MOE Laboratory of Biosystems Homeostasis & Protection, Institute of Microbiology, College of Life Sciences, Zhejiang Universitygrid.13402.34, Hangzhou, Zhejiang, China.
College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, Zhejiang, China.
mSystems. 2022 Aug 30;7(4):e0031822. doi: 10.1128/msystems.00318-22. Epub 2022 Jul 11.
The central developmental pathway (CDP) activator gene is activated by the upstream genes and - in Aspergillus nidulans. Increasing evidences of fungal genome divergence make it necessary to clarify whether such genetic principles fit Pezizomycotina. Previously, disruption resulted in limited conidiation defect and little effect on the expression of and - in Beauveria bassiana possessing the other FluG-like regulator FlrA. Here, single-disruption (SD) mutants of and double-disruption (DD) mutants of and were analyzed to clarify whether FlrA and FluG are upstream regulators of key CDP genes. Despite similar subcellular localization, no protein-protein interaction was detected between FlrA and FluG, suggesting mutual independence. Three SD mutants showed phenotypes similar to those previously described for Δ, including limited conidiation defect, facilitated blastospore production, impaired spore quality, blocked host infection, delayed proliferation , attenuated virulence, and increased sensitivities to multiple stresses. Three DD mutants resembled the SD mutants in all phenotypes except more compromised pathogenicity and tolerance to heat shock- or calcofluor white-induced stress. No CDP gene appeared in 1,622 and 2,234 genes dysregulated in the Δ and Δ mutants, respectively. The majority (up/down ratio: 540:875) of those dysregulated genes were co-upregulated or co-downregulated at similar levels in the two mutants. These findings unravel novel roles for and in coregulating manifold gene sets vital for fungal adaptation to insect-pathogenic lifestyle and environment but not involved in CDP activation. FluG is a core regulator upstream of central developmental pathway (CDP) in Aspergillus nidulans but multiple FluG-like regulators (FLRs) remain functionally uncharacterized in ascomycetes. Our previous study revealed no role for FluG in the CDP activation and an existence of sole FLR (FlrA) in an insect-pathogenic fungus. This study reveals a similarity of FlrA to FluG in domain architecture and subcellular localization. Experimental data from analyses of targeted single- and double-gene knockout mutants demonstrate similar roles of FrlA and FluG in stress tolerance and infection cycle but no role of either in CDP activation. Transcriptomic analyses reveal that FlrA and FluG coregulate a large number of same genes at similar levels. However, the regulated genes include no key CDP gene. These findings uncover that FlrA and FluG play similar roles in the fungal adaptation to insect-pathogenic lifestyle and environment but no role in the activation of CDP.
中央发育途径（CDP）激活基因被上游基因激活，在构巢曲霉中。越来越多的真菌基因组分化证据表明，这些遗传原则是否适用于子囊菌门需要澄清。此前，破坏导致有限的分生孢子缺陷，对 Beauveria bassiana 中其他 FluG 样调节剂 FlrA 的 和 -的表达影响很小。在这里，分析了 和 的单突变体（SD）突变体和 的双突变体（DD）突变体，以阐明 FlrA 和 FluG 是否是关键 CDP 基因的上游调节剂。尽管具有相似的亚细胞定位，但未检测到 FlrA 和 FluG 之间的蛋白质-蛋白质相互作用，表明它们相互独立。三个 SD 突变体表现出与先前描述的 Δ 相似的表型，包括有限的分生孢子缺陷、促进芽生孢子产生、受损孢子质量、阻断宿主感染、延迟增殖、减弱毒力和对多种应激的敏感性增加。三个 DD 突变体在所有表型上与 SD 突变体相似，除了致病性降低和对热休克或 Calcofluor White 诱导的应激的耐受性降低。在 Δ 和 Δ 突变体中，分别有 1,622 和 2,234 个基因失调，而在 CDP 基因中没有出现。在两个突变体中，大多数（上调/下调比：540:875）失调基因以相似的水平共同上调或共同下调。这些发现揭示了 在核心调控多个对真菌适应昆虫致病生活方式和环境至关重要的基因集方面的新作用，但不涉及 CDP 激活。FluG 是构巢曲霉中央发育途径（CDP）的核心调节剂，但在子囊菌中仍有多个 FluG 样调节剂（FLRs）的功能尚未得到描述。我们之前的研究表明，FluG 在 CDP 激活中没有作用，并且在一种昆虫致病真菌中存在唯一的 FLR（FlrA）。这项研究揭示了 FlrA 与 FluG 在结构域结构和亚细胞定位方面的相似性。靶向单基因和双基因敲除突变体分析的实验数据表明，FlrA 和 FluG 在应激耐受和感染周期中具有相似的作用，但在 CDP 激活中没有作用。转录组分析表明，FlrA 和 FluG 以相似的水平共同调控大量相同的基因。然而，受调控的基因不包括关键的 CDP 基因。这些发现表明，FlrA 和 FluG 在真菌适应昆虫致病生活方式和环境方面发挥相似的作用，但在 CDP 激活中没有作用。
