Open AccessOverexpression of S‐adenosyl‐ l ‐methionine synthetase increased tomato tolerance to alkali stress through polyamine metabolism
Author(s) -
Gong Biao,
Li Xiu,
VandenLangenberg Kyle M.,
Wen Dan,
Sun Shasha,
Wei Min,
Li Yan,
Yang Fengjuan,
Shi Qinghua,
Wang Xiufeng
Publication year - 2014
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12173
Subject(s) - biology , polyamine , biochemistry , polyamine oxidase , transformation (genetics) , methionine , glutamine synthetase , transgene , enzyme , microbiology and biotechnology , spermine , amino acid , gene , glutamine
Summary S‐adenosyl‐ l ‐methionine ( SAM ) synthetase is the key enzyme involved in the biosynthesis of SAM , which serves as a common precursor for polyamines ( PA s) and ethylene. A SAM synthetase cDNA ( SlSAMS1 ) was introduced into the tomato genome using the Agrobacterium tumefaciens transformation method. Transgenic plants overexpressing SlSAMS1 exhibited a significant increase in tolerance to alkali stress and maintained nutrient balance, higher photosynthetic capacity and lower oxidative stress compared with WT lines. Both in vivo and in vitro experiments indicated that the function of SlSAMS1 mainly depended on the accumulation of Spd and Spm in the transgenic lines. A grafting experiment showed that rootstocks from Sl SAMS 1 ‐overexpressing plants provided a stronger root system, increased PAs accumulation, essential elements absorption, and decreased Na + absorption in the scions under alkali stress. As a result, fruit set and yield were significantly enhanced. To our knowledge, this is the first report to provide evidence that Sl SAMS 1 positively regulates tomato tolerance to alkali stress and plays a major role in modulating polyamine metabolism, resulting in maintainability of nutrient and ROS balance.