microRNAs(简称miRNA)是一类内源的长约20~24碱基的RNA分子,它们通过mRNA降解和翻译抑制等方式,特异地对靶基因进行转录后调控。叶发育是叶原基细胞有序的分裂,生长和分化的过程。研究表明miRNA通过靶基因的抑制作用,影响其表达水平和空间分布,参与叶发育过程的基因调控。
拟南芥miR393由2个基因座MIR393a和MIR393b编码,其靶基因是生长素受体TIR1(TRANSPORTINHIBITOR RESPONSE PROTEIN 1)和三个F-box家族成员AFB1(AUXIN SIGNALING F BOX PROTEIN 1)、AFB2和AFB3。本研究开展了拟南芥叶发育中MIR393基因表达模式的研究,并通过对miR393功能突变的转基因植株叶表型的观察,以期阐明miR393在叶发育中的功能。获得的主要结果如下:
1.叶发育过程MIR393基因家族表达模式研究
对启动子报告株系pMIR393a:GUS和pMIR393b:GUS的幼苗进行GUS组织化学染色,结果表明两者表达位置基本相同,但MIR393b启动子活性高于MIR393a。MIR393a和b主要在子叶叶脉...
【英文摘要】
MicroRNAs (miRNAs) are endogenous 20~24 nucleotide RNAs which target complementary mRNA transcripts for cleavage or transcriptional repression. In leaf development, each cell in the primordium divides, grows and differentiates in a controlled way. Recent years, miRNAs have been found to be involved in the regulatory networks of leaf development. miRNA-mediated endogenous gene repression can specify the temporal-and spatial-expression pattern of their targets, and play crucial roles in leaf development.
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