Overexpression of the Melatonin Synthesis-Related Gene Improves the Resistance of Tomato to Salt Stress.

Melatonin can increase plant resistance to stress, and exogenous melatonin has been reported to promote stress resistance in plants. In this study, a melatonin biosynthesis-related gene was cloned from tomato ( Mill. cv. ), which is highly expressed in fruits compared with other organs. The protein was found to locate in the cytoplasm. Melatonin content in overexpression transgenic tomato plants was significantly higher than that in wild-type plants. Under 800 mM NaCl stress, the transcript level of in tomato leaf was positively related to the melatonin contents. Furthermore, compared with that in wild-type plants, levels of superoxide and hydrogen peroxide were lower while the content of proline was higher in transgenic tomatoes. Therefore, was closely associated with melatonin biosynthesis confers the significant salt tolerance, providing a clue to cope with the growing global problem of salination in agricultural production.