Identification of OsbZIP72 as a positive regulator of ABA response and drought tolerance in rice
Identification of OsbZIP72 as a positive regulator of ABA response and drought tolerance in rice
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DOI：
10.1007/s00425-008-0857-3
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发表时间：
2009-02-01
期刊：
影响因子：
4.3
通讯作者：
Han, Bin
中科院分区：
文献类型：
--
作者：
Lu, Guojun;Gao, Chenxi;Han, Bin
脱落酸（阿坝）是植物抗非生物胁迫的重要激素。一组bZIP转录因子在拟南芥阿坝信号通路中起重要作用。然而，很少有人知道他们的直向同源物在水稻中的功能，在那里他们可能拥有开发抗旱粮食作物的巨大潜力。在本研究中，我们的系统发育分析表明，这组bZIPs在拟南芥和水稻之间是进化上保守的，这意味着它们可能具有相似的功能。我们证明了与定量RT-PCR，这些OsbZIPs的表达显着诱导阿坝，ACC和非生物胁迫。OsbZIP 72是这一组中的一员，利用酵母杂交系统证明它是水稻ABRE结合因子。我们发现它可以与ABRE结合并反式激活酵母中下游的报告基因，并且反式激活依赖于它的N-末端区域。过量表达OsbZIP 72的转基因水稻表现出对阿坝的敏感性，阿坝反应基因如LEAs的表达水平升高，耐旱能力增强。这些结果表明OsbZIP 72通过阿坝信号通路在抗旱性中发挥积极作用，并且在抗旱性工程水稻中具有潜在的用途。
Abscisic Acid (ABA) is an important phytohormone involved in abiotic stress resistance in plants. A group of bZIP transcription factors play important roles in the ABA signaling pathway in Arabidopsis. However, little is known about the function of their orthologs in rice, where they may hold a great potential for developing drought resistant food crops. In this study, our phylogenetic analysis showed that this group of bZIPs was evolutionarily conserved between Arabidopsis and rice, which implies that they may share similar functions. We demonstrated with quantitative RT-PCR that the expressions of most of these OsbZIPs were significantly induced by ABA, ACC, and abiotic stresses. OsbZIP72, a member of this group, was proved to be an ABRE binding factor in rice using the yeast hybrid systems. We showed that it could bind to ABRE and transactivate the downstream reporter genes in yeast, and the transactivity was depending on its N-terminal region. Transgenic rice overexpressing OsbZIP72 showed a hypersensitivity to ABA, elevated levels of expression of ABA response gene such as LEAs, and an enhanced ability of drought tolerance. These results suggest that OsbZIP72 plays a positive role in drought resistance through ABA signaling, and is potential useful for engineering drought tolerant rice.