Development of abiotic stress tolerance via bZIP-type transcription factor LIP19 in common wheat
Development of abiotic stress tolerance via bZIP-type transcription factor LIP19 in common wheat
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DOI：
10.1093/jxb/ern014
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发表时间：
2008-03-01
影响因子：
6.9
通讯作者：
Takumi, Shigeo
中科院分区：
文献类型：
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作者：
Kobayashi, Fuminori;Maeta, Eri;Takumi, Shigeo
谷物脂19基因编码bzip型转录因子被认为在冷驯化过程中对基因表达起调控作用。然而，没有直接证据表明lip19型bzip与应激耐受性或应激反应性Cor/Lea基因的激活有关。为了了解通过LIP19转录因子产生非生物胁迫抗性的分子基础，我们分离并鉴定了小麦LIP19的同源物Wlip19。Wlip19的表达在低温条件下被激活，耐冻品种的表达量高于冻敏品种。Wlip19对干旱和外源ABA处理也有响应。表达wlip19的转基因烟草对非生物胁迫的耐受性显著提高，尤其是对冰冻的耐受性。在小麦Cor/Lea基因Wdhn13、Wrab17、Wrab18和Wrab19启动子序列的调控下，Wlip19在小麦愈伤组织和烟草植株中的表达增强。这些结果表明，WLIP19作为Cor/Lea基因的转录调控因子参与了非生物胁迫抗性的发育。此外，WLIP19与小麦OBF1同源物TaOBF1（另一个bzip型转录因子）之间存在直接的蛋白-蛋白相互作用，表明这种相互作用在谷物中是保守的。
Cereal lip19 genes encoding bZIP-type transcription factors are assumed to play a regulatory role in gene expression during the cold acclimation process. However, no direct evidence shows an association of LIP19-type bZIPs with stress tolerance or activation of stress-responsive Cor/Lea genes. To understand the molecular basis of development of abiotic stress tolerance through the LIP19 transcription factor, a wheat lip19 homologue, Wlip19, was isolated and characterized. Wlip19 expression was activated by low temperature in seedlings and was higher in a freezing-tolerant cultivar than in a freezing-sensitive one. Wlip19 also responded to drought and exogenous ABA treatment. Wlip19-expressing transgenic tobacco showed a significant increase in abiotic stress tolerance, especially freezing tolerance. Expression of a GUS reporter gene under the control of promoter sequences of four wheat Cor/Lea genes, Wdhn13, Wrab17, Wrab18, and Wrab19, was enhanced by Wlip19 expression in wheat callus and tobacco plants. These results indicate that WLIP19 acts as a transcriptional regulator of Cor/Lea genes in the development of abiotic stress tolerance. Moreover, direct protein-protein interaction between WLIP19 and a wheat OBF1 homologue TaOBF1, another bZIP-type transcription factor, was observed, suggesting that this interaction is conserved in cereals.