A Microsomal Proteomics View of H(2)O(2)- and ABA-Dependent Responses

The plant hormone abscisic acid (ABA) modulates a number of plant developmental processes and responses to stress. In planta, ABA has been shown to induce reactive oxygen species (ROS) production through the action of plasma membrane-associated nicotinamide adenine dinucleotide phosphate (NADPH)-oxidases. Although quantitative proteomics studies have been performed to identify ABA- or hydrogen peroxide (H(2)O(2))-dependent proteins, little is known about the ABA- and H(2)O(2)-dependent microsomal proteome changes. Here, we examined the effect of 50 µM of either H(2)O(2) or ABA on the Arabidopsis microsomal proteome using tandem mass spectrometry and identified 86 specifically H(2)O(2)-dependent, and 52 specifically ABA-dependent proteins that are differentially expressed. We observed differential accumulation of proteins involved in the tricarboxylic acid (TCA) cycle notably in response to H(2)O(2). Of these, aconitase 3 responded to both H(2)O(2) and ABA. Additionally, over 30 proteins linked to RNA biology responded significantly to both treatments. Gene ontology categories such as ‘response to stress’ and ‘transport’ were enriched, suggesting that H(2)O(2) or ABA directly and/or indirectly cause complex and partly overlapping cellular responses. Data are available via ProteomeXchange with identifier PXD006513.