Functional Analysis of Mating Type Genes and Transcriptome Analysis during Fruiting Body Development of Botrytis cinerea.
Functional Analysis of Mating Type Genes and Transcriptome Analysis during Fruiting Body Development of Botrytis cinerea.
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DOI：
10.1128/mbio.01939-17
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发表时间：
2018-02-13
期刊：
影响因子：
6.4
通讯作者：
van Kan JAL
中科院分区：
文献类型：
--
作者：
Rodenburg SYA;Terhem RB;Veloso J;Stassen JHM;van Kan JAL
灰葡萄孢（Botrytis cinerea）是一种植物病原真菌，有性子实体为灰霉病菌。为了研究交配型（MAT）基因的功能，在MAT 1 -1位点的两个基因和MAT 1 -2位点的两个基因中产生单基因缺失突变体。两个MAT基因的缺失突变体是完全不育的，而其他两个MAT基因的突变体能够发展柄，但从来没有形成一个apothecial盘。在子囊盘发育过程中基因表达的重编程知之甚少。我们分析了转录组的菌核，三个阶段的子囊盘发展（原基，柄，和子囊盘），和子囊孢子的RNA测序。10个次级代谢产物基因簇在性发育开始时上调，在子囊孢子中下调。值得注意的是，超过3，900个基因在子囊孢子中与成熟的子囊盘相比差异表达。在子囊孢子中上调的基因中有许多编码毒力因子的基因，这表明子囊孢子在到达宿主植物之前在转录上被引发感染。引人注目的是，性周期开始和结束时的大量转录变化通常影响基因簇，而不是随机分散的基因。在有性生殖开始期间，35个基因簇联合上调，而99个基因簇（包含>900个基因）在子囊孢子中联合下调。这些转录变化与编码参与染色质组织的酶的基因表达的变化相吻合，暗示有性生殖过程中基因表达的大规模表观遗传调控的发生。真菌子实体是通过有性生殖形成的。我们研究了普遍存在的植物病原性子囊菌灰葡萄孢的子实体（“apotherapy”）的发展。通过定点突变的方法研究交配型基因在子囊盘发育中的作用。有两个基因对于性发育的启动是必不可少的;这些基因的突变体是不育的。另外两个基因对菌柄的发育不是必需的，但是，它们对菌柄发育成盘和产生有性子囊孢子是必需的。我们研究了子囊盘发育过程中的基因表达谱，以及从子囊盘中取样的子囊孢子。我们提供了有史以来第一个研究纯子囊孢子的转录组在丝状真菌。在子囊孢子中诱导了许多参与植物感染的基因的表达，这意味着子囊孢子在从孢子囊中释放之前发育为感染做好准备。
Botrytis cinerea is a plant-pathogenic fungus producing apothecia as sexual fruiting bodies. To study the function of mating type (MAT) genes, single-gene deletion mutants were generated in both genes of the MAT1-1 locus and both genes of the MAT1-2 locus. Deletion mutants in two MAT genes were entirely sterile, while mutants in the other two MAT genes were able to develop stipes but never formed an apothecial disk. Little was known about the reprogramming of gene expression during apothecium development. We analyzed transcriptomes of sclerotia, three stages of apothecium development (primordia, stipes, and apothecial disks), and ascospores by RNA sequencing. Ten secondary metabolite gene clusters were upregulated at the onset of sexual development and downregulated in ascospores released from apothecia. Notably, more than 3,900 genes were differentially expressed in ascospores compared to mature apothecial disks. Among the genes that were upregulated in ascospores were numerous genes encoding virulence factors, which reveals that ascospores are transcriptionally primed for infection prior to their arrival on a host plant. Strikingly, the massive transcriptional changes at the initiation and completion of the sexual cycle often affected clusters of genes, rather than randomly dispersed genes. Thirty-five clusters of genes were jointly upregulated during the onset of sexual reproduction, while 99 clusters of genes (comprising >900 genes) were jointly downregulated in ascospores. These transcriptional changes coincided with changes in expression of genes encoding enzymes participating in chromatin organization, hinting at the occurrence of massive epigenetic regulation of gene expression during sexual reproduction. Fungal fruiting bodies are formed by sexual reproduction. We studied the development of fruiting bodies (“apothecia”) of the ubiquitous plant-pathogenic ascomycete Botrytis cinerea. The role of mating type genes in apothecium development was investigated by targeted mutation. Two genes are essential for the initiation of sexual development; mutants in these genes are sterile. Two other genes were not essential for development of stipes; however, they were essential for stipes to develop a disk and produce sexual ascospores. We examined gene expression profiles during apothecium development, as well as in ascospores sampled from apothecia. We provide the first study ever of the transcriptome of pure ascospores in a filamentous fungus. The expression of numerous genes involved in plant infection was induced in the ascospores, implying that ascospores are developmentally primed for infection before their release from apothecia.