CRC-TRR 175/1: The Green Hub. Central Coordinator of Acclimation in Plants

Plants have evolved a variety of physiological responses that enable them to adjust to changes in their abiotic environment (acclimation). The TR175 focuses on reversible responses to changes that plants will encounter frequently, in particular fluctuations in temperature and light levels. The chloroplast has emerged as a hub of acclimation to fluctuations in light and temperature and serves both, as sensor for and target of acclimation. The TR175 links scientists from Munich, Kaiserslautern and Berlin/Golm with an outstanding range of expertise in chloroplast biology in the three model species Arabidopsis, tobacco, and Chlamydomonas. In the first funding period, the TR175 has focused on the identification and characterisation of key factors (modulators and integrators) in acclimation to cold, heat and high light. Modulators are acclimation components whose loss affect acclimation responses, while integrators represent modulators that coordinate at least two acclimation processes. Quantitative experimentation joined with system-biology approaches pervaded the entire research network, providing a high synergy between physiological, biochemical and system-biology approaches. In the second funding period, we will continue research in the four major research areas of the TR175. In Area A we will characterize genetic modulators of acclimation. Insights from the first funding period have prompted us to shift our focus towards studies on the regulation of chloroplast translation and to extend our analysis to longer acclimation periods. In Area B we will continue to characterise metabolic modulators by quantitative analyses. In addition, we will include fluctuating light conditions in our portfolio of environmental factors. In Area C we will continue to characterize signalling modulators in more detail, and extend our attention to the nucleocytosolic compartment, as well as to environmental factors like drought and fluctuating light. In Area D we will continue to design and employ efficient algorithms, as well as sophisticated tools for data structuring and interpretation, with the goal of computer-based modelling of metabolic reaction sequences, signal transduction pathways and gene-regulatory networks during acclimation. Our Central Scientific Project Z1 will further serve as central resource for quantitative-biology approaches and it will be extended to identify novel modulators and integrators based on laboratory evolution approaches. Modulators/Integrators identified will then be directly tested in the four research areas and will be transferred into the model crop Camelina sativa.The expected outcomes will comprehensively elucidate the factors and mechanisms behind the chloroplast’s centrality within the broader context of acclimation, allowing us to effectively identify genetic factors with a high potential to enhance acclimation ultimately in crop plants.