高表达miR396小分子导致拟南芥花柱头弯曲

Overexpression of miR396 miRNAs Caused Flower Stigma Curved in Arabidopsis thaliana

MicroRNAs(miRNAs)是大小约21个碱基、内源、非编码的小分子RNA。以拟南芥(Arabidopsis thaliana)miR396小分子为研究对象,分别克隆到了miR396小分子的两个前体(MIR396a,MIR396b),得到了转基因植株。通过转基因植株的遗传学研究发现,高表达miR396小分子导致转基因拟南芥的花柱头弯曲。花柱头的弯曲影响了角果的正常发育。另外,Northern杂交结果表明转基因拟南芥花部位的miR396及其前体的表达量与对照相比显著增加。这些结果表明高表达miR396小分子可以导致拟南芥花柱头弯曲。

MicroRNAs （miRNAs） are -21 nucleotide （nt）, endogenous and encoding RNAs that play important regulatory roles in growth and development by targeting mRNAs for direct cleavage or translational repression in plants. To analyze the biological function of miR396, we placed two synthetic precursors, MIR396a or MIR396b, under the control of the enhanced Cauliflower mosaic virus （CaMV） 35S promoter in a plant transformation vector （pOCA30） and transformed the corrstructs into Arabiciopsis. Genetic analysis showed that flower stigmas of 35S ： MIR396 transgenic Arabidopsis were curve and siliques of miR396 transgenic plants were abnormal. In addition, Northern blot analysis showed that the miR396 miRNAs and levels of MIR396 precursor transcripts were significantly increased in transgenic miR396 plants compared with control. These results strongly supported that miR396 played an important role in plant flower development.