A rice mutant defective in antioxidant-defense system and sodium homeostasis possesses increased sensitivity to salt stress

作者：Lin K C; Jwo W S; Chandrika N N P; Wu T M; Lai M H; Wang C S; Hong C Y^*

来源：Biologia Plantarum, 2016, 60(1): 86-94.

DOI：10.1007/s10535-015-0561-7

• catalase
• chlorophyll fluorescence
• hydrogen peroxide
• Oryza sativa
• oxidative stress
• salt hypersensitive mutant
• superoxide dismutase

Screening salt-sensitive mutants is a powerful method to identify genes associated with salt tolerance. We used forward genetic screening with sodium azide-mutated rice (Oryza sativa L. cv. Tainung 67) to identify mutants showing hypersensitivity to salt stress. A new mutant line, named salt hypersensitive 1 (shs1) and exhibiting a severe salt-sensitivity when grown under a high NaCl concentration, was identified; the salt hypersensitivity was caused by duplicate recessive epistasis with mutations likely in two different loci. The shs1 salt sensitive phenotypes included a decreased seed germination rate, reduced shoot height and root length, severe and quick wilting, and overaccumulation of sodium ions in shoots as compared with wild-type plants. In addition, shs1 showed a decreased photosynthetic efficiency and enhanced hydrogen peroxide (H2O2) production under the salt stress. An increased superoxide dismutase activity and decreased catalase activity were responsible for the hyperaccumulation of H2O2 in shs1. The hypersensitivity of shs1 to the salt stress might be caused by an impaired antioxidant machinery and cellular Na+ homeostasis.

• 出版日期2016-1