ghr-miR160负调控棉花叶片衰老机理研究

ghr-miR160, a Class of Gossypium hirsutum L. MicroRNA, Negatively Regulates the Progress of Leaf Senescence

【目的】陆地棉(Gossypium hirsutum L.)叶片早衰会导致棉花减产降质。MicroRNA(miRNA)是1类长度约为21 nt、在转录后水平调节基因表达的内源非编码小分子RNA。研究ghr-miR160对叶片衰老的调控具有重要意义。【方法】对ghr-miR160进行生物信息学分析、棉花子叶表达模式分析及过表达载体转化拟南芥验证分析。【结果】对ghr-miR160及pre-miR160结构分析表明,miR160在进化过程中高度保守。qRT-PCR结果显示,ghr-miR160在生长35 d的早熟不早衰品种辽4086子叶中优势表达。农杆菌介导转化拟南芥发现,该基因可使拟南芥出现晚抽薹、晚开花和叶片衰老延迟现象。【结论】ghr-miR160可能对棉花叶片衰老起负调控作用,同时为进一步阐明其作用机制奠定了基础。

[Objective]For Gossypium hirsutum L.,leaf premature senescence leads to reduced yield and quality.MicroRNA(miRNA)is a class of endogenous,non-coding small RNA,about 21 nucleotides in length,which regulates gene expression at the post-transcriptional level.This study aimed to investigate the effect of ghr-miR160 in regulating leaf senescence.[Method]ghr-miR160 bioinformatics analysis,expression pattern analysis in cotton cotyledons,and overexpression experiments in Arabidopsis were conducted.[Result]Multiple sequence alignment and phylogenetic analysis revealed that ghr-miR160 was highly conserved during evolution.Real-time quantitative reverse transcription polymerase chain reaction showed that ghr-miR160 was upregulated in 35-day-old cotyledons of Liao 4086(early maturity without senescence).The transgenic carrying ghr-miR160 showed delayed leaf senescence,and increased blotting time,leading to late flowering.[Conclusion]These results confirmed that ghr-miR160 could delay leaf senescence,which provided a foundation for elucidating its functional mechanism.