Drought stress priming in filamentous saprotrophic fungi: transcriptomic/proteomic responses and the impact on C mineralisation

• Applicant: Dr. Alexander Guhr
• Subject Area: Soil Sciences
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 370489501

Many microorganisms are often confronted with drought stress, with potentially negative impact on microbial fitness, function or survival. A priming for environmental stressors by retaining information from previous stress incidents can be essential to safeguard survival in a dynamical changing environment. While stress priming has been intensively studied in plants as well as some bacterial and fungal species, saprotrophic filamentous fungi have been mostly neglected so far. Yet, they are major agents of carbon (C) mineralisation in soils and can mineralise C even in very dry soils. Knowledge of the mechanisms regulating stress priming is of great interest for understanding fungal impact on soil biogeochemistry in dry soils. Here, we will investigate, if stress priming influences survival of saprotrophic filamentous fungi under drought stress and how it affects the transcriptional and translational level as well as the mineralisation of litter. Mesocosm experiments will be conducted with an automated irrigation system. The impact of different recovery times between a moderate stress event (priming stress, app. pF 4.5, corresponds to a water potential of about -3.16 MPa) and a severe stress event (triggering stress, app. pF 6, corresponds to a water potential of about -100 MPa) will be tested. Transcriptional and translational responses of the fungi will be analysed by high-density microarray hybridization and MALDI-TOF-mass spectrometry, respectively. The effect of stress priming on the mineralisation will be studied by continuously monitoring the CO2 evolution using the dynamic closed-chamber technique. These experiments will emphasise the role of saprotrophic filamentous fungi for the mineralisation under dry soil conditions.

• DFG Programme: Research Grants