Remodelling of cytoskeleton and plasma membrane proteins contributes to drought sensitivity of Arabidopsisrhd2mutant

Abstract

AbstractNADPH oxidases are enzymes localised in the plasma membrane and emitting superoxide to the extracellular space. By production of superoxide as one type of reactive oxygen species (ROS), they exert pleiotropic functions in plant development and various stress responses.Arabidopsis thalianaRESPIRATORY BURST OXIDASE HOMOLOG PROTEIN C/ROOT HAIR DEFECTIVE 2 (AtRBOHC/RHD2) is an NADPH oxidase with preferential gene expression in roots. Polar localisation and ROS production by this enzyme are essential for root hair elongation. However, the proteome-wide and physiological consequences ofRBOHC/RHD2mutations are unknown. To find out potential new functions of AtRBOHC/RHD2, we employed a differential proteomic analysis of Arabidopsisrhd2-1mutant, carrying a loss-of-function mutation inRBOHC/RHD2. Proteomic analyses that were validated with independent biochemical, phenotypical and advanced microscopy methods, showed quantitative deregulation of proteins involved in abiotic and biotic stress response, metabolism, vesicular transport and cell wall modification. Considerable differences in the differential proteomes between roots and above-ground parts were found in the mutant. The altered abundance of aquaporins and homeostasis of transmembrane pumps and transporters most likely determine the higher sensitivity of Arabidopsisrhd2-1mutant to drought.HighlightProteomics and advanced microscopy reveal that the drought sensitivity of Arabidopsis mutant inROOT HAIR DEFECTIVE 2is linked to altered homeostasis of plasma membrane proteins and cytoskeleton remodelling.