Stress adaptation is crucial for organism survival and is one of the driving forces of biological evolution. Plants are sessile organisms and must therefore continuously cope with various types of stresses imposed by abiotic factors (temperature, light, availability of water, etc.) and pathogens. It is very well documented that these stress-related alterations can have a high impact on crop productivity, limiting yield and resulting in unacceptable economic losses. Therefore, understanding the dynamics and evolution of plant stress response is of fundamental importance as these conditions impact agricultural yield, which is essential to sustain our society. One of the evolutionarily-conserved stress responses that plants share with other eukaryotes is a global shutdown and reprogramming of protein synthesis. This mechanism prevents unnecessary energy expenditures at the times of stress and ensures that only specific proteins vital for stress recovery are produced, minimizing stress-related damage and promoting cell survival. At the cellular level, this response is associated with the formation in the cytoplasm of the membraneless organelles called “stress granules” (SGs). These organelles are assemblies of untranslating messenger ribonucleoproteins (mRNPs) composed of mRNAs stalled in translation initiation and a diverse repertoire of proteins.
Research on plant SGs is still in its infancy. In plants, the current knowledge of SG composition and function as well as their assembly requirements and regulation through stress-activated signaling pathways remain totally unknown. More importantly, it is unclear how SGs work and to what extent they can affect stress resistance. In this context, this project aims to better understand the fundamental function of SGs in the regulation of plant response to stress using the unicellular green alga Chlamydomonas reinhardtii and Arabidopsis as model organisms. To achieve these general goals, a multidisciplinary approach including cell and molecular biology, genetic, physiological and bioinformatics techniques, were implemented in order to evaluate four major Aims.
