Project Details
Projekt
Comparative quantitative analysis of the chloroplast translation apparatus and its dynamic behavior in a green alga and land plants
Subject Area
Plant Biochemistry and Biophysics
Term
from 2020 to 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 437345987
Chloroplast gene expression is a fascinating process with remarkable features. In particular, it is predominantly regulated via highly dynamic post-transcriptional mechanisms. This dynamic regulation is essential for the coordinated integration of nucleus- and chloroplast-encoded subunits, which together constitute key complexes in photosynthetic light reactions, carbon fixation, gene expression and metabolism. Such highly dynamic control is further crucial for plant viability, development, and adaptation to environmental cues. While sequences of many chloroplast-encoded proteins are highly homologous between photosynthetically active species, strategies for mRNA maturation and translation regulation display remarkable differences especially between algae and land plants. We and others accumulated evidence that protein synthesis via plastidic ribosomes is maybe the central overruling process for controlling and tuning chloroplast gene expression in various plant species. This agrees with findings from all kingdoms of life, which indicate that the translation machinery itself serves as a regulatory hub and that ribosome heterogeneity and tuned abundances and/or posttranscriptional modifications of isoacceptor tRNAs substantiate this control. Despite the fundamental importance of chloroplast translational regulation, its kinetics, driving mechanisms, and many of the constituents as well as their detailed modes of action are poorly understood. The overall goal of the proposed interdisciplinary project is to gain a holistic quantitative and mechanistic picture of chloroplast translation in plant cells and to globally describe robustness and adaptability of chloroplast translation. We will follow a horizontal approach to assess the evolutionary robustness and adaptability of chloroplast translation by an inter-species comparison of Chlamydomonas reinhardtii, Arabidopsis thaliana, and Nicotiana tabacum. We will complement the horizontal by a vertical approach, where we will directly test robustness and adaptability of protein synthesis in chloroplasts with mutated tRNAs and ribosomal proteins. Protein synthesis is a highly stochastic and dynamic process of which static data alone cannot provide a complete picture. Therefore, based on the experimental data, we will develop a quantitative theoretical framework of chloroplast translation and stochastic computer simulations will enable us to analyze the robustness and adaptability of chloroplast translation beyond the limits of our experimental approaches.Gaining such deep quantitative knowledge of chloroplast translation is not just crucial for understanding the fundamental biochemical processes within chloroplasts but it will also facilitate biotechnological applications that exploit the tremendous potential of metabolic engineering and transgene expression within these organelles.
DFG Programme
Research Grants
