Transcriptomic analysis of grain filling in rice inferior grains under moderate soil drying
Transcriptomic analysis of grain filling in rice inferior grains under moderate soil drying
复制标题
中度土壤干燥条件下水稻劣质籽粒灌浆的转录组分析
DOI：
10.1093/jxb/erz010
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发表时间：
2019-02-15
影响因子：
6.9
通讯作者：
Zhang, Jianhua
中科院分区：
文献类型：
--
作者：
Wang, Guan-Qun;Li, Hao-Xuan;Zhang, Jianhua
适度的土壤干燥在开花后阶段施加显着增加淀粉积累的水稻弱势粒，但这一过程是如何在基因表达水平上的调控仍不清楚。在这项研究中，我们在开花后阶段对土壤进行适度干燥（MD）处理，并使用RNA-seq分析跟踪弱势粒中可溶性糖向淀粉转化过程的动态。由MD诱导的阿坝水平升高与ABA 8 ox 2的下调一致，这表明该基因的较低表达可能是导致较高阿坝含量的原因，可能导致弱势粒更好的灌浆。此外，MD处理上调了编码蔗糖转化为淀粉的5个关键酶的基因，并增加了弱势粒中负责可溶性糖还原和淀粉积累的酶的活性。差异表达的转录因子包括NAC、加塔、WRKY和M型MADS，这些转录因子与其它蛋白质相互作用，介导弱势粒灌浆，作为对MD的响应。瞬时表达分析表明NAC通过与WAXY启动子结合激活WAXY表达，表明NAC在MD处理下弱势粒淀粉合成中起关键作用。我们的研究结果提供了新的见解的分子机制，调节水稻弱势粒灌浆适度土壤干燥。
Moderate soil drying imposed at the post-anthesis stage significantly increases starch accumulation in inferior grains of rice, but how this process is regulated at the level of gene expression remains unclear. In this study, we applied moderate drying (MD) treatments to the soil at the post-anthesis stage and followed the dynamics of the conversion process of soluble sugars to starch in inferior grains using RNA-seq analysis. An elevated level of ABA induced by MD was consistently associated with down-regulation of ABA8ox2, suggesting that lower expression of this gene may be responsible for the higher ABA content, potentially resulting in better filling in inferior grains. In addition, MD treatments up-regulated genes encoding five key enzymes involved sucrose-to-starch conversion and increased the activities of enzymes responsible for soluble-sugar reduction and starch accumulation in inferior grains. Differentially expressed transcription factors, including NAC, GATA, WRKY, and M-type MADS, were predicted to interact with other proteins in mediating filling of inferior grains as a response to MD. Transient expression analysis showed that NAC activated WAXY expression by binding to its promoter, indicating that NAC played a key role in starch synthesis of inferior grains under MD treatment. Our results provide new insights into the molecular mechanisms that regulate grain filling in inferior grains of rice under moderate soil drying.