转录组分析马缨杜鹃响应高温胁迫的分子机制

Transcriptome analysis of the molecular mechanism of Rhododendron delavayi responding to high temperature stress

关键词:  马缨杜鹃, 高温胁迫, 转录组, 差异表达基因, 转录因子

Key words:  Rhododendron delavayi, high temperature stress, transcriptome, differentially expressed genes(DEGs), transcription factors

摘要:

为探究马缨杜鹃幼苗响应高温胁迫的分子机制,该研究以马缨杜鹃幼苗为实验材料进行高温胁迫处理,RNA-seq分析筛选差异表达基因并进行GO和KEGG富集分析,鉴定显著富集的信号通路和转录因子。结果表明:(1)对高温胁迫处理下马缨杜鹃叶片转录组进行分析,共获得90.54 Gb Clean Data,差异表达基因分析发现,高温胁迫3 d和6 d共同表达的差异基因有5 435个。(2)对5 435个差异基因进行GO富集分析,高温胁迫3 d差异表达基因主要富集在有机物合成、响应刺激、脂质代谢过程等生理过程中; 高温胁迫6 d差异表达基因主要富集在磷代谢过程、磷酸化、质膜等生理过程中。(3)KEGG富集分析发现,高温胁迫3 d和6 d共同表达的差异基因主要富集在次生代谢产物的生物合成、淀粉和蔗糖代谢、植物激素信号转导等通路中。(4)植物激素信号转导通路分析表明,高温胁迫整体上调了脱落酸(ABA)、茉莉酸(JA)和水杨酸(SA)的信号转导通路。(5)鉴定出一系列响应高温胁迫的转录因子(NAC、MYB 、WRKY 和bHLH),这些转录因子可能在马缨杜鹃应对高温胁迫中发挥重要功能。该研究表明高温胁迫诱导马缨杜鹃叶片相关基因和转录因子的表达,促进植物激素信号转导途径,从而响应高温胁迫,该研究结果有助于进一步了解马缨杜鹃的热胁迫响应调控机制,并为创制耐热性更强的品种提供理论依据与基因资源。

Abstract:

In order to investigate the molecular mechanisms underlying the response of Rhododendron delavayi seedlings to high-temperature stress, we performed RNA-seq analysis on R. delavayi seedlings treated at high temperatures to identify differentially expressed genes(DEGs). Then, we performed Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses to identify significantly enriched signaling pathways and transcription factors. The results were as follows:(1)We obtained 90.54 Gb of clean data from the transcriptome analysis of R. delavayi leaf samples, and by analyzing the DEGs, and identified 5 435 genes that were differentially expressed after three and six days of high-temperature stress.(2)We performed GO enrichment analysis of the identified DEGs and found that genes differentially expressed after three days of high-temperature stress were primarily enriched in physiological processes such as organic matter synthesis, response to stimuli, and lipid metabolism. In contrast, genes differentially expressed after six days of high-temperature stress were mainly enriched in processes related to phosphorus metabolism, phosphorylation, and plasma membrane function.(3)Through KEGG enrichment analysis, we found that the DEGs after three and six days of high-temperature stress were predominantly enriched in pathways related to biosynthesis of secondary metabolites, starch and sucrose metabolism, and plant hormone signal transduction.(4)By analyzing the plant hormone signal transduction pathway, we found that high-temperature stress triggered an overall upregulation of abscisic acid(ABA), jasmonic acid(JA), and salicylic acid(SA)signaling pathways.(5)Furthermore, we identified several transcription factor families, including NAC, MYB, WRKY, and bHLH, as potential key regulators of the response of R. delavayi to heat stress. These results enhance our understanding of the regulatory mechanisms underlying heat stress tolerance in R. delavayi and provide a theoretical reference and genetic resources for developing more heat-tolerant cultivars.