干旱胁迫下芋叶片转录组分析

Transcriptome analysis of taro(Colocasia esculenta)leaves under drought stress

  • 摘要: 【目的】 明确芋叶片响应干旱胁迫的关键通路与相关基因,分析芋叶片在干旱胁迫下的基因表达模式并探究芋叶片对干旱胁迫的分子响应机制,为阐明芋响应干旱调控分子机制及选育不同耐旱性芋品种提供参考。【方法】 以荔浦芋为试验材料,连续7 d干旱处理后采集的叶片样品为处理组,以每天浇水的叶片样品为对照组,进行转录组测序;筛选差异表达基因(DEGs),并对DEGs进行GO功能注释分析和KEGG信号通路富集分析。【结果】 在干旱胁迫下,共筛选到DEGs 1613个,其中上调DEGs 1043个,下调DEGs 570个。GO功能注释分析结果表明,DEGs注释到分子功能、细胞组分和生物活动三大功能类别;在分子功能中,DEGs主要注释到结合和催化活性功能条目;在细胞组分中,DEGs主要注释到细胞解剖实体和含蛋白质复合物功能条目;在生物活动中,DEGs主要注释到细胞过程和代谢过程功能条目。KEGG信号通路富集分析结果表明,85.00% DEGs富集在新陈代谢通路。而在新陈代谢通路中,DEGs主要富集到谷胱甘肽代谢及淀粉和蔗糖代谢通路,分别筛选出DEGs 11和19个。在干旱胁迫下,共筛选出112个差异表达转录因子,主要包括bHLH、ERF、WRKY和NAC家族转录因子。在所有差异表达转录因子中,82.14%的转录因子家族成员在干旱胁迫下转录水平上调。激素信号转导、类胡萝卜素生物合成和MAPK信号通路是脱落酸响应干旱的关键通路,影响芋叶片气孔关闭和种子休眠,从而响应干旱胁迫。实时荧光定量PCR结果表明转录组测序数据可靠。【结论】 干旱胁迫下,芋叶片中谷胱甘肽通路、淀粉和蔗糖代谢通路及转录因子基因表达受影响,大部分转录因子对芋干旱起正向调控作用。

     

    Abstract: 【Objective】 This study aimed to clarify the key pathways and related genes of taro leaves in response to drought stress,analyze the gene expression patterns under drought conditions,and explore the molecular response mechanisms. The findings would provide theoretical references for understanding the molecular mechanisms of taro’s drought regulation and for breeding different drought tolerant taro varieties in the future. 【Method】 Using Lipu taro as the experimental material,leaf samples were collected after consecutive 7 d of drought treatment as the treatment group,while leaf samples from plants watered daily served as the control group. Transcriptome sequencing was performed to identify differentially expressed genes,which were then subjected to GO functional annotation and KEGG pathway enrichment analysis. 【Result】 Under drought stress,there were 1613 differentially expressed genes(DEGs),including 1043 up-regulated and 570 down-regulated genes. GO functional annotation analysis revealed that the DEGs were categorized into three major functional groups:molecular function,cellular component,and biological process. In the molecular function category,DEGs were annotated to binding and catalytic activity. In the cellular component category,DEGs were annotated to cellular anatomical entities and protein-containing complexes. In the biological process category,DEGs were annotated to cellular processes and metabolic processes. KEGG signaling pathway enrichment analysis showed that 85.00% of the DEGs were enriched in metabolic pathway. Among these,the DEGs were primarily enriched in the glutathione metabolism pathway and the starch and sucrose metabolism pathway,with 11 and 19 DEGs identified in each pathway respectively. Under drought stress,a total of 112 differentially expressed transcription factors (TFs) were identified, mainly including members of the bHLH,ERF,WRKY and NAC families. Among all differentially expressed TFs, 82.14% showed up-regulated transcription levels under drought conditions. Plant hormone signal transduction,carotenoid biosynthesis,and the MAPK signaling pathway-plant were identified as key abscisic acid-responsive pathways involved in drought response,influencing stomatal closure in taro leaves and seed dormancy to cope with drought stress. The relia-bility of the transcriptome data was confirmed by quantitative real-time PCR analysis. 【Conclusion】 Under drought stress, the gene expression in the glutathione metabolism pathway,the starch and sucrose metabolism pathway,and transcription factors in taro leaves is affected. Most TFs are positively involved in regulating taro plant’s drought response.

     

/

返回文章
返回