Arabidopsis Zinc Finger Proteins AtC3H49/AtTZF3 and AtC3H20/AtTZF2 are Involved in ABA and JA Responses
Arabidopsis Zinc Finger Proteins AtC3H49/AtTZF3 and AtC3H20/AtTZF2 are Involved in ABA and JA Responses
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DOI：
10.1093/pcp/pcs023
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发表时间：
2012-04-01
影响因子：
4.9
通讯作者：
Kim, Soo Young
中科院分区：
文献类型：
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作者：
Lee, Sun-ji;Jung, Hyun Ju;Kim, Soo Young
拟南芥基因组中有68个CCCH锌指蛋白基因。然而，它们中只有几个被功能化了。本文报道了两个拟南芥CCCH锌指蛋白AtC3H49/AtTZF3和AtC3H20/AtTZF2的功能。为了研究它们的功能，我们检测了它们的表达模式，并分析了它们的过表达和敲除(KO)/RNA干扰(RNAi)表型。AtC3H49/AtTZF3和AtC3H20/AtTZF2基因在不同的营养组织和花中均有表达，其编码蛋白定位于细胞质中。AtC3H49/AtTZF3或AtC3H20/AtTZF2的过表达使ABA敏感，蒸腾作用减弱，抗旱性增强。它们的过度表达也改变了植物的生长模式。转基因植株生长前期生长缓慢，后期生长速度加快，成熟植株大于野生型植株。此外，转基因植株具有延缓衰老和延长寿命的特点。随后的实验表明，茉莉酸(JA)诱导的衰老也被延缓。基因芯片和定量逆转录-聚合酶链式反应分析表明，在转基因株系中，与JA、ABA和生物/非生物胁迫反应相关的一些基因的表达发生了变化。AtC3H49/AtTZF3和AtC3H20/AtTZF2重组蛋白在体外具有核糖核酸酶活性，提示它们可能参与了mRNA的翻转过程。AtC3H49/AtTZF3和AtC3H20/AtTZF2的敲除/RNAi系表现出较弱的表型，可能是因为它们的功能冗余。
There are 68 CCCH zinc finger protein genes in the Arabidopsis genome. However, only a few of them have been characerized functionally. In this paper, we report the function of two Arabidopsis CCCH zinc finger proteins AtC3H49/AtTZF3 and AtC3H20/AtTZF2. To investigate their functions, we examined their expression patterns and analyzed their overexpression and knockout(KO)/RNA interference (RNAi) phenotypes. Both AtC3H49/AtTZF3 and AtC3H20/AtTZF2 genes were expressed in various vegetative tissues and in flowers, and their encoded proteins were localized in the cytoplasm. Overexpression of AtC3H49/AtTZF3 or AtC3H20/AtTZF2 conferred ABA hypersensitivity, reduced transpiration and enhanced drought tolerance. Their overexpression also altered the plant growth pattern. The transgenic plants grew slowly during the early stage of growth, but their growth rates were accelerated at later stages, and mature plants were larger than the wild-type plants. Moreover, the transgenic plants displayed delayed senescence and enhanced longevity. Subsequent experiments showed that jasmonic acid (JA)-induced senescence was also delayed. Microarray and quantitative reverse transcription-PCR analyses indicated that the expression of a number of genes involved in JA, ABA and biotic/abiotic stress responses was altered in the transgenic lines. Recombinant AtC3H49/AtTZF3 and AtC3H20/AtTZF2 proteins displayed RNase activity in vitro, suggesting that they may be involved in mRNA turnover process. The knockout/RNAi lines of AtC3H49/AtTZF3 and AtC3H20/AtTZF2 exhibited weak phenotypes, presumably because of their functional redundancy.