Department of Plant Pathology and Weed Research, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel.
The Robert H. Smith Faculty of Agriculture, The Hebrew University of Jerusalem, Food & Environment, Rehovot, Israel.
BMC Genomics. 2024 Oct 2;25(1):917. doi: 10.1186/s12864-024-10824-y.
The fungus Metarhizium brunneum has evolved a remarkable ability to switch between different lifestyles. It develops as a saprophyte, an endophyte establishing mutualistic relationships with plants, or a parasite, enabling its use for the control of insect pests such as the aphid Myzus persicae. We tested our hypothesis that switches between lifestyles must be accompanied by fundamental transcriptional reprogramming, reflecting adaptations to different environmental settings.
We combined high throughput RNA sequencing of M. brunneum in vitro and at different stages of pathogenesis to validate the modulation of genes in the fungus and its host during the course of infection. In agreement with our hypothesis, we observed transcriptional reprogramming in M. brunneum following conidial attachment, germination on the cuticle, and early-stage growth within the host. This involved the upregulation of genes encoding degrading enzymes and gene clusters involved in synthesis of secondary metabolites that act as virulence factors. The transcriptional response of the aphid host included the upregulation of genes potentially involved in antifungal activity, but antifungal peptides were not induced. We also observed the induction of a host flightin gene, which may be involved in wing formation and flight muscle development.
The switch from saprophytic to parasitic development in M. brunneum is accompanied by fundamental transcriptional reprogramming during the course of the infection. The aphid host responds to fungal infection with its own transcriptional reprogramming, reflecting its inability to express antifungal peptides but featuring the induction of genes involved in winged morphs that may enable offspring to avoid the contaminated environment.
真菌玫烟色棒束孢已经进化出一种在不同生活方式之间切换的非凡能力。它可以作为腐生物、与植物建立互利关系的内共生体或寄生虫发育，从而使其能够用于控制如桃蚜等昆虫害虫。我们验证了一个假设，即生活方式的转变必须伴随着基本的转录重编程，以反映对不同环境的适应。
我们结合了玫烟色棒束孢在体外和不同发病阶段的高通量 RNA 测序，以验证在感染过程中真菌及其宿主基因的调节。与我们的假设一致，我们观察到在分生孢子附着、在表皮上萌发以及在宿主内早期生长后，玫烟色棒束孢发生了转录重编程。这涉及到降解酶基因和参与合成作为毒力因子的次生代谢物的基因簇的上调。蚜虫宿主的转录反应包括可能参与抗真菌活性的基因的上调，但未诱导抗真菌肽。我们还观察到宿主飞行蛋白基因的诱导，它可能参与翅膀形成和飞行肌肉发育。
玫烟色棒束孢从腐生到寄生发育的转变伴随着感染过程中的基本转录重编程。蚜虫宿主对真菌感染的反应是其自身的转录重编程，反映了它不能表达抗真菌肽，但诱导了与有翅形态相关的基因，这可能使后代能够避免受污染的环境。
