To explore heat response mechanisms of mircoRNAs (miRNAs) in rice post-meiosis panicle, microarray analysis was performed on RNA isolated from rice post-meiosis panicles which were treated at 40°C for 0 min, 10 min, 20 min, 60 min, and 2 h. By integrating paired differentially expressed (DE) miRNAs and mRNA expression profiles, we found that the expression levels of 29 DE-miRNA families were negatively correlated to their 178 DE-target genes. Further analysis showed that the majority of miRNAs in 29 DE-miRNA families resisted the heat stress by downregulating their target genes and a time lag existed between expression of miRNAs and their target genes. Then, GO-Slim classification and functional identification of these 178 target genes showed that (1) miRNAs were mainly involved in a series of basic biological processes even under heat conditions; (2) some miRNAs might play important roles in the heat resistance (such as osa-miR164, osa-miR166, osa-miR169, osa-miR319, osa-miR390, osa-miR395, and osa-miR399); (3) osa-miR172 might play important roles in protecting the rice panicle under the heat stress, but osa-miR437, osa-miR418, osa-miR164, miR156, and miR529 might negatively affect rice fertility and panicle flower; and (4) osa-miR414 might inhibit the flowering gene expression by downregulation of LOC_Os 05g51830 to delay the heading of rice. Finally, a heat-induced miRNA-PPI (protein-protein interaction) network was constructed, and three miRNA coregulatory modules were discovered.

中文翻译：

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基于水稻减数分裂后穗序的微阵列数据研究microRNA的热响应机制

为了探索水稻减数分裂后穗中mircoRNA（miRNA）的热响应机制，对从水稻减数分裂后穗中分离的RNA进行了微阵列分析，将其在40°C分别处理0分钟，10分钟，20分钟，60分钟，和2小时 通过整合成对的差异表达（DE）miRNA和mRNA表达谱，我们发现29个DE-miRNA家族的表达水平与其178个DE-靶基因负相关。进一步的分析表明，29个DE-miRNA家族中的大多数miRNA通过下调其靶基因来抵抗热应激，并且miRNA的表达与其靶基因之间存在时间滞后。然后，对这178个靶基因进行GO-Slim分类和功能鉴定表明：（1）miRNA即使在高温条件下也主要参与一系列基本生物学过程；（2）一些miRNA可能在耐热性中起重要作用（例如osa-miR164，osa-miR166，osa-miR169，osa-miR319，osa-miR390，osa-miR395和osa-miR399）; （3）osa-miR172可能在热胁迫下在保护水稻穗上起重要作用，但是osa-miR437，osa-miR418，osa-miR164，miR156和miR529可能会对水稻的育性和穗花产生负面影响；（4）osa-miR414可能通过下调LOC_Os 05g51830来抑制水稻开花，从而抑制开花基因的表达。最后，构建了一个热诱导的miRNA-PPI（蛋白质-蛋白质相互作用）网络，并发现了三个miRNA调控模块。（3）osa-miR172可能在热胁迫下在保护水稻穗上起重要作用，但是osa-miR437，osa-miR418，osa-miR164，miR156和miR529可能会对水稻的育性和穗花产生负面影响；（4）osa-miR414可能通过下调LOC_Os 05g51830来抑制水稻开花，从而抑制开花基因的表达。最后，构建了一个热诱导的miRNA-PPI（蛋白质-蛋白质相互作用）网络，并发现了三个miRNA调控模块。（3）osa-miR172可能在热胁迫下在保护水稻穗上起重要作用，但是osa-miR437，osa-miR418，osa-miR164，miR156和miR529可能会对水稻的育性和穗花产生负面影响；（4）osa-miR414可能通过下调LOC_Os 05g51830来抑制水稻开花，从而抑制开花基因的表达。最后，构建了一个热诱导的miRNA-PPI（蛋白质-蛋白质相互作用）网络，并发现了三个miRNA调控模块。