水稻AP2/ERF转录因子家族及其相应miRNAs在叶片衰老中的表达

Expression of rice AP2/ERF transcription factor family and corresponding miRNAs during leaf senescence

【目的】探究水稻AP2/ERF转录因子在叶片衰老中的功能及其受miRNA和组蛋白修饰调控的转录机制。【方法】在全基因组水平对水稻(Oryza sativa)AP2/ERF家族成员及其上游靶向的miRNAs进行鉴定和生物信息学分析。对miRNA及其靶基因在水稻叶片衰老过程中的表达谱进行分析。通过RT⁃qPCR检测该家族成员及miRNAs在水稻叶片衰老过程中的互作关系。【结果】在水稻中共有155个AP2/ERF基因,所有成员启动子都含有光响应元件,大多数基因都具有茉莉酸(jasmonic acid,JA)、脱落酸(abscisic acid,ABA)和厌氧诱导顺式作用元件。预测到45个miRNAs靶向调控水稻AP2/ERF家族的58个成员。鉴定出一系列在水稻叶片衰老过程中呈显著负相关的miRNA-靶基因对,暗示这些miRNAs可能通过抑制AP2/ERF基因的表达,参与水稻叶片衰老过程的调控。同时,发现4个AP2/ERF基因的表达量及其组蛋白H3K9ac富集水平随水稻叶片的衰老持续上升,说明这些基因表达同时受到H3K9ac修饰调控。【结论】在水稻叶片衰老过程中AP2/ERF基因的转录受其相应靶向的miRNAs和组蛋白H3K9ac修饰的影响。

【Objective】The study aimed to provide reference for investigating the role of AP2/ERF transcription factors during leaf senescence and their transcriptional regulation mechanisms by miRNA and histone modification.【Method】The members of AP2/ERF transcription factor family and their corresponding upstream⁃targeted miRNAs in rice(Oryza sativa)were identified and analyzed at the whole⁃genome level.Subsequently,the expression profiles of miRNAs and their target genes during leaf senescence were ana⁃lyzed,and their interactions were detected using RT⁃qPCR.【Result】A total of 155 AP2/ERF genes were identified in rice,whose promoters all contained light⁃responsive elements,and mostly had jasmonic acid(JA),abscisic acid(ABA)and anaerobic induction cis⁃elements.Up to 45 miRNAs,which targeted 58 members of the rice AP2/ERF family,were predicted.Significantly negative cor⁃relations were identified between certain miRNA⁃target gene pairs during rice leaf senescence,implying that these miRNAs may par⁃ticipate in leaf senescence by inhibiting the expression of AP2/ERF genes.Furthermore,the expression levels of 4 AP2/ERF genes and their H3K9ac enrichment levels were found to increase continuously during leaf senescence,indicating that the expression of these genes were simultaneously regulated by H3K9ac modification.【Conclusion】The results above revealed that the transcription of AP2/ERF genes was influenced by their corresponding miRNAs and histone H3K9ac modification during rice leaf senescence.