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

摘要：

NEK6基因编码一种丝/苏氨酸蛋白激酶,具有调控植物细胞周期蛋白基因表达和乙烯信号转导的功能,与植物抵抗逆境胁迫相关。将拟南芥AtNEK6基因导入烟草,利用甘露醇和NaCl模拟干旱和盐胁迫环境对T2代转基因烟草进行研究。结果表明,在无胁迫处理条件下,转基因烟草根长、侧根数和鲜重显著高于野生型；在干旱和盐胁迫条件下,转基因烟草根长、侧根数和鲜重均极显著高于野生型,表现出较强的耐旱耐盐性；胁迫处理的转基因烟草叶片叶绿素荧光参数值(Fv/Fm)、SOD和CAT活性以及Pro含量极显著高于野生型,MDA含量极显著低于野生型,进一步证明了AtNEK6基因能够促进烟草的生长和提高转基因烟草对于干旱与盐碱的抵抗能力。

关键词: AtNEK6, 烟草, 生长势, 耐旱性, 耐盐性