miR156介导SPLs参与调控拟南芥种子成熟过程

miR156-mediated SPLs Controls the Regulation of Arabidopsis Seed Maturation

【目的】MicroRNA156s(miR156s)是一类非常保守的小RNA家族,探究其能否参与植物种子成熟的复杂基因表达调控网络,对提高种子质量和产量等性状具有重要意义。【方法】基于前人建立的报告基因筛选体系,分别对突变体MIM156-gus及SPLs-ox进行GUS活性分析,利用qRT-PCR技术鉴定miR156家族不同成员的组织表达特异性及突变体材料中种子成熟关键调控因子的表达情况。【结果】GUS染色后,以gus23为背景材料的MIM156及靶标基因SPL2、SPL10和SPL11的过表达突变体均在播种后14 d的幼苗中展现出了GUS表型。miR156家族中,miR156a、d、e和j在果荚中的表达量最高,至少是14 d幼苗的20倍,且MIM156下调表达突变体中LEC1、ABI3和FUS3的表达水平均有不同程度升高。【结论】miR156的下调表达和SPLs的过表达诱导SSPs基因的异位表达,且MIM156促进LEC1、ABI3和FUS3基因的表达,说明miR156/SPLs作为调控因子参与植物种子成熟过程。

【Objective】MicroRNA156s(miR156s)is a kind of very conservative small RNA family.The study on its participation in the regulatory network of gene expression during seed maturation in plants will play a key role in the improvement of seed qualities and yields.【Methods】Based on the reporter gene screening system established by predecessors,the GUS activities of mutants MIM156-gus and SPLs-ox were analyzed.The tissue expression characteristics of different members in miR156 family and expression of key regulatory factors during mutant seed maturation process were identified by qRT-PCR technology.【Results】After GUS staining,the four mutants showed GUS phenotype in 14-day-old seedlings,which were MIM156 and its target genes SPL2,SPL10 and SPL11 with gus23 as background material.In the miR156 family,the expression level of miR156a,d,e and j in silique was at least 20 times that of in 14-day-old seedlings.The expression levels of LEC1,ABI3 and FUS3 in the MIM156 down-regulated mutants were significantly increased to different degrees.【Conclusion】The down-regulation of miR156 and the over-expression of SPLs induced the ectopic expression of SSPs genes.Moreover,MIM156 promoted the expression of LEC1,ABI3 and FUS3 genes.These indicated that miR156/SPLs,as a regulatory factor,was involved in the process of plant seed maturation.