盐穗木miRNA417的克隆及对种子萌发和幼苗成活率的影响

Cloning of miR417 Gene from Halostachys caspica and Its Effects on the Rates of Seed Germination and Seedling Survival

MicroRNA(miRNA)是植物重要的基因表达调控因子,miR417的表达受盐胁迫的调节,高盐胁迫时,拟南芥miR417的表达能够抑制种子的萌发和幼苗成活。本研究通过分析miRbase数据库中已知植物miRNA417的序列,利用PCR技术成功克隆获得了盐生植物盐穗木的miR417(HcmiR417)的前体序列,将其构建至植物表达载体pCAMBIA1301上,通过花絮浸染法对拟南芥进行遗传转化。结果表明,在150 mmol·L-1NaCl的胁迫下,分别过表达HcmiR417和过表达拟南芥miRNA417(AtmiR417)的转基因拟南芥种子的萌发率和幼苗存活率均较野生型低,但两种转基因拟南芥株系之间没有差异。初步验证了盐生植物HcmiR417在种子萌发和幼苗成活率方面也具有负调控作用,盐生植物盐穗木和拟南芥植物miRNA在功能没有显示出差异。

MicroRNAs（miRNAs） are important gene regulating factor in plant.A series of researches show that expression of miR417 can be controlled by salt stress.In high salt conditions,miR417 of Arabidopsis has negatively regulating roles on the rate of the seed germination and seedling survival.According to the miRNA417 sequence analysis of known plants in miRbase database,the pre-miR417 has been successfully cloned from halophyte Halostachys caspica by the PCR technique in the present study.After the construction of plant expression vector pCAMBIA1301,the recombinant plasmid was transformed to Arabidopsis thaliana.The result indicated that the over-expression lines of HcmiR417 and miRNA417 had lower rates of seed germination and seedling survival than those of the wild type,but there was no significant difference between the two transformed lines.It primarily suggests that HcmiR417 plays a negative role in the seed germination and seedling survival,while the function of miRNA has no difference between Arabidopsis and H.caspica.