miRNA在沙田柚配子体自交不亲和反应中的差异表达与功能分析

Differential Expression and Functional Analysis of miRNA in Self-Incompatibility Reaction of Gametophytes of Citrus Citrus grandis var. Shatinyu Hort

以沙田柚自交1~3 d以及异交1~3 d花柱为实验材料,构建小RNA测序文库。利用HiSeq深度测序对Small RNA进行测序,然后对差异表达miRNA进行分类注释和靶基因预测,并对靶基因进行GO功能注释以及KEGG pathway注释。结果表明自交1~3 d花柱中已知miRNA的个数分别为178、179和186个,而新miRNA分别为640、739和801个。异交1~3 d花柱中的已知miRNA的个数分别为232、122和219个,新miRNA分别为1184、476和836个。在YJ1/ZJ1、YJ2/ZJ2、YJ3/ZJ3的比对中共获得了16个差异表达的已知miRNA以及23个差异表达的新miRNA。差异表达miRNA靶基因的GO功能显著性富集分析结果表明,这些miRNA靶基因的功能涉及到RNA降解、转录因子、植物激素、植物与病原菌相互作用、结合功能、激酶等代谢过程。通过本研究,挖掘出了一些与沙田柚自交不亲和相关的miRNA,可为今后阐明沙田柚配子体自交不亲和的分子机理提供依据。

This study aimed to understand the self-incompatibility mechanism in Citrus grandis var. Shatinyu. The one day, two days and three days styles of Shatinyu after self-pollination and cross-pollination were used to construct small RNA libraries and the all Small RNA were sequenced by high-throughput sequencing technique. Then, the differentially expressed miRNAs were classified and predicted, and the target genes were annotated and the KEGG pathway was used to investigate the effect of miRNA on the self-incompatibility of Citrus grandis var. Shatinyu. The results showed that there were 178, 179 and 186 known miRNA and 640, 739 and 801 novel miRNA in the 1~3 d self-pollination style, respectively. There were 232, 122 and 219 known miRNA and 1184, 476 and 836 novel miRNA in the 1~3 d cross-pollination style, respectively. Moreover, statistics of differentially expressed miRNA showed that there were 16 differentially expressed known miRNA and 23 differentially expressed novel miRNA coexisted in ZJ1/YJ1, ZJ2/YJ2 and ZJ3/YJ3. Gene Ontology enrichment analysis showed that the function of differentially expressed miRNA target gene was mainly involved in responsing to RNA degradation, transcription factors, plant hormones, plant-pathogen interaction, binding function, kinase and other metabolic processes. In sum, through this study, some miRNAs associated with self-incompatibility in Shatianyu were discovered. These results will provide a theoretical reference for further exploration of self-incompatibility molecular mechanism in Citrus grandis var. Shatinyu.