Overexpression of tomato SIGGP-LIKE gene improves tobacco tolerance to methyl viologen-mediated oxidative stress

Ascorbate (AsA) is very important in scavenging reactive oxygen species in plants. AsA can reduce photoinhibition by xanthophyll cycle to dissipate excess excitation energy. GGP is an important enzyme in AsA biosynthesis pathway in higher plants. In this study, we cloned a gene, SIGGP-LIKE, that has the same function but different sequence compared with SIGGP. The function of SIGGP-LIKE gene in response to oxidative stress was investigated using transgenic tobacco plants overexpressed SIGGP-LIKE under methyl viologen treatment. After oxidative stress treatment, transgenic tobacco lines exhibited higher levels of reduced AsA content and APX activity than WT plants. Under oxidative stress, transgenic tobacco plants accumulated less ROS and exhibited lower degrees of REC and MDA. Consequently, relatively higher levels of Pn, Fv/Fm, de-epoxidation status of xanthophyll cycle and D1 protein were maintained in transgenic tobacco plants. Hence, overexpression of SIGGP-LIKE gene enhances AsA biosynthesis and can alleviate the photoinhibition of PSII under oxidative stress. (C) 2016 Elsevier GmbH. All rights reserved.