摘要： 为研究植物miR399家族成员构成、分子特征及其靶基因功能，利用生物信息学方法对植物miR399家族成员数量、系统进化、二级结构、启动子特征及靶基因功能进行分析。共获得244个成熟miR399成员，仅分布在被子植物中，不同物种中pre-miR399和miR399的数量分布差异较大；大多数pre-miR399仅剪切为单个成熟miR399，数量最多的pre-miR399长度为64 nt，93.85%的成熟miR399序列长度为21 nt；pre-miR399序列分析显示，3'端保守性高于5'端，且大部分成熟miR399序列来源于3'端，保守序列为UGCCAAAGGAGA*UUGCCC*G；进化分析显示，miR399序列一致性较高，但不同种属间聚类关系较复杂；植物pre-miR399主要分为3种类型：①产生1条成熟miR399，且位于pre-miR399的3'端；②产生2条成熟miR399，分别位于pre-miR399的3'端和5'端；③产生1条成熟miR399，且位于pre-miR399的5'端；pre-miR399启动子区含有大量激素和胁迫响应元件；水稻miR399家族靶基因本体分析显示，细胞组分分类中的细胞和细胞部分类别占比均为59.1%，分子功能分类中的催化活性和结合类型占比分别为40.9%和45.5%，miR399调控了多个磷响应和磷转运靶基因，这些基因主要参与了植物磷代谢、应激响应、基因表达调控等多项进程。研究表明，miR399在植物进化过程中高度保守，能够响应多种不同信号，其参与了植物的多种生命过程，尤其在植物磷饥饿胁迫和磷转运中发挥重要作用。

关键词: miR399, 进化, 靶基因, 磷胁迫

Abstract: MicroRNA plays a variety of important regulatory roles in cells. The miR399 family plays a role in plant response to phosphorus starvation stress. In order to further understand the composition, molecular characteristics and target gene function of plant miR399 family, the number, phylogeny, secondary structure, promoter characteristics and target genes of miR399 family were analyzed by bioinformatics methods. Results showed that a total of 244 mature miR399 members were obtained, distributing only in angiosperms. The distribution of pre-miR399 and mature miR399 in different species varied greatly. Most pre-miR399 was only cut into a single mature miR399. The pre-miR399 with the largest number was 64 nt, and 93.85% of mature miR399 was only 21 nt. Pre-miR399 sequence analysis showed that 3' end was more conservative than 5' end. Most of the mature miR399 sequence was derived from the 3' end of pre-miR399, and the conservative sequence was UGCCAAAGGAGA*UUGCCC*G. Evolutionary analysis showed that the miR399 sequence was more consistent, but the cluster relationship of different species was complex. pre-miR399 was mainly divided into three types:①Producing one mature miR399 from 3' end;②Producing two mature miR399 respectively from 3' and 5' end; ③Producing one mature miR399 from 5' end. The pre-miR399 promoter region contained a large number of hormones and stress response elements. Gene ontology analysis of the target genes in rice miR399 family showed that the proportion of the cell and the cell part classifications were 59.1%, while the proportion of the catalytic activity and the binding types were 40.9% and 45.5% respectively. The miR399 regulated multiple phosphorus response and phosphorus transport target genes. Those target genes are mainly involved in plant phosphorus metabolism, stress response, gene expression regulation and many other processes. Above results indicated that miR399 was highly conserved and participated many signal processes, and played a role in plant phosphorus starvation stress and phosphorus transport.

Key words: miR399, Evolution, Target genes, Phosphorus stress

中图分类号: 

• Q789