独行菜种子DREB类转录因子家族及LaDREB表达对幼苗冷胁迫响应

DREB Transcription Factor Family in Lepidium apetalum Willd. Seeds and Response of LaDREB Expression in Seedling to Cold Stress

DREB是广泛存在于植物中的一类重要的转录因子,其调控一些参与非生物胁迫相关基因的表达,在植物抗逆方面起重要作用。本研究在转录组数据基础上,比较了独行菜(Lepidium apetalum Willd.)种子在实验室条件耐受和不能耐受低温萌发的两组样本,对其DREB转录因子家族成员进行了分析,并对该家族成员表达差异极显著的基因LaDREB进行了克隆、序列分析、结构预测,研究了其表达在独行菜幼苗中对低温胁迫的响应。结果表明,萌发中的独行菜种子,至少有13个DREB转录因子表达,相对于低温萌发停滞组,在低温萌发耐受组的独行菜种子中,有1个下调、10个上调、2个表达差异不显著。其中表达量最显著上调的c18023_g1序列,包含639 bp的开放阅读框,功能注释到DREB类基因,与宽叶独行菜LiDREB序列一致性最高,因此该基因命名为LaDREB。其编码210 aa的蛋白质、具有典型AP2结构域、分子式为C1927H3217N639O815S124、理论等电点为5.18、分子量为52.352 9 k D。定量表达分析表明,LaDREB在独行菜幼苗期,经低温处理后,其表达量快速显著上调,表明LaDREB可能在独行菜幼苗抵抗低温胁迫中起调控作用,为深入探讨LaDREB转录因子在独行菜幼苗耐受低温中的作用提供理论参考。

DREB is an important transcription factor widely existing in plants,which regulates the expression of some genes involved in abiotic stresses and plays an important role in plant stress tolerance.On the basis of transcriptome data,the expression of DREBs between the two groups seeds of Lepidium apetalum which could tolerate low temperature germination and not were compared in this experiment.The members in DREB transcription factors family were analyzed,and LaDREB gene,whose relative level of expression was the most different one between the two-group seeds,was cloned.Also,its sequence was analyzed,its structure was predicted,and the response of its expression in seedling of L. apetalum to cold stress was studied.The results showed that there were at least 13 family members of DREB transcription factors in L. apetalum seeds.Compared with the low temperature germination stagnation group,there were 1 down regulation,10 up regulation and 2DREB transcription factors with no significant difference in the low temperature germination tolerance group seeds.Among them,the expression of c18023_g1 was up-regulated remarkably,and it had an open reading frame of 639 bp.DREB class genes were obtained after functional annotation,which was in the highest consistency with LiDREB sequence of Lepidium latifolium,therefore it was named as LaDREB.LaDREB encoded a protein of 210 aa,owning the typical domain of AP2.Its molecular formula waswith the theoretical p I of 5.18and the molecular weight of 52.352 9 k D.Quantitative expression analysis indicated that after cold stress,the expression of LaDREB in seedling of L. apetalum increased significantly,suggesting that LaDREB might play the regulating role in the response of L. apetalum seedling to cold stress,which could provide theoretical reference for the further study on the effect of LaDREB transcription factor on the tolerance of L. apetalum seedling under low temperature.