Plant miRNAs play crucial roles in responses to drought and developmental processes. It is essential to understand the association of miRNAs with drought-tolerance (DT), as well as their impacts on growth, development, and reproduction (GDP). This will facilitate our utilization of rice miRNAs in breeding. In this study, we investigated the time course of miRNA responses to a long-term drought among six rice genotypes by high-throughput sequencing. In total, 354 conserved miRNAs were drought responsive, representing obvious genotype- and stage-dependent patterns. The drought-responsive miRNAs (DRMs) formed complex regulatory network via their coexpression and direct/indirect impacts on the rice transcriptome. Based on correlation analyses, 211 DRMs were predicted to be associated with DT and/or GDP. Noticeably, 14.2% DRMs were inversely correlated with DT and GDP. In addition, 9 pairs of mature miRNAs, each derived from the same pre-miRNAs, were predicted to have opposite roles in regulating DT and GDP. This suggests a potential yield penalty if an inappropriate miRNA/pre-miRNA is utilized. miRNAs have profound impacts on the rice transcriptome reflected by great number of correlated drought-responsive genes. By regulating these genes, a miRNA could activate diverse biological processes and metabolic pathways to adapt to drought and have an influence on its GDP. Based on the temporal pattern of miRNAs in response to drought, we have described the complex network between DRMs. Potential associations of DRMs with DT and/or GDP were disclosed. This knowledge provides valuable information for a better understanding in the roles of miRNAs play in rice DT and/or GDP, which can facilitate our utilization of miRNA in breeding.

中文翻译：

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保守 miRNA 对干旱的时间响应及其与水稻耐旱性和生产力的关系


植物 miRNA 在应对干旱和发育过程中发挥着至关重要的作用。了解 miRNA 与耐旱性 (DT) 的关联及其对生长、发育和繁殖 (GDP) 的影响至关重要。这将有助于我们在育种中利用水稻 miRNA。在这项研究中，我们通过高通量测序研究了 6 种水稻基因型中 miRNA 对长期干旱反应的时间过程。总共有 354 个保守的 miRNA 对干旱有反应，代表了明显的基因型和阶段依赖性模式。干旱响应 miRNA（DRM）通过共表达以及对水稻转录组的直接/间接影响形成了复杂的调控网络。根据相关性分析，预计 211 个 DRM 与 DT 和/或 GDP 相关。值得注意的是，14.2% 的 DRM 与 DT 和 GDP 呈负相关。此外，9 对成熟 miRNA（均源自相同的 pre-miRNA）预计在调节 DT 和 GDP 方面具有相反的作用。这表明如果使用不合适的 miRNA/pre-miRNA，可能会导致产量损失。大量相关的干旱响应基因反映了 miRNA 对水稻转录组的深远影响。通过调节这些基因，miRNA可以激活多种生物过程和代谢途径以适应干旱并对其GDP产生影响。基于 miRNA 响应干旱的时间模式，我们描述了 DRM 之间的复杂网络。披露了 DRM 与 DT 和/或 GDP 的潜在关联。这些知识为更好地理解 miRNA 在水稻 DT 和/或 GDP 中的作用提供了有价值的信息，这可以促进我们在育种中利用 miRNA。