Thiol-based redox proteins in abscisic acid and methyl jasmonate signaling in Brassica napus guard cells.
Reversibly oxidized cysteine sulfhydryl groups serve as redox sensors or targets of redox sensing that are important in various physiological processes. However, little is known about redox-sensitive proteins in guard cells and how they function in stomatal signaling. In this study, Brassica napus guard-cell proteins altered by redox in response to abscisic acid (ABA) or methyl jasmonate (MeJA) were identified by complementary proteomics approaches, saturation differential in-gel electrophoresis and isotope-coded affinity tagging. In total, 65 and 118 potential redox-responsive proteins were identified in ABA- and MeJA-treated guard cells, respectively. All the proteins contain at least one cysteine, and over half of them are predicted to form intra-molecular disulfide bonds. Most of the proteins fall into the functional groups of 'energy', 'stress and defense' and 'metabolism'. Based on the peptide sequences identified by mass spectrometry, 30 proteins were common to ABA- and MeJA-treated samples. A total of 44 cysteines were mapped in the identified proteins, and their levels of redox sensitivity were quantified. Two of the proteins, a sucrose non-fermenting 1-related protein kinase and an isopropylmalate dehydrogenase, were confirmed to be redox-regulated and involved in stomatal movement. This study creates an inventory of potential redox switches, and highlights a protein redox regulatory mechanism in ABA and MeJA signal transduction in guard cells.
['Zhu|Mengmeng|M|', 'Zhu|Ning|N|', 'Song|Wen-yuan|WY|', 'Harmon|Alice C|AC|', 'Assmann|Sarah M|SM|', 'Chen|Sixue|S|']
D000040:Abscisic Acid D000085:Acetates D000595:Amino Acid Sequence D029688:Brassica napus D003517:Cyclopentanes D008969:Molecular Sequence Data D010084:Oxidation-Reduction D054883:Oxylipins D059828:Plant Cells D010940:Plant Proteins D054046:Plant Stomata D040901:Proteomics D015398:Signal Transduction D013438:Sulfhydryl Compounds
redox proteins abscisic acid methyl jasmonate Brassica napus guard cell stomata