The role of phospholipase C in plant drought tolerance

Drought is one of the most impactful stresses impacting global food yields. The overexpression (OE) of Phospholipase C (PLC) results in drought tolerant plants in various plant species, both monocots and dicots. In this thesis we give an overview of the existing knowledge of PLCs, and especially it’s role in drought stress. We OE the Arabidopsis PLC2, -7, and -9, in addition to the already published OEs of PLC3, -4, -5, and -7. All of these lines have higher survivability when exposed to prolonged water deprivation. The lines were studied using phenomics, transcriptomics and metabolomics to better understand what process causes the drought tolerance. No differences in size or biomass were found, but an increase in compactness during drought stress was observed. RNA-seq revealed potential roles for the auxin, brassinosteroids, circadian rhythm, photosynthesis, aquaporin, and ROS pathways. The metabolome revealed that drought responsive metabolites were lower in concentration during drought, but also control conditions. And that phosphate levels were drastically reduced in both control and drought conditions. We pose several potential ways in which OE of PLC might lead to the found drought tolerance.