NtabEXPA12基因过表达对烟草叶片发育及抗逆性的影响

Overexpression of NtabEXPA12 Affects Leaf Development and Abiotic Stress Tolerance in Tobacco

细胞壁松弛因子膨胀素在调控植物生长发育和响应非生物胁迫等方面发挥重要作用,克隆烟草膨胀素基因并研究其功能可为烟草叶片发育调控和抗逆育种提供理论依据。本研究从普通烟草K326中克隆了一个膨胀素基因NtabEXPA12及其启动子ProNtabEXPA12,通过实时荧光定量PCR、亚细胞定位和过表达等对该基因进行了功能研究,分析了启动子包含的顺式作用元件和活性。结果表明,NtabEXPA12在烟草叶片中具有较高的表达量;ProNtabEXPA12中包含多个响应高盐、干旱和植物激素的顺式元件,并且其活性受到高盐、干旱和ABA等的诱导;过表达NtabEXPA12通过调控细胞扩展促进转基因烟草叶片的生长发育,并可以提高转基因K326对高盐和干旱的抗性。因此,NtabEXPA12在烟草叶片发育调控及抗逆育种中具有潜在的应用前景。

Expansins play important roles in plant growth and development and plant’s responses to abiotic stresses.Cloning and studying the functions of tobacco expansin genes will provide a theoretical basis for regulation of tobacco leaf development and tobacco resistance breeding.In this study,we cloned NtabEXPA12 with its promoter ProNtabEXPA12 from tobacco variety K326,studied its function by qPCR,subcellular localization and gene overexpression assays,and analyzed cis-regulatory elements in ProNtabEXPA12 and its promoter activity.The results showed that NtabEXPA12 was highly expressed in tobacco leaves.Various cis-elements in ProNtabEXPA12 were identified which were related to plant’s responses to salt,drought and plant hormones.And indeed,the activity of ProNtabEXPA12 was strongly induced by NaCl,ABA and drought treatments.We also found that overexpression of NtabEXPA12 promoted cell and leaf expansion,and enhanced abiotic stress tolerance in transgenic K326 plants.Therefore,NtabEXPA12 has potential application values in manipulating tobacco leaf development and tobacco resistance breeding.