The role of histone modifications in Fusarium oxysporum pathogenicity

组蛋白修饰在尖孢镰刀菌致病性中的作用

• 批准号: 408033566
• 负责人: Dr. Slavica Janevska
• 金额: --
• 依托单位: Nachwuchsgruppe (Epi-)Genetische Regulation Pilzlicher Virulenz
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/408033566?language=en
• 关键词: role; histone; modifications; Fusarium; oxysporum

Host-specific forms (formae speciales, f. sp.) of Fusarium oxysporum cause vascular wilt disease on a broad range of agronomically relevant crops. Individual strains have a narrow host range, and infection relies on a specific set of small secreted proteins, i.e. effectors. Genome sequencing of the tomato pathogen F. oxysporum f. sp. lycopersici (Fol) revealed eleven conserved core chromosomes and four lineage-specific, accessory chromosomes. Lineage-specific chromosome 14 harbors all SIX (secreted in xylem) effector genes required for pathogenicity.Unpublished experiments have indicated that Fol lineage-specific regions constitute facultative heterochromatin. Such regions are especially diverse among Fusarium species or among f. sp. of F. oxysporum, and transcriptionally silent in general. In Fusarium fujikuroi, facultative heterochromatin is characterized by the histone (H) lysine (K) modifications H3K36me3 and H3K27me3. I have shown that depletion of FfAsh1-mediated H3K36me3 resulted in an accumulation of repressive H3K27me3, and in frequent loss of the respective regions (subtelomeres, accessory chromosome). These mechanisms will be further studied in Fol, especially concerning the stability of lineage-specific regions, and the influence on pathogenicity and effector gene expression in planta.Furthermore, the transcription factor Sge1 (SIX gene expression 1) is required for expression of most effector genes, and is therefore essential for Fol pathogenicity. The role of FoSge1 in the chromatin-level regulation of SIX genes will be assessed, by testing H3 methylation and acetylation marks in FoSGE1 mutants.

寄主特异性形式（formae speciales，f. sp.）尖孢镰刀菌（Fusarium oxysporum）的病原体在广泛的农艺学相关作物上引起维管枯萎病。单个菌株具有狭窄的宿主范围，并且感染依赖于一组特定的小分泌蛋白，即效应物。番茄致病菌F. oxysporum F. sp. lycopersici（Fol）的核心染色体有11条保守的核心染色体和4条谱系特异的辅助染色体。谱系特异性染色体14含有致病性所需的所有SIX（分泌在木质部中）效应基因。未发表的实验表明Fol谱系特异性区域构成兼性异染色质。这些区域在镰刀菌属物种之间或在f. sp.）的F.尖孢菌，并且通常转录沉默。在藤仓镰刀菌中，兼性异染色质的特征在于组蛋白（H）赖氨酸（K）修饰H3K36me3和H3K27me3。我已经证明，FfAsh1介导的H3 K36 me3的缺失会导致抑制性H3 K27 me3的积累，并导致相应区域（亚端粒、辅助染色体）的频繁丢失。这些机制将在Fol中进一步研究，特别是谱系特异性区域的稳定性，以及对植物致病性和效应基因表达的影响。此外，转录因子Sge 1（SIX gene expression 1）是大多数效应基因表达所必需的，因此对Fol的致病性至关重要。FoSge 1在SIX基因的染色质水平调节中的作用将通过测试FoSge 1突变体中的H3甲基化和乙酰化标记来评估。