Functional Analysis of Photo-Oxidative Stress Responsive Genes in Wheat Using Virus-Induced Gene Silencing System

Abstract

Functional analysis of photo-oxidative stress responsive genes in wheat(Triticum aestivum L.) may benefit wheat improvement for high radiation use efficiency. A Chinese variety Xiaoyan 54 developed from distant hybridization between common wheat(T. aestivum, 2n=42) and tall wheatgrass(Thinopyrum ponticum, 2n=70) shows significant tolerance to high light induced photo-oxidative stress. Based on previous transcriptome analysis of Xiaoyan 54 in response to high light stress, six genes were selected in this study to assess their possible roles in photo-oxidative stress response using barley stripe mosaic virus(BSMV) mediated virus-induced gene silencing(VIGS) system in Xiaoyan 54. The BSMV induced silencing of the targeted genes together with the BSMV:GFP control plants were exposed to low temperature and high light(LTHL), N-(3,4-dichlorophenyl)-N',N'- dimethylurea(DCMU), methylviologen(MV), and hydrogen peroxide(H2O2) stress, respectively. The maximum photochemical efficiency of photosystem II(F v/F m), the photosynthetic performance index(P.I.), malondialdehyde(MDA) content, and biomass were evaluated. The results showed that Ta23008 and Ta92165 were involved in the responses of wheat to LTHL, DCMU, MV, and H2O2, respectively. Ta106078 was responsible for wheat tolerance to DCMU, MV, and H2O2 while Ta27787 was responsible for LTHL, DCMU, and H2O2 stress. Ta24695 participated in the response of wheat to both LTHL and H2O2. However, Ta119251 seemed to be only responsible for the DCMU stress in wheat. Additionally, four genes, Ta23008, Ta92165, Ta106078, and Ta119251, were likely to regulate biomass accumulation because the biomass was significantly reduced when they were silenced in wheat. These results provided new hints toward understanding the molecular mechanism of tolerance to photo-oxidative stress in Xiaoyan 54.