禾生指梗霉菌侵染对谷子幼穗分化及发育的影响  

Impact of Sclerospora graminicola infection on spikelet differentiation and development of foxtail millet(Setaria italica L.)

作　　者：张宝俊[1,2] 张育铭 孙卓楠 付振鑫 徐林 韩渊怀 ZHANG Baojun;ZHANG Yuming;SUN Zhuonan;FU Zhenxin;XU Lin;HAN Yuanhuai(College of Plant Protection,Shanxi Agricultural University,Taigu 030801,China;Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding,Taiyuan 030031,China)

机构地区：[1]山西农业大学植物保护学院,太谷030801 [2]山西省杂粮种质创新与分子育种重点实验室,太原030031

出　　处：《植物病理学报》2023年第4期679-689,共11页Acta Phytopathologica Sinica

基　　金：国家重点研发计划(2018YFD1000703、2018YFD100070);山西省自然基金面上项目(20210302123415)。

摘　　要：谷子白发病是由病原卵菌禾生指梗霉(Sclerospora graminicola)引起的一种严重影响谷子生产的土传病害。在谷穗生长锥伸长期,禾生指梗霉侵染扩展至谷子穗部可导致谷穗分化发育受阻,形成畸形穗。为解析禾生指梗霉侵染影响谷子幼穗分化及发育的分子基础,本研究观测了受侵染谷穗在生长锥突起期(S1)至雌雄蕊分化期(S5)的形态变化,借助RNA-seq分析谷子穗部响应禾生指梗霉侵染的差异表达基因及关键调控因素,并通过LC-MS/MS测定病穗中生长素的含量变化。研究结果表明,受侵染谷穗在生长锥突起期发育受阻,枝梗分化期无明显一级、二级指梗分化特征;共有336个基因在谷穗发育不同时期(S1~S5)均差异表达,显著富集在激素介导的信号通路、激素水平调节、激素代谢过程、激素生物合成过程等GO通路,通过KEGG也富集到色氨酸代谢、类胡萝卜生物合成、玉米素生物合成等与激素生物合成相关的途径,其中在色氨酸代谢通路富集到328个基因;IAA生物合成通路与转运通路相关调控基因表达量上调,而在IAA信号转导通路相关基因表达量下降。在S4时期病穗中生长素含量显著高于对照组,IAA处理可促进菌丝的生长发育。研究结果表明:禾生指梗霉可能通过调控寄主体内生长素的合成促进病原菌向谷子生长点进一步侵染和扩展。Downy mildew caused by the oomycete pathogen Sclerospora graminicola,is a soil-borne disease,which resulting in serious grain yield losses to foxtail millet production.Panicles are often infected by S.graminicola at the growth cone extension stage,and therefore the differentiation and development of spikelets are hindered with subsequently displaying deformation.Regarding the morphological changes in panicles through the growth cone protrusion stage(S1)to the pistil and stamen differentiation stage(S5)with challenging of the oomycete infection,the aim of the present study was to investigate the underlying molecular mechanisms with the transcription profiling of differentially expressed genes and key regulatory factors association with pathogen infection through RNA-seq,while changes in auxin contents of panicles were determined using LC-MS/MS.According to the results,panicle development was inhibited at the growth cone protrusion stage,and no obvious characteristics of primary and secondary branches were observed at the panicle branch differentiation stage.A total of 336 differentially expressed genes(DEGs)were simultaneously associated with the five developmental stages(S1~S5)of panicles,which significantly enriched in the hormone-mediated signal pathway,hormone level regulation,hormone metabolism process,and hormone biosynthesis process with Gene Ontology(GO)analysis,while Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis revealed the pathways mainly related to hormone biosynthesis,such as tryptophan metabolism,carotenoid biosynthesis,and zeatin biosynthesis.Among them,328 genes involved in tryptophan metabolism were enriched.In addition,genes involved in indole-3-acetic acid(IAA)biosynthesis and transport pathways were up-regulated;however,genes related to IAA signal transduction were down-regulated.The auxin contents of the panicles were significantly increased following the infection of S.graminicola at the S4 stage,and IAA treatment in vitro promoted S.graminicola mycelium development.In sum,S.graminico

关 键 词：谷子 禾生指梗霉菌 幼穗分化 转录组 生长素 

分 类 号：S432.1[农业科学—植物病理学]