Identification of a highly drought-resistantpp7l hda6mutant

Abstract

AbstractPlants have evolved efficient strategies to cope with drought stress, including stomata closure, significant changes in nuclear gene expression, and epigenetic mechanisms. Previously, we identifiedArabidopsis thalianaPROTEIN PHOSPHATASE7-LIKE (PP7L) as an extrachloroplastic protein that promotes chloroplast development and high light, and salt tolerance. Here, we demonstrate that thepp7lmutant can withstand prolonged periods of drought stress. Interestingly, chloroplast development inpp7lrecovers under drought conditions, despite growth of the mutant is impaired under normal growth conditions. To assess the (post)transcriptional changes occurring in thepp7lmutant under different durations of drought exposure, we used long non-coding RNA-sequencing. Compared to the previously reported drought-responsive changes in the wild type, the drought-responsive changes detected in thepp7lmutant were negligible. Our analysis of data generated in this study and previously motivated us to create app7l hda6mutant, which exhibits remarkable drought resistance. Notably, the growth penalty associated withpp7lwas alleviated in the double mutant, ruling out a dwarf effect on the drought-tolerant trait of this genotype.