• MicroRNAs (miRNAs) are an important class of non‐coding small RNAs that regulate the expression of target genes through mRNA cleavage or translational inhibition. Previous studies have revealed their roles in regulating seed dormancy and germination in model plants such as Arabidopsis thaliana, rice (Oryza sativa) and maize (Zea mays). However, the miRNA response to exogenous gibberellic acid (GA) and abscisic acid (ABA) during seed germination in maize has yet to be explored.
• In this study, small RNA libraries were generated and sequenced from maize embryos treated with GA, ABA or double‐distilled water as control.
• A total of 247 miRNAs (104 known and 143 novel) were identified, of which 45 known and 53 novel miRNAs were differentially expressed in embryos in the different treatment groups. In total, 74 (37 up‐regulated and 37 down‐regulated) and 55 (23 up‐regulated and 32 down‐regulated) miRNAs were expressed in response to GA and to ABA, respectively, and a total of 18 known and 38 novel miRNAs displayed differential expression between the GA‐ and ABA‐treated groups. Using bioinformatics tools, we predicted the target genes of the differentially expressed miRNAs. Using GO enrichment and KEGG pathway analysis of these targets, we showed that miRNAs differentially expressed in our samples affect genes encoding proteins involved in the peroxisome, ribosome and plant hormonal signalling pathways.
• Our results indicate that miRNA‐mediated gene expression influences the GA and ABA signalling pathways during seed germination.

中文翻译：

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种子萌发过程中，玉米胚中响应ABA和GA的microRNA的全基因组鉴定和表征。

• 微小RNA（miRNA）是一类重要的非编码小RNA，可通过mRNA切割或翻译抑制来调节靶基因的表达。先前的研究揭示了它们在调节拟南芥，水稻（水稻（Oryza sativa）和玉米（Zea mays））等模型植物的种子休眠和萌发中的作用。然而，尚未探明miRNA对玉米种子萌发过程中外源赤霉素（GA）和脱落酸（ABA）的反应。
• 在这项研究中，从用GA，ABA或双蒸馏水作为对照处理的玉米胚中生成了小RNA库并对其进行了测序。
• 总共鉴定出247个miRNA（104个已知的miRNA和143个新的miRNA），其中45个已知的miRNA和53个新的miRNA在不同治疗组的胚胎中差异表达。总共有74（37个上调和37个下调）和55个（23个上调和32个下调）miRNA分别响应GA和ABA表达，共有18种已知的和38种新颖的miRNA在GA和ABA处理组之间显示差异表达。使用生物信息学工具，我们预测了差异表达的miRNA的靶基因。使用这些靶标的GO富集和KEGG途径分析，我们显示了在样品中差异表达的miRNA会影响编码与过氧化物酶体，核糖体和植物激素信号通路相关的蛋白质的基因。
• 我们的结果表明，miRNA介导的基因表达影响种子萌发期间的GA和ABA信号传导途径。