Overexpression of VvASMT1 from grapevine enhanced salt and osmotic stress tolerance in Nicotiana benthamiana

• Published in: PloS one 2022-06, Vol.17 (6), p.e0269028-e0269028
• Main Authors: Yu, Yanyan, Ni, Yong, Qiao, Tian, Ji, Xiaomin, Xu, Jinghao, Li, Bo, Sun, Qinghua
• Format: Article
• Language: English
• Subjects: Abiotic stress; Analysis; Antioxidants; Apoptosis; Biology and Life Sciences; Biosynthesis; Drought; Drought damage; Droughts; Ecology and Environmental Sciences; Ectopic expression; Engineering and Technology; Environmental conditions; Enzymes; Evaluation; Experiments; Flowers & plants; Gene expression; Gene Expression Regulation, Plant; Genes; Genetic aspects; Genetic engineering; Genetically modified plants; Germination; Grapes; Grapevines; Melatonin; Melatonin - metabolism; Methyltransferase; Moisture content; N-Acetylserotonin; Nicotiana; Nicotiana benthamiana; Osmotic Pressure - physiology; Osmotic stress; Oxygen; Pattern analysis; Physical Sciences; Physiology; Plant growth; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified - metabolism; Reactive oxygen species; Research and Analysis Methods; Salinity; Salt Tolerance - genetics; Salts; Seeds; Serotonin; Sodium Chloride - pharmacology; Stress response; Stress, Physiological - genetics; Stresses; Transgenic plants; Water content; Wilting
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0269028

Salt and drought stresses are major environmental conditions that severely limit grape growth and productivity, while exogenous melatonin can alleviate the drought and salt damage to grapevines. N-acetylserotonin methyltransferase (ASMT) is the key enzyme in melatonin synthesis, which plays a critical role in regulating stress responses. However, the roles of ASMTs from grapevine under drought and salt stresses responses remain largely unclear. In this study, the VvASMT1 gene was isolated from grapevine, and its physiological functions in salt and mimic drought stress tolerance were investigated. Expression pattern analysis revealed that VvASMT1 was significantly induced by different salt and osmotic stresses. Ectopic expression of VvASMT1 in Nicotiana benthamiana significantly enhanced melatonin production in transgenic plants. Compared with wild-type plants, the transgenic lines exhibited a higher germination ratio, longer root length, lower degree of leaf wilting and relative water content (RWC) under salt and osmotic stresses. In addition, under salt and osmotic stresses, overexpression of VvASMT1 improved proline and malondialdehyde (MDA) contents, increased the activity of antioxidant enzymes and decreased the accumulation of reactive oxygen species (ROS). Taken together, our results demonstrate the explicit role of VvASMT1 in salt and osmotic stress responses, which provides a theoretical foundation for the genetic engineering of grapevine.