Variation in NRT1.1B contributes to nitrate-use divergence between rice subspecies
Variation in NRT1.1B contributes to nitrate-use divergence between rice subspecies
复制标题
DOI：
10.1038/ng.3337
复制
发表时间：
2015-07-01
期刊：
影响因子：
30.8
通讯作者：
Chu, Chengcai
中科院分区：
文献类型：
--
作者：
Hu, Bin;Wang, Wei;Chu, Chengcai
亚洲栽培稻（Oryza sativa L.）包括两个主要亚种，籼稻和粳稻。籼稻比粳稻具有更高的硝酸盐吸收活性，但这种活性背后的分子机制仍然难以捉摸。在这里，我们表明，硝酸盐转运蛋白基因，NRT1.1B（OsNPF6.5）的变化，可能有助于这种分歧在硝酸盐的使用。系统发育分析表明，NRT1.1B基因在籼、粳之间存在差异。NRT 1.1B-籼稻变异与硝酸盐吸收和根-冠运输的增强以及硝酸盐响应基因的表达上调有关。NRT 1.1B-籼稻的选择标记表明，在水稻驯化过程中发生了硝酸盐利用分化。值得注意的是，近等基因和转基因株系的田间试验证实，与没有该等位基因的品种相比，携带NRT 1. 1B-indica等位基因的粳稻品种显著提高了籽粒产量和氮利用效率（NUE）。研究结果表明，NRT1.1B基因的变异在很大程度上解释了籼粳间硝态氮利用的差异，NRT1.1Bindica基因有可能提高粳稻的氮利用效率。
Asian cultivated rice (Oryza sativa L.) consists of two main subspecies, indica and japonica. Indica has higher nitrate-absorption activity than japonica, but the molecular mechanisms underlying that activity remain elusive. Here we show that variation in a nitrate-transporter gene, NRT1.1B (OsNPF6.5), may contribute to this divergence in nitrate use. Phylogenetic analysis revealed that NRT1.1B diverges between indica and japonica. NRT1.1B-indica variation was associated with enhanced nitrate uptake and root-to-shoot transport and upregulated expression of nitrate-responsive genes. The selection signature of NRT1.1B-indica suggests that nitrate-use divergence occurred during rice domestication. Notably, field tests with near-isogenic and transgenic lines confirmed that the japonica variety carrying the NRT1.1B-indica allele had significantly improved grain yield and nitrogen-use efficiency (NUE) compared to the variety without that allele. Our results show that variation in NRT1.1B largely explains nitrate-use divergence between indica and japonica and that NRT1.1Bindica can potentially improve the NUE of japonica.