Barley transcription factor HvNLP2 mediates nitrate signaling and affects nitrogen use efficiency
Barley transcription factor HvNLP2 mediates nitrate signaling and affects nitrogen use efficiency
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大麦转录因子 HvNLP2 介导硝酸盐信号传导并影响氮利用效率
DOI：
10.1093/jxb/erab245
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发表时间：
2021-06-25
影响因子：
6.9
通讯作者：
Wang, Yong
中科院分区：
文献类型：
--
作者：
Gao, Yangyang;Quan, Shuxuan;Wang, Yong
植物已经进化出复杂的机制来适应环境中不断变化的氮水平。在拟南芥中，十多个硝酸盐信号传导调节基因已得到表征，包括在硝酸盐信号传导中发挥重要作用的结节起始样蛋白（AtNLP）基因。然而，小麦科作物中的 NLP 基因是否参与硝酸盐调节和氮利用效率 (NUE) 仍不清楚。在这里，我们从 TILLING（靶向基因组中的局部病变）群体中分离出大麦 (Hordeum vulgare L.) 突变体 hvnlp2-1，并构建了两个 RNAi 系 hvnlp2-2 和 hvnlp2-3，以研究 HvNLP2 的功能。在 hvnlp2 突变体中，硝酸盐处理后，硝酸盐响应基因的表达显着受到抑制，表明 HvNLP2 控制硝酸盐信号传导。 hvnlp2突变体中硝酸盐含量显着较高，这可能是由于硝酸盐还原酶活性和硝酸盐同化基因表达降低导致氮同化减少所致。当硝酸盐存在时，HvNLP2 定位于细胞核。进一步研究表明 HvNLP2 结合并激活硝酸盐响应顺式元件。此外，hvnlp2 表现出生物量、种子产量和 NUE 降低。因此，HvNLP2控制硝酸盐信号传导，在NUE中发挥重要作用。大麦转录因子HvNLP2介导硝酸盐信号传导和同化，与亚硝酸还原酶基因启动子的硝酸盐响应元件结合，影响植物生物量、产量和氮利用效率。
Plants have evolved complex mechanisms to adapt to the changing nitrogen levels in the environment. In Arabidopsis, more than a dozen nitrate signaling regulatory genes have been characterized, including the NODULE INCEPTION-LIKE PROTEIN (AtNLP) genes, which play essential roles in nitrate signaling. However, whether NLP genes in the Triticeae crops are involved in nitrate regulation and nitrogen use efficiency (NUE) remains unknown. Here, we isolated a barley (Hordeum vulgare L.) mutant, hvnlp2-1, from a TILLING (Targeting Local Lesions IN Genomes) population and constructed two RNAi lines, hvnlp2-2 and hvnlp2-3, to study the function of HvNLP2. The expression of the nitrate-responsive genes was substantially inhibited after nitrate treatment in the hvnlp2 mutants, indicating that HvNLP2 controls nitrate signaling. Nitrate content was significantly higher in the hvnlp2 mutants, which may result from the decreased assimilation of nitrogen caused by reduced nitrate reductase activity and expression of nitrate assimilatory genes. HvNLP2 is localized to the nucleus in the presence of nitrate. Further investigation showed that HvNLP2 binds to and activates the nitrate-responsive cis-elements. Moreover, hvnlp2 exhibited reduced biomass, seed yield, and NUE. Therefore, HvNLP2 controls nitrate signaling and plays an important role in NUE.Barley transcription factor HvNLP2 mediates nitrate signaling and assimilation, binds to the nitrate response element of the nitrite reductase gene promoter, and affects plant biomass, yield, and nitrogen use efficiency.