Data_Sheet_1_A Global Analysis of Photoreceptor-Mediated Transcriptional Changes Reveals the Intricate Relationship Between Central Metabolism and DNA Repair in the Filamentous Fungus Trichoderma atroviride.zip

Light provides critical information for the behavior and development of basically all organisms. Filamentous fungi sense blue light, mainly, through a unique transcription factor complex that activates its targets in a light-dependent manner. In Trichoderma atroviride, the BLR-1 and BLR-2 proteins constitute this complex, which triggers the light-dependent formation of asexual reproduction structures (conidia). We generated an ENVOY photoreceptor mutant and performed RNA-seq analyses in the mutants of this gene and in those of the BLR-1, CRY-1 and CRY-DASH photoreceptors in response to a pulse of low intensity blue light. Like in other filamentous fungi BLR-1 appears to play a central role in the regulation of blue-light responses. Phenotypic characterization of the Δenv-1 mutant showed that ENVOY functions as a growth and conidiation checkpoint, preventing exacerbated light responses. Similarly, we observed that CRY-1 and CRY-DASH contribute to the typical light-induced conidiation response. In the Δenv-1 mutant, we observed, at the transcriptomic level, a general induction of DNA metabolic processes and strong repression of central metabolism. An analysis of the expression level of DNA repair genes showed that they increase their expression in the absence of env-1. Consistently, photoreactivation experiments showed that Δenv-1 had increased DNA repair capacity. Our results indicate that light perception in T. atroviride is far more complex than originally thought.

光线几乎为所有生物的行为与发育提供了关键信息。丝状真菌主要通过一类独特的转录因子复合物（transcription factor complex）感知蓝光，该复合物可依光依赖性方式激活其靶标基因。在深绿木霉（Trichoderma atroviride）中，BLR-1与BLR-2蛋白即构成该复合物，其可触发光依赖性的无性繁殖结构——分生孢子（conidia）的形成。本研究构建了ENVOY光受体（photoreceptor）突变体，并针对该基因以及BLR-1、CRY-1、CRY-DASH光受体的突变体，开展了低强度蓝光脉冲处理下的RNA测序（RNA-seq）分析。与其他丝状真菌的情况类似，BLR-1似乎在蓝光响应调控中发挥核心作用。对Δenv-1突变体的表型表征结果显示，ENVOY可作为生长与分生孢子形成的检查点，避免光响应过度激活。类似地，本研究发现CRY-1与CRY-DASH参与调控典型的光诱导分生孢子形成响应。在Δenv-1突变体中，转录组水平上可见DNA代谢过程普遍上调，而中枢代谢则受到显著抑制。对DNA修复基因表达水平的分析显示，在env-1缺失的情况下，这些基因的表达水平显著升高。与之一致的是，光复活实验结果表明Δenv-1突变体的DNA修复能力有所提升。本研究结果表明，深绿木霉的光感知机制远比此前认知的更为复杂。