外源多胺对红椿S-腺苷甲硫氨酸脱羧酶基因表达的调节作用

Gene cloning and expression analysis of TcSAMDC of Toona ciliata

以2年生红椿家系盆栽幼苗为实验材料,开展了外源多胺对红椿干旱胁迫下TcSAMDC基因表达的修复效应研究。实验设置了轻度、中度和重度3种干旱胁迫梯度,干旱结束后,喷施了1 mmol/L的外源腐胺(Put)、亚精胺(Spd)及精胺(Spm)溶液作为修复处理,旨在探索湖南本土珍贵树种红椿Toona ciliata在遭受季节性干旱胁迫后的生理变化以及有效修复措施。结果表明:1)成功克隆了红椿S-腺苷甲硫氨酸脱羧酶(Tc SAMDC)基因片段,测序得到一条532碱基对的DNA。2)外源Put、Spd和Spm溶液对不同程度干旱胁迫下红椿Tc SAMDC基因表达的修复效果都非常显著(α=0.01)。3)3种外源多胺在不同程度干旱胁迫下对红椿叶片的Tc SAMDC基因表达表现出不同的修复调节作用,其中以外源Spd效果最佳。因此,人为施加外源多胺能在很大程度上影响红椿TcSAMDC基因的表达,进而影响植株的干旱修复能力。采用人工喷施外源多胺诱导Tc SAMDC基因表达,于对抗干旱胁迫具有极强的实际操作意义。

Using two-year-old potted seedlings of Toona ciliata families as experimental materials,a study on the repair effect of exogenous polyamines on TcSAMDC gene expression under drought stress was carried out.The drought stress gradients was set out with3levels:mild,moderate and severe drought stress.After the drought stress,the three exogenous polyamines solutions such as1mmol/L of Put,1mmol/L Spd and1mmol/L Spm were sprayed as the three remediation treatments.The purpose of the experiments is to explore the physiological changes and the effective restoration measures of Hunan native precious tree species T.ciliata after suffering from seasonal drought stress.The results as follows:1)A gene fragment of S-adenosylmethionine decarboxylase(TcSAMDC)from T.ciliate was successfully cloned,and sequenced,thus obtaining the gene fragment’s DNA with532base-pairs.2)The remediation effects of exogenous Put,Spd and Spm solution on TcSAMDC gene expression of T.ciliata under different drought stress were all very significant(a=0.01).3)Three exogenous polyamines showed different repair and regulation effects on TcSAMDC gene expression in Toona sinensis leaves under different degrees of drought stress,among them exogenous Spd performed the best.Therefore,the artificial application of exogenous polyamines can greatly affect the expression of TcSAMDC gene in T.ciliata,and then improve the ability of plant repairing drought stress,and artificial spraying of exogenous polyamines can induce TcSAMDC gene expression,which is of great practical significance in against drought stress.