About the TRR 175
The acquisition of the capability to exercise photosynthesis made the characteristically sessile life-style of plants possible. This in turn meant that plants have had to evolve a variety of physiological responses (acclimation) to cope with the considerable fluctuations that may arise in their immediate environment. Acclimation is a complex process, requiring cellular reorchestration of metabolic and genetic activities after the onset of the external stimulus.
Here, we consider fully reversible responses to changes in temperature and light level that plants will encounter frequently at the level of both shortterm (minutes to hours) and long-term (days). It is clear that the organelle is indeed a “hub of acclimation”, serving as both a key sensor of, and target for genetic, proteomic and metabolic adjustments in plants.
The CRC/Transregio links scientists in three locations – Munich, Kaiserslautern and Berlin/Golm – who together bring a remarkable range of expertise in the genetics, molecular biology and biochemistry of chloroplasts, and their interactions with other cell compartments, to bear on the issue. Acclimation depends on various types of modulators, which are defined as components of acclimation reactions whose loss results in altered responses to acclimation stimuli. Integrators are modulators that coordinate at least two acclimation processes.
The first examples of modulators and integrators have already been identified by members of the CRC/Transregio. We will address the complexity of cellular acclimation networks by applying methodologies drawn from quantitative biology to three photosynthetic model organisms, and have identified four major research areas for the CRC/Transregio.
In Area A (Genetic Modulators) we will focus on the quantification of chloroplast gene expression and its dynamics. In Area B (Metabolic Modulators) we will concentrate on readouts of dynamic metabolic adjustments in chloroplasts and related extraplastidial metabolic processes. In Area C (Signalling) we will address the quantitative characterisation of signalling pathways and networks that convey information both within the chloroplast and to the other cellular compartments beyond it. In Area D (Data Mining and Modelling) we have the midterm goal of computerbased modelling of acclimation processes at the cellular level. Furthermore, in our central scientific service project Z1 we will pool our efforts to analyse on a systemwide level the changes that occur during acclimation processes.
The expected outcomes of our consortium will comprehensively elucidate the chloroplast’s centrality within the broader context of acclimation to continuously varying environmental challenges. Our ultimate goal is to predictably modify the cellular networks that mediate acclimation under natural conditions and to contribute, in the long term, to “smart breeding” methods devoted to the creation of crop plants with improved acclimation properties.