Downregulated expression of inhibits photosynthetic activity in bread wheat ( L.).

Deg proteases play critical roles in photoprotection and PSII-repair circle, which remains elusive in cereal crops including wheat. Here, a Deg7-encoding gene was silenced in wheat a -induced gene-silencing system (BSMV-VIGS). When the expression level of was downregulated, the photosynthetic activity including CO assimilation rate, actual photochemical efficiency of PSII, and electron transport rate declined while the nonphotochemical quenching increased significantly. When grown in high light, the plants accumulated more soluble sugar, malondialdehyde, and superoxide anion but had lower superoxide dismutase activity and less ascorbic acid. Additionally, the expression levels of and were repressed in the plants in high light. The plants also were more sensitive to high-light stress. Collectively, it appeared that may be a potential target for wheat radiation-use efficiency improvement against high light stress.