GhDREB1 enhances abiotic stress tolerance, delays GA-mediated development and represses cytokinin signalling in transgenic Arabidopsis
GhDREB1 enhances abiotic stress tolerance, delays GA-mediated development and represses cytokinin signalling in transgenic Arabidopsis
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DOI：
10.1111/j.1365-3040.2009.01995.x
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发表时间：
2009-08-01
影响因子：
7.3
通讯作者：
Zheng, Cheng-Chao
中科院分区：
文献类型：
--
作者：
Huang, Jin-Guang;Yang, Mei;Zheng, Cheng-Chao
植物对低温的耐受能力差异很大。CBF/DREB 1冷反应途径在许多植物中被发现，并在植物的低温耐受性中起着关键作用。在这里，我们表明，GhDREB 1是一个功能同源物，提高了转基因拟南芥的冷冻，盐和渗透胁迫的耐受性。GhDREB 1在拟南芥中的组成型表达导致了矮化和延迟开花表型，这可以通过外源GA的应用来挽救（3）。内源生物活性GA含量显着低于GhDREB 1过表达拟南芥比野生型植物。RT-PCR分析表明，转基因植株中GA合酶基因的转录水平高于野生型植株，而GA失活基因则较低。GhDREB 1对不同调控途径中的开花相关基因也有影响，这可能是导致延迟开花的原因之一。此外，GhDREB 1过表达的拟南芥表现出细胞分裂素（CK）的敏感性降低，这是与B型和A型ARR，在CK信号通路的两个关键组成部分的表达抑制。
Plants vary significantly in their ability to tolerate low temperatures. The CBF/DREB1 cold response pathway has been identified in many plant species and plays a pivotal role in low temperature tolerance. Here, we show that GhDREB1 is a functional homologue and elevates the freezing, salt and osmotic stress tolerance of transgenic Arabidopsis. The constitutive expression of GhDREB1 in Arabidopsis caused dwarfism and late flowering phenotypes, which could be rescued by exogenous application of GA(3). Endogenous bioactive GA contents were significantly lower in GhDREB1 overexpressing Arabidopsis than in wild-type plants. RT-PCR analyses revealed that the transcript levels of the GA synthase genes were higher in transgenics than in wild-type plants, whereas the GA deactivating genes were lower. Flowering related genes in different regulatory pathways were also affected by GhDREB1, which may account for the flowering delay phenotype. Moreover, the GhDREB1 overexpressing Arabidopsis exhibited decreased sensitivity to cytokinin (CK) which is associated with repression of expression of type-B and type-A ARRs, two key components in the CK-signalling pathway.