Effect of seed priming with zinc, iron and selenium on the low temperature tolerance of Nicotiana tabacum L. during seed germination

Tobacco is one of the important cash crops in China. It is sensitive to low temperature, especially in the early stage of tobacco seed germination and seedling growth. Low temperature stress directly affects the germination of tobacco seeds, leading to irregular emergence and slow growth of seedlings. Therefore, it is important to improve the vigor and cold tolerance of tobacco. In this study, two cold-sensitive tobacco varieties were primed individually with ZnSO4, FeSO4 and Na2SeO3 to test the effects of different microelements priming on seed germination. The results showed that under low temperature (11 degrees C), all three elements could improve tobacco seed vigor and promote seed germination, with selenium priming exhibiting the best effect. Selenium priming significantly increased the seed vigor index of YY97 by 29.60 % and of YY85 by 47.57 %. Moreover, selenium priming could effectively enhance POD activity in seeds, promote the oxidation of phenolic substances and enhance the activities of G-6-PDH and 6-P-GDH in the process of scavenging ROS and converting H2O2 to center dot O-2(-). The results suggested that selenium played an important role in promoting tobacco seed germination under low temperature.