 40 days post-inoculation (dpi). The transcriptomic comparison revealed that many types of genes were significantly up-regulated at 35 dpi in adult-stage leaves of YW642 compared to Zhong 8601. The important up-regulated genes associated with the adult-stage resistance encoded 15 resistance-like proteins, pathogenesis-related proteins (such as defensin and lipid transfer proteins), protein kinase homologs, transcription factors, reactive oxygen species scavenging-related proteins, and jasmonic acid and gibberellic acid biosynthesis enzymes. These results suggest that precise expression regulation of these proteins plays a crucial role in adult-stage resistance of YW642 against BYDV infection. Keywords: Barley yellow dwarf virus, Reactive oxygen species, Resistance at adult stage, Defense-associated genes, Phytohormone