陆地棉无绒突变体miRNA的鉴定及其靶标基因分析

Identification of miRNAs and Target Gene Analysis in Cotton Fiber

【目的】棉花纤维突起影响纤维的产量和品质,挖掘纤维起始相关的小RNA及其靶基因对于研究纤维起始机制至关重要。【方法】本研究以新乡小吉的野生型(Wild type,WT)及其无绒有絮突变体(Fuzzless mutant,FLM)开花当天的胚珠为材料,构建6个小RNA文库并进行高通量测序,以陆地棉(Gossypium hirsutum L.)基因组序列作为参考。【结果】共发现459个mi RNA,包括301个保守的mi RNA和158个新mi RNA。共得到13个差异表达的mi RNA,预测并分析了它们的靶基因。通过对靶基因的生物信息学分析结果显示,预测的这些靶基因侧重于编码HD-ZIP (Homeodomain-leucine zipper)、GRAS (Gibberellic acid insensitive,Repressor of GAI,Scarecrow)、AP2 (APETALA2)家族的转录因子,功能集中在转录和转录后调控阶段。对靶基因进行Gene Ontology (GO)注释发现,它们参与细胞分化、花药发育、花器官发育等生物学过程。随机选出4个mi RNA进行荧光定量PCR验证,结果证实了测序数据的可靠性。【结论】mi RNA通过负调控靶标转录因子和激素相关基因来影响纤维细胞的起始发育。

[Objective] The yield and quality of fiber were investigated by fiber initiation on the surface of cotton ovules. Thus, it is necessary to investigate the small RNAs related to fiber initiation and their target genes to determine the mechanism of fiber initiation.[Methods] In this study, using the Gossypium hirsutum L. genome sequence as the reference, six small RNA libraries were constructed, and high-throughput sequencing was performed using 0 day post anthesis ovules of wild type and fuzzless mutant.[Results] A total of 459 mi RNAs, 301 conserved and 158 novel ones, were identified. In total, 13 differentially expressed mi RNAs were obtained, and their target genes were predicted and analyzed. A bioinformatics analysis of the target genes revealed that a majority of transcription factors encode homeodomain-leucine zippers, GRAS(Gibberellic acid insensitive, Repressor of GAI, Scarecrow) and APETALA2 families, and their functions were concentrated in the transcriptional and post-transcriptional regulatory stages. Gene ontology annotations of the target genes revealed that they are involved in cell differentiation, anther development and floral organ development. Four mi RNAs were randomly selected for a fluorescence quantitative polymerase chain reaction analysis, and the results confirmed the reliability of the sequencing data.[ Conclusion] mi RNAs regulated the initiation and development of fiber cells by targeting transcription factors and phytohormone-related genes.