Early Drought-Responsive Genes Are Variable and Relevant to Drought Tolerance
Early Drought-Responsive Genes Are Variable and Relevant to Drought Tolerance
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DOI：
10.1534/g3.120.401199
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发表时间：
2020-05-01
影响因子：
2.6
通讯作者：
Liu, Sanzhen
中科院分区：
文献类型：
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作者：
He, Cheng;Du, Yicong;Liu, Sanzhen
干旱胁迫是世界范围内重要的作物产量限制因素。植物对干旱胁迫的生理反应是由基因表达的变化驱动的。虽然玉米中已鉴定出干旱响应基因（DRG），但渐进性缺水期间基因表达的调控模式仍有待阐明。在这项研究中，我们从玉米自交系 B73 在水分充足和干旱条件下生成了时间序列转录组数据。两种条件之间的比较确定了 8,626 个 DRG 以及 DRG 发生的阶段（干旱早期、中期和晚期）。不同功能组的基因在这三个阶段受到调控。具体而言，早期和中期的 DRG 在不同的玉米品系中表现出更高的拷贝数变异，并且与晚期的 DRG 相比，它们表现出与耐旱性更强的相关性。此外，同一样本中的小RNA (sRNA) 和DRG 之间的表达相关性鉴定出201 个负相关的sRNA/DRG 对，其中包括与耐旱性高度相关的基因，例如两个谷氨酰胺合成酶基因gln2 和gln6。对渐进性干旱胁迫的动态基因响应的特征表明早期和中期 DRG 的重要适应作用，以及 sRNA 在干旱胁迫基因表达调控中发挥的作用。
Drought stress is an important crop yield limiting factor worldwide. Plant physiological responses to drought stress are driven by changes in gene expression. While drought-responsive genes (DRGs) have been identified in maize, regulation patterns of gene expression during progressive water deficits remain to be elucidated. In this study, we generated time-series transcriptomic data from the maize inbred line B73 under well-watered and drought conditions. Comparisons between the two conditions identified 8,626 DRGs and the stages (early, middle, and late drought) at which DRGs occurred. Different functional groups of genes were regulated at the three stages. Specifically, early and middle DRGs display higher copy number variation among diverse Zea mays lines, and they exhibited stronger associations with drought tolerance as compared to late DRGs. In addition, correlation of expression between small RNAs (sRNAs) and DRGs from the same samples identified 201 negatively sRNA/DRG correlated pairs, including genes showing high levels of association with drought tolerance, such as two glutamine synthetase genes, gln2 and gln6. The characterization of dynamic gene responses to progressive drought stresses indicates important adaptive roles of early and middle DRGs, as well as roles played by sRNAs in gene expression regulation upon drought stress.