Page 124 - 《广西植物》2025年第11期
P. 124

2 0 6 8                                广  西  植  物                                         45 卷
                 identify differentially expressed genes (DEGs). Thenꎬ 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 samplesꎬ and by analyzing the DEGsꎬ 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 synthesisꎬ response to stimuliꎬ and lipid metabolism. In contrastꎬ genes
                 differentially expressed after six days of high ̄temperature stress were mainly enriched in processes related to phosphorus
                 metabolismꎬ phosphorylationꎬ and plasma membrane function. (3) Through KEGG enrichment analysisꎬ we found that
                 the DEGs after three and six days of high ̄temperature stress were predominantly enriched in pathways related to
                 biosynthesis of secondary metabolitesꎬ starch and sucrose metabolismꎬ and plant hormone signal transduction. (4) By
                 analyzing the plant hormone signal transduction pathwayꎬ we found that high ̄temperature stress triggered an overall
                 upregulation of abscisic acid ( ABA)ꎬ jasmonic acid ( JA)ꎬ and salicylic acid ( SA) signaling pathways. ( 5)
                 Furthermoreꎬ we identified several transcription factor familiesꎬ including NACꎬ MYBꎬ WRKYꎬ and bHLHꎬ 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.
                 Key words: Rhododendron delavayiꎬ high temperature stressꎬ transcriptomeꎬ differentially expressed genes (DEGs)ꎬ
                 transcription factors




                马缨杜鹃(Rhododendron delavayi) 隶属于杜鹃              较多ꎮ 当气温高于 35 ℃ 时ꎬ马缨杜鹃停止营养生
            花科( Ericaceae) 杜鹃花属( Rhododendron) 常绿杜             长ꎬ进入半休眠期(汪蓉等ꎬ2015)ꎮ 持续的高温天
            鹃亚属( Hymenanthes)ꎬ花朵硕大猩红ꎬ花期早且                      气ꎬ还会导致其叶片出现黄化、萎蔫、枯焦等“ 日
            长ꎬ在我国具有悠久的栽培历史ꎬ同时在国际花卉                             灼”现象ꎮ 同时ꎬ高温胁迫诱导马缨杜鹃细胞产生
            市场也享有盛名( 吴福建等ꎬ2008)ꎮ 马缨杜鹃具                         大量活性氧ꎬ造成细胞内核酸、蛋白质和脂质等生
            有极高的观赏、经济、科学和生态价值ꎬ还具有药                             物大分子的氧化性损伤ꎬ最终引起细胞凋亡甚至

            用、食用和工 业 价 值 ( 段 旭 等ꎬ2007aꎻ徐 金 金 等ꎬ                坏死( 梁雯等ꎬ2018)ꎮ 此外ꎬ秋季温度过高ꎬ抑制
            2012ꎻ刘德团等ꎬ2020)ꎮ 作为重要的原始育种亲                        营养生长和花芽分化ꎬ甚至出现“ 成花逆转” 现象ꎬ
            本ꎬ马缨杜鹃在杜鹃花育种史上占据重要地位ꎬ但                             导致花芽败育ꎬ严重影响马缨杜鹃的观赏价值( 岳
            杜鹃花偏爱凉爽湿润的气候ꎬ耐热性较差ꎬ高温严                             保超ꎬ2015)ꎮ 综上表明ꎬ全球气候变暖改变了马

            重制 约 了 其 推 广 应 用 和 育 种 ( Kumarꎬ 2012 ꎻ             缨杜鹃的生存环境和立地条件ꎬ严重破坏了野生
            Komac et al.ꎬ 2016)ꎮ                               马缨杜鹃种质资源遗传多样性ꎮ
                 近年来ꎬ关于马缨杜鹃的研究主要涉及种苗                               转录组分析现已在各类生物和非生物胁迫的
            生长规律、繁殖技术、花期调控、植物激素对其光                             研究中得到广泛应用ꎬ通过转录组测序已在多种

            合作用日变化的影响( 段旭等ꎬ2007bꎻ李国树等ꎬ                         植物中识别出大量热响应基因及其相关途径ꎬ这
            2011ꎻ徐小蓉等ꎬ2011ꎻ岳保超等ꎬ2016) 及病虫害                     为深入理解植物响应高温胁迫的分子调控机制提
            防治(任纬恒ꎬ2019) 等方面ꎮ 有关马缨杜鹃非生                         供了重要依据( 庞振ꎬ2023)ꎮ 杜鹃叶片在热胁迫

            物胁迫的研究主要集中在水淹( 段盛光等ꎬ2022)、                         下的转录组结果显示ꎬHSP 家族在响应热胁迫过
            干旱和酸碱方面(曾松等ꎬ2023)ꎬ对马缨杜鹃高温                          程中发挥着核心作用( Fang et al.ꎬ 2017)ꎬ KEGG
            胁迫研究则相对较少ꎬ尤其是在基因表达方面ꎮ                              富集分析发现ꎬ光合作用途径在热处理条件下发
            随着全球气候变暖和极端天气的持续频繁出现ꎬ                              生显著变化ꎮ 此外ꎬ海南杜鹃高温胁迫下的转录
            高温胁迫严重阻碍马缨杜鹃正常的生长发育ꎮ 夏                             组分 析 还 发 现 激 素 相 关 基 因 ( 如 生 长 素 中 的
            季温度升高ꎬ植株容易发生徒长ꎬ长势弱ꎬ病虫害                             ARF5ꎬ赤霉素中的 GID1ꎬ脱落酸中的 PYL4) 转录
   119   120   121   122   123   124   125   126   127   128   129