Transcriptomic of Beauveria bassiana during in vitro blastospore production

Culturing the entomopathogenic fungus Beauveria bassiana under high glucose concentrations coupled with high aeration results in a fungal developmental shift from hyphae growth to mostly blastospores (yeast-like cells). The underlying molecular mechanisms involved in this shift remains elusive. Therefore, this has motivated us to realize a systematic analysis of the differential gene expression to uncover the fungal transcriptomic response to osmotic and oxidative stresses associated with the resulting high blastospores yield. Differential gene expression was compared under moderate glucose concentration (10% w/v) and high glucose concentration (20% w/v) daily for the three-day culturing. The RNAseq-based transcriptomic results underpinned a higher proportion of down- than up-regulated genes when the fungus was grown under 20% glucose than at 10%. A follow-up study explored a broader glucose range (4, 8, 12, 16, 20% w/v) with phenotype assessment and qRT-PCR of selected genes. Antioxidant, calcium transport, conidiation, and osmosensor related genes were highly up-regulated in higher glucose titers (18-20%) than at lower titers. These findings improved the knowledge of the molecular mechanisms during blastospore development and may help the large scale blastospores industrial production. Overall design: 2 treatments with 3 replicates and sampled at 3 times =18

在高葡萄糖浓度配合高通气条件下培养昆虫病原真菌 Beauveria bassiana，导致真菌发育方向从菌丝生长转变为以接合孢子（酵母样细胞）为主。然而，涉及此转变的潜在分子机制尚不明确。因此，本研究旨在系统地分析差异基因表达，揭示真菌转录组对与高接合孢子产量相关的渗透压和氧化应激的响应。在培养过程中，以中葡萄糖浓度（10% w/v）和高葡萄糖浓度（20% w/v）为处理，每日比较三天的差异基因表达。基于RNAseq的转录组结果显示，在20%葡萄糖浓度下培养的真菌中，下调基因的比例高于上调基因。后续研究进一步探讨了更广泛的葡萄糖浓度范围（4%，8%，12%，16%，20% w/v），结合表型评估和qRT-PCR分析选定基因。抗氧化、钙转运、分生孢子形成和渗透感应相关基因在高葡萄糖浓度（18-20%）下的表达显著高于低浓度。这些发现丰富了我们对接合孢子发育过程中分子机制的认识，并可能有助于大规模接合孢子工业化生产的实现。总体设计：两种处理，每种处理三重复，共三次取样，总计18个样本。