<i>SlSAMS1</i> improves carbon and nitrogen metabolism in tomato under salt stress

Salt stress limits plant growth and development of tomato (<italic>Solanum lycopersicum</italic>). <italic>S</italic>-adenosyl methionine synthetase (SAMS) plays a pivotal role in response to salt stress in plants, however, its mechanism for regulating carbon and nitrogen metabolism in this process is not fully understood. Herein, we found that <italic>SlSAMS1</italic>, a <italic>SAMS</italic> homologous gene in tomato, enhances salt tolerance throughout the entire lifecycle of tomato plants. Salt stress inhibits carbon and nitrogen metabolism in tomato plants, while overexpression of the <italic>SlSAMS1</italic> gene maintains high levels of energy metabolism, as evidenced by increased nitrogen contents, sugar contents, and enzyme activities related to carbon and nitrogen metabolism during salt stress, thus ensuring better growth and development under salt stress in tomato.