The Wheat GT Factor TaGT2L1D Negatively Regulates Drought Tolerance and Plant Development
The Wheat GT Factor TaGT2L1D Negatively Regulates Drought Tolerance and Plant Development
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DOI：
10.1038/srep27042
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发表时间：
2016-06
影响因子：
4.6
通讯作者：
Xin Zheng;Haipei Liu;Hongtao Ji;Youning Wang;B. Dong;Yunzhou Qiao;Mengyu Liu;Xia Li
中科院分区：
文献类型：
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作者：
Xin Zheng;Haipei Liu;Hongtao Ji;Youning Wang;B. Dong;Yunzhou Qiao;Mengyu Liu;Xia Li
GT因子是一类特异性调控植物生长发育和逆境胁迫反应的三螺旋转录因子。最近，几个GT因子已在不同的植物物种的特点，但是，很少有人知道GT因子在小麦中的作用。在这里，我们表明，TaGT 2L 1A，TaGT 2L 1B和TaGT 2L 1D是高度同源的六倍体小麦，并定位于小麦染色体2A，2B和2D，分别。这些TaGT 2L 1基因编码含有两个SANT结构域和一个中央螺旋的蛋白质。这三个同源物在小麦发育过程中普遍表达，并对渗透胁迫有反应。功能分析表明，TaGT 2L 1D作为一个转录抑制因子，它能够抑制AtSDD 1在拟南芥中的表达，直接结合到其启动子中的GT3盒，负调节耐旱性。TaGT 2L 1D过表达显著增加了gtl 1 -3植株的气孔数量，降低了其耐旱性。值得注意的是，TaGT 2L 1D的异位表达也影响花器官发育和整体植物生长。这些结果表明，TaGT 2L 1是AtGTL 1的直系同源物，并且它通过微调气孔密度在小麦抗旱性中起着进化保守的作用。我们的数据还突出了TaGT 2L 1在植物生长和发育中的作用。
GT factors are trihelix transcription factors that specifically regulate plant development and stress responses. Recently, several GT factors have been characterized in different plant species; however, little is known about the role of GT factors in wheat. Here, we show that TaGT2L1A, TaGT2L1B, and TaGT2L1D are highly homologous in hexaploid wheat, and are localized to wheat chromosomes 2A, 2B, and 2D, respectively. These TaGT2L1 genes encode proteins containing two SANT domains and one central helix. All three homologs were ubiquitously expressed during wheat development and were responsive to osmotic stress. Functional analyses demonstrated that TaGT2L1D acts as a transcriptional repressor; it was able to suppress the expression of AtSDD1 in Arabidopsis by binding directly to the GT3 box in its promoter that negatively regulates drought tolerance. TaGT2L1D overexpression markedly increased the number of stomata and reduced drought tolerance in gtl1-3 plants. Notably, ectopic expression of TaGT2L1D also affected floral organ development and overall plant growth. These results demonstrate that TaGT2L1 is an ortholog of AtGTL1, and that it plays an evolutionarily conserved role in drought resistance by fine tuning stomatal density in wheat. Our data also highlight the role of TaGT2L1 in plant growth and development.