关键词: AtNEK6, 烟草, 生长势, 耐旱性, 耐盐性

Abstract:

NEK6 gene encodes a serine/threonine protein kinase that regulates the expression of cell cyclin related genes and ethylene signal transduction, which related to plant stress resistance. In this study, AtNEK6 over-expressed plasmid was constructed and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Three transgenic tobacco lines of T2 generation were recruited and treated with the mannitol and NaCl treatments, which simulating drought and salt conditions. Under normal condition, root length of transgenic plants was longer than that of wild type. Moreover, the lateral root number and leaf fresh weight were also much more than those in wild type. Under the stress conditions, transgenic plants showed enhanced tolerance to drought and salt stresses. The chlorophyll fluorescence parameter (Fv/Fm), SOD and CAT activities, and proline contents in leaves were increased significantly more in transgenic plants compared to those in wild type, whereas the MDA contents of transgenic lines were decreased after stress treatments, which in agreement with that obtained from stress treatments. Therefore, the transgenic tobacco was more tolerant to drought and salt stresses by over-expression of AtNEK6 gene.

Key words: AtNEK6, tobacco, growth potential, drought tolerance, salt tolerance