苋菜试管苗ama-miR319b前体的克隆及其在苋菜试管苗发育过程中的表达分析

Cloning of miR319b precursor gene and expressing analysis during the in vitro plantlets development by qPCR in Amaranthus tricolor L.

试验以苋菜试管苗及该试管苗发育过程中各阶段培养物为材料,进行miR319b前体的克隆及其在苋菜试管苗发育过程中的qPCR分析.结果表明:采用RT-PCR法克隆到苋菜miR319b前体序列,长186bp.该前体与烟草、苜蓿等miR319b前体序列具有较高的同源性,并包含长21bp的miR319b的成熟序列;利用qPCR技术研究显示,该miRNA在苋菜试管苗发育过程中的表达具有特异性,在幼苗期时相对表达量最低,而在壮苗期和花芽期相对表达量迅速增加,且在花芽期时达到最高值;进入开花期,其相对表达量又呈下降趋势,但略高于壮苗期.说明ama-miR319b前体在苋菜幼苗期向壮苗期转变及花芽期向开花期转变阶段可能起重要作用,这为将来进一步研究其功能奠定了基础.

In vitro plantlets and the cultures during the in vitro plantlets development were used as the materials to clone miR319b precursor by RT-PCR, and its expression level during the in vitro plantlets development in Amaranthus tricolor L was conducted by qPCR. The results show that rniR319b precursor is 186 bp in length, including 21 bp mature sequence of miR319b. Meanwhile the miR319b precursor of Amaronthus tricolor L shows high sequence homology with that from Nicotiana tabacum and Medicago sativa. With qPCR,we can find that the relative expres- sion level of ama-miR 319b is the lowest at the young seedling stage, then up-regulated at the adult seedling stage and the flower-bud stage. It is highest at flower-bud stage, then is decreased. The relative expression level at flowering stage is slightly higher than that at adult seedling stage. Therefore, the miR319b precursor perhaps plays the important role in regulating the conversion from the young seedling stage to the adult seedling stage, as well as from the vegetative growth to the reproductive growth. This study is helpful for further study of ama-miR319b functions.