Crosstalk between stress, energy signalling and the chloroplast

Given their sessile nature, plants are frequently exposed to a wide range of abiotic stresses, negatively impacting plant growth and agricultural yields worldwide. This is aggravated by the increased frequency, duration and intensity of stressful environmental events due to global climate change. Thus, understanding plant responses to stress is essential to guarantee the development of novel plant varieties and agronomic practices that can better safeguard our food security.

Chloroplasts are the organelles in plant cells responsible for photosynthesis. Many abiotic stresses have a strong effect on the chloroplast proteome, with photosynthetic proteins being particularly sensitive. Remodelling of the chloroplast proteome in response to stress reduces photosynthetic capacity, possibly as a strategy to prevent further oxidative damage.

However, despite the severe detrimental effect on chloroplast function, not much is known about the molecular players and pathways involved in these stress responses.

In this project, we will investigate how the SUCROSE NON-FERMENTING1 (SNF1)-RELATED KINASE1 (SnRK1) impacts on chloroplast biogenesis and maintenance. SnRK1 is a central player in plant stress responses and metabolic homeostasis, and several independent observations indicate that this protein kinase targets the chloroplast as part of the stress response.

Specific objectives will focus on (i) assessing how chloroplast function is affected by genetic disruption of SnRK1; (ii) validating protein-protein interactions between this kinase and established components of the chloroplast protein import machinery; and (iii) assessing the physiological relevance of the newly identified molecular links between SnRK1 and the chloroplast.