Overexpression of S‐adenosyl‐l‐methionine synthetase increased tomato tolerance to alkali stress through polyamine metabolism. Issue 6 (7th March 2014)

• Record Type: Journal Article
• Authors: Gong, Biao; Li, Xiu; VandenLangenberg, Kyle M.; Wen, Dan; Sun, Shasha; Wei, Min; Li, Yan; Yang, Fengjuan; Shi, Qinghua; Wang, Xiufeng
• Is Part Of: Plant biotechnology journal. Volume 12:Issue 6(2014:Aug.)
• Page Start: 694
• Page End: 708
• Publication Date: 2014-03-07
• Subjects: Plant biotechnology -- Periodicals; Plant genetic engineering -- Periodicals; 630.272
• DOI: 10.1111/pbi.12173
• Languages: English
• ISSNs: 1467-7644

Abstract

<abstract abstract-type="main" id="pbi12173-abs-0001"> <title>Summary</title> <p>S‐adenosyl‐<sc>l</sc>‐methionine (SAM) synthetase is the key enzyme involved in the biosynthesis of SAM, which serves as a common precursor for polyamines (PAs) and ethylene. A SAM synthetase cDNA (<italic>SlSAMS1</italic>) was introduced into the tomato genome using the <italic>Agrobacterium tumefaciens</italic> transformation method. Transgenic plants overexpressing <italic>SlSAMS1</italic> 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 <italic>in vivo</italic> and <italic>in vitro</italic> experiments indicated that the function of <italic>SlSAMS1</italic> mainly depended on the accumulation of Spd and Spm in the transgenic lines. A grafting experiment showed that rootstocks from <italic>SlSAMS1</italic>‐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 <italic>SlSAMS1</italic> positively regulates tomato tolerance to alkali stress and plays a major role in modulating polyamine metabolism, resulting in maintainability of nutrient and ROS balance.</p> </abstract>