EcbZIP60, a basic leucine zipper transcription factor from Eleusine coracana L. improves abiotic stress tolerance in tobacco by activating unfolded protein response pathway
EcbZIP60, a basic leucine zipper transcription factor from Eleusine coracana L. improves abiotic stress tolerance in tobacco by activating unfolded protein response pathway
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DOI：
10.1007/s11032-015-0374-6
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发表时间：
2015-09-01
影响因子：
3.1
通讯作者：
Udayakumar, M.
中科院分区：
文献类型：
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作者：
Babitha, K. C.;Ramu, S. V.;Udayakumar, M.
碱性亮氨酸拉链 (bZIP) 是最大的转录因子家族之一，已被证明在植物生长发育中发挥着多种作用。已知这些蛋白质在胁迫条件下调节植物中的许多细胞反应。在这项研究中，从牛筋草 (Eleusine coracana) 中克隆了属于 bZIP 家族的应激反应转录因子，并在烟草中进行了功能验证。在干旱、渗透压、盐和甲基紫精诱导的胁迫下，小米中 EcbZIP60 的表达高度上调。烟草中 EcbZIP60 的组成型表达导致正常生长条件下植物生长减少。然而，转基因植物表现出对干旱胁迫的更好的耐受性，具有更高的气孔导度和光合作用，从而改善了生长。转基因植物还表现出对盐度和甲基紫精诱导的氧化应激以及内质网应激诱导剂二硫苏糖醇和衣霉素的耐受性增强。转基因植物在正常和胁迫条件下都表现出未折叠蛋白响应途径基因（例如 BiP1、CRT1 和 PDIL）的显着上调，尽管脱水蛋白组基因没有表现出任何上调。结果表明，表达 EcbZIP60 的转基因烟草对多种胁迫的耐受性提高可能是通过未折叠的蛋白质响应信号通路实现的。
The basic leucine zippers (bZIPs) are one of the largest families of transcription factors that have been demonstrated to play diverse roles in plant growth development. These proteins are known to regulate many cellular responses in plants under stress conditions. In this study, a stress-responsive transcription factor belonging to bZIP family was cloned from finger millet (Eleusine coracana) and functionally validated in tobacco. The expression of EcbZIP60 was highly upregulated under drought, osmotic, salt and methyl viologen-induced stress in finger millet. Constitutive expression of EcbZIP60 in tobacco resulted in reduced growth of plants under normal growth conditions. However, the transgenic plants showed improved tolerance to drought stress with higher stomatal conductance and photosynthesis, resulting in improved growth. The transgenic plants also showed increased tolerance to salinity and methyl viologen-induced oxidative stress and to endoplasmic reticulum stress inducers dithiothreitol and tunicamycin. The transgenic plants showed significant upregulation of unfolded protein-responsive pathway genes such as BiP1, CRT1 and PDIL both under normal and stress conditions, although dehydrin group of genes did not show any upregulation. The results demonstrate that improved tolerance of EcbZIP60-expressing transgenic tobacco to diverse stresses could be through unfolded protein-responsive signalling pathway.