Small RNAs (sRNAs) are short noncoding RNAs that play roles in many biological processes, including drought responses in plants. However, how the expression of sRNAs dynamically changes with the gradual imposition of drought stress in plants is largely unknown. We generated time‐series sRNA sequence data from maize (Zea mays L.) seedlings under drought stress (DS) and under well‐watered (WW) conditions at the same time points. Analyses of length, functional annotation, and abundance of 736,372 nonredundant sRNAs from both DS and WW data, as well as genome copy numbers at the corresponding genomic regions, revealed distinct patterns of abundance and genome organization for different sRNA classes. The analysis identified 6646 sRNAs whose regulation was altered in response to drought stress. Among drought‐responsive sRNAs, 1325 showed transient downregulation by the seventh day, coinciding with visible symptoms of drought stress. The profiles revealed drought‐responsive microRNAs, as well as other sRNAs that originated from ribosomal RNAs (rRNAs), splicing small nuclear RNAs, and small nucleolar RNAs (snoRNA). Expression profiles of their sRNA derivers indicated that snoRNAs might play a regulatory role through regulating the stability of rRNAs and splicing small nuclear RNAs under drought condition.

中文翻译：

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干旱下的时间小分子RNA表达分析揭示了小核仁RNA在玉米干旱反应中的潜在调控作用。

小RNA（sRNA）是短的非编码RNA，在许多生物过程中起作用，包括植物的干旱反应。然而，很大程度上未知植物中sRNA的表达如何随着干旱胁迫的逐渐施加而动态变化。我们从玉米（Zea mays）中生成了时间序列sRNA序列数据L.）幼苗同时处于干旱胁迫（DS）和水分充足（WW）的条件下。从DS和WW数据分析了736,372个非冗余sRNA的长度，功能注释和丰度，以及相应基因组区域的基因组拷贝数，揭示了不同sRNA类型的丰度和基因组组织的不同模式。分析确定了6646个sRNA，其调节响应干旱胁迫而改变。在对干旱有反应的sRNA中，第1325天显示出第七天的瞬时下调，这与干旱胁迫的可见症状相吻合。这些图谱揭示了干旱响应性microRNA，以及其他源自核糖体RNA（rRNA），剪接小核RNA和小核仁RNA（snoRNA）的sRNA。