热激转录因子AtHsfA9在转基因烟草中的功能分析

Functional analysis of heat stress transcriptional factor AtHsfA9 in transgenic nicotiana tabacum

目的研究拟南芥热激转录因子AtHsfA9在转基因烟草中的抗高温能力。方法从拟南芥基因组中克隆了热激转录因子AtHsfA9,利用种子特异启动子At2S3构建了超表达载体At2S3::AtHsfA9并转化烟草,得到转基因烟草纯合株系。对野生型拟南芥进行45℃热激处理,对比未作处理的野生型(WT)拟南芥,观察热激转录因子AtHsfA9的表达量。同时对转基因烟草进行45℃胁迫处理,对照野生型烟草观察其根长变化。结果对野生型拟南芥进行45℃热激处理0.5h,1h,2h,3h,4h和5h后,热激转录因子AtHsfA9的表达量与未作处理的WT相比分别上升了4.5,6.2,15.0,34.6,27.0和10.4倍,说明热激转录因子AtHsfA9响应高温胁迫。对转基因烟草进行45℃胁迫处理12h,结果显示,与WT相比,经过热激处理的At2S3::AtHsfA9转基因株系的根长差异要小。结论热激转录因子AtHsfA9在转基因烟草中具有提高作物的抗高温能力。

Objective： To evaluate high temperature resistant ability of the Arabidopsis heat shock transcription factor AtHsfA9 in transgenic tobacco. Methods： A genomic fragment containing the ORF of Arabidopais heat shock transcription factor （AtHsfA9） was cloned by PCR amplification, and homozygous transgenic tobacco lines over expressing the construct At2S3 ：AtHsfA9 with the seed s 文章编号： 1004-7115 （2013） 08-0561-04peeifie promoter At2S3 were generated. At 45℃ heat shock treatment of wild type Arabidopsis, the expression of heat shock transcription factor AtHsfA9was observed and the changes of root length were observed. Results： In Arabidopsis, after treatment under 45℃ for 0.5h, lh, 2h, 3h, 4h and 5h, the expression level of AtHsfA9 was induced 4.5, 6.2, 15.0, 34.6, 27.0 and 10.4-fold compared with WT, respoctively, indicating that AtHsfA9 was responsive to heat stress. In tobacco, after treatment under 45℃ for 12h, compared with WT, the difference of root length of At2S3 ： ：AtHsfA9 transgenic lines was lower, indicating that At2S3 ： ：AtHsfA9 transgenie lines showed resistance to heat stress. Conclusion： These results suggest that, the heat shock transcription factor AtHsfA9 has the capacity of improving the resistance to high temperature of crop seeds in transgenic tobacco.