The Nitrate-Inducible NAC Transcription Factor TaNAC2-5A Controls Nitrate Response and Increases Wheat Yield
The Nitrate-Inducible NAC Transcription Factor TaNAC2-5A Controls Nitrate Response and Increases Wheat Yield
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硝酸盐诱导 NAC 转录因子 TaNAC2-5A 控制硝酸盐反应并提高小麦产量
DOI：
10.1104/pp.15.00568
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发表时间：
2015-11-01
期刊：
影响因子：
7.4
通讯作者：
Tong, Yiping
中科院分区：
文献类型：
--
作者：
He, Xue;Qu, Baoyuan;Tong, Yiping
硝酸盐是谷类作物氮素的主要来源；因此，了解谷类作物的硝酸盐信号对提高氮素利用效率的工程作物具有重要意义。虽然在拟南芥（Arabidopsis thaliana）中已经确定了几种硝酸盐传感和信号传导的调节因子，但在谷物中却缺乏相应的信息。在这里，我们从小麦（Triticum aestivum）中分离出一种硝酸盐诱导和谷物特异性的NAM、ATAF和CUC （NAC）转录因子TaNAC2-5A。染色质免疫沉淀实验表明，TaNAC2-5A可以直接结合硝酸盐转运蛋白和谷氨酰胺合成酶基因的启动子区域。TaNAC2-5A在小麦中的过表达促进了根系生长和硝酸盐流入速率，从而提高了根系获取氮的能力。此外，在田间试验中，我们发现过表达tanac2 - 5a的转基因小麦品系具有更高的产量和地上部分氮积累，籽粒中氮分配也更多。这些结果表明TaNAC2-5A参与了硝酸盐信号转导，并表明它是一种令人兴奋的基因资源，可用于培育更有效利用肥料的作物。
Nitrate is a major nitrogen resource for cereal crops; thus, understanding nitrate signaling in cereal crops is valuable for engineering crops with improved nitrogen use efficiency. Although several regulators have been identified in nitrate sensing and signaling in Arabidopsis (Arabidopsis thaliana), the equivalent information in cereals is missing. Here, we isolated a nitrateinducible and cereal-specific NAM, ATAF, and CUC (NAC) transcription factor, TaNAC2-5A, from wheat (Triticum aestivum). A chromatin immunoprecipitation assay showed that TaNAC2-5A could directly bind to the promoter regions of the genes encoding nitrate transporter and glutamine synthetase. Overexpression of TaNAC2-5A in wheat enhanced root growth and nitrate influx rate and, hence, increased the root's ability to acquire nitrogen. Furthermore, we found that TaNAC2-5A-overexpressing transgenic wheat lines had higher grain yield and higher nitrogen accumulation in aerial parts and allocated more nitrogen in grains in a field experiment. These results suggest that TaNAC2-5A is involved in nitrate signaling and show that it is an exciting gene resource for breeding crops with more efficient use of fertilizer.