Functional genomic analyses of environmental signaling in Trichoderma reesei

Abstract

Life of most organisms is dominated by nutrient availability, the need for reproduction and the rotation of the earth which results in daily changes between light and darkness. Therefore, the molecular machinery for environmental sensing of the biotechnological workhorse Trichoderma reesei (Hypocrea jecorina) shall be dissected using cellulase gene expression and sexual development as model output pathways under controlled light conditions. Crucial factors for these processes are on the one hand genes involved in signal perception, most prominently represented by the G-protein coupled receptors, and on the other hand kinases and phosphatases, which represent signal transmitters to the respective target promotors. One crucial aim of this thesis is the elucidation of the connection of nutrient signaling with recognition of a potential mating partner and initiation of sexual development. Although it is well known that a deteriorating environment - especially lack of appropriate nutrient conditions - is beneficial for initiation of sexual development, this interrelationship has not been investigated with respect to interconnections to signaling pathways in that much detail. The first comprehensive subset of gene knock out strains of a specific group of genes shall be provided along with an initial functional characterization in T. reesei. Investigation of the influence of signaling genes on sexual development as well as including genes known to be involved in sexual development in T. reesei will allow us to identify crossroads and checkpoints of the interrelationship between sexual development and environmental signaling. Consequently, we will not only apply high throughput gene knock-out for the first time in T. reesei at a large scale. With our case study we will also provide crucial insights into physiological relevance of signal transducing proteins at a broad range. The obtained data will also represent an invaluable basis and resource for research with signal transduction in fungi as well as for the industrial application of these organisms.