title: Quantitative proteomics-based analysis supports a significant role of GTG proteins in regulation of ABA response in Arabidopsis roots.
abstract: Abscisic acid (ABA) is proposed to be perceived by multiple receptors in plants. We have previously reported on the role of two GPCR-type G-proteins (GTG proteins) as plasma membrane-localized ABA receptors in Arabidopsis thaliana. However, due to the presence of multiple transmembrane domains, detailed structural and biochemical characterization of GTG proteins remains limited. Since ABA induces substantial changes in the proteome of plants, a labeling LC-based quantitative proteomics approach was applied to elucidate the global effects and possible downstream targets of GTG1/GTG2 proteins. Quantitative differences in protein abundance between wild-type and gtg1gtg2 were analyzed for evaluation of the effect of ABA on the root proteome and its dependence on the presence of functional GTG1/GTG2 proteins. The results presented in this study reveal the most comprehensive ABA-responsive root proteome reported to date in Arabidopsis. Notably, the majority of ABA-responsive proteins required the presence of GTG proteins, supporting their key role in ABA signaling. These observations were further confirmed by additional experiments. Overall, comparison of the ABA-dependent protein abundance changes in wild-type versus gtg1gtg2 provides clues to their possible links with some of the well-established effectors of the ABA signaling pathways and their role in mediating phytohormone cross-talk.
authors: Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, Missouri 63132, United States.
authors: Sophie
authors: S
authors: Alvarez
authors: Swarup
authors: S
authors: Roy Choudhury
authors: Leslie M
authors: LM
authors: Hicks
authors: Sona
authors: S
authors: Pandey
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism / Q000502:physiology*; D015153:Blotting, Western; D002853:Chromatography, Liquid; D018517:Plant Roots / Q000378:metabolism / Q000502:physiology*; D040901:Proteomics; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D053719:Tandem Mass Spectrometry
chemical_list: D029681:Arabidopsis Proteins; D000040:Abscisic Acid