Transcriptional activation of Cor/Lea genes and increase in abiotic stress tolerance through expression of a wheat DREB2 homolog in transgenic tobacco
Transcriptional activation of Cor/Lea genes and increase in abiotic stress tolerance through expression of a wheat DREB2 homolog in transgenic tobacco
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DOI：
10.1007/s11248-007-9158-z
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发表时间：
2008-10-01
影响因子：
3
通讯作者：
Takumi, Shigeo
中科院分区：
文献类型：
--
作者：
Kobayashi, Fuminori;Ishibashi, Machiko;Takumi, Shigeo
WDREB2以前被分离为DREB2同源物，在非生物胁迫下（例如冷，干旱和高盐度）在小麦幼苗中表达，并在用外源性ABA治疗后。在本研究中，我们生成了表达WDREB2的转基因烟草植物，以阐明WDREB2在胁迫耐受性中的作用和WDREB2对COR/LEA基因的直接反式激活。 WDREB2表达显着改善了烟草植物中的冻结和渗透胁迫耐受性。在四个小麦cor/lea基因的5'上游区域中发现了几种推定的应力和ABA响应性顺式元素，WDHN13，WRAB17，WRAB18和WRAB19。转基因烟草植物中的冷，干旱和ABA治疗增强了在COR/LEA启动子序列控制下的GUSA报告基因的表达水平。此外，在不可能的条件下WDREB2表达明显提高了GUSA表达水平。这些结果清楚地表明，WDREB2充当转录因子，并积极调节WDHN13，WRAB17，WRAB18和WRAB19在小麦中多种非生物胁迫耐受性的发展。
Wdreb2, previously isolated as a DREB2 homolog, is expressed in wheat seedlings under abiotic stresses, such as cold, drought, and high salinity, and following treatment with exogenous ABA. In the present study, we generated transgenic tobacco plants expressing Wdreb2 to clarify roles of Wdreb2 in stress tolerance and the direct trans-activation of Cor/Lea genes by WDREB2. Wdreb2 expression significantly improved freezing and osmotic stress tolerance in tobacco plants. Several putative stress- and ABA-responsive cis-elements were found in the 5' upstream regions of four wheat Cor/Lea genes, Wdhn13, Wrab17, Wrab18, and Wrab19. The expression level of a gusA reporter gene under control of Cor/Lea promoter sequences was enhanced by cold, drought and ABA treatment in transgenic tobacco plants. Moreover, the gusA expression level was markedly enhanced by Wdreb2 expression under nonstressful conditions. These results clearly indicate that WDREB2 acts as a transcription factor and positively regulates Wdhn13, Wrab17, Wrab18, and Wrab19 in the development of multiple abiotic stress tolerance in wheat.