title: Physiology and proteomics of the water-deficit stress response in three contrasting peanut genotypes.
abstract: Peanut genotypes from the US mini-core collection were analysed for changes in leaf proteins during reproductive stage growth under water-deficit stress. One- and two-dimensional gel electrophoresis (1- and 2-DGE) was performed on soluble protein extracts of selected tolerant and susceptible genotypes. A total of 102 protein bands/spots were analysed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and by quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) analysis. Forty-nine non-redundant proteins were identified, implicating a variety of stress response mechanisms in peanut. Lipoxygenase and 1l-myo-inositol-1-phosphate synthase, which aid in inter- and intracellular stress signalling, were more abundant in tolerant genotypes under water-deficit stress. Acetyl-CoA carboxylase, a key enzyme of lipid biosynthesis, increased in relative abundance along with a corresponding increase in epicuticular wax content in the tolerant genotype, suggesting an additional mechanism for water conservation and stress tolerance. Additionally, there was a marked decrease in the abundance of several photosynthetic proteins in the tolerant genotype, along with a concomitant decrease in net photosynthesis in response to water-deficit stress. Differential regulation of leaf proteins involved in a variety of cellular functions (e.g. cell wall strengthening, signal transduction, energy metabolism, cellular detoxification and gene regulation) indicates that these molecules could affect the molecular mechanism of water-deficit stress tolerance in peanut.
authors.affiliation: Department ofPlant and Soil Science, Texas Tech University, Lubbock, TX, USA.
authors.forename: Kameswara Rao
authors.initials: KR
authors.lastname: Kottapalli
authors.forename: Randeep
authors.initials: R
authors.lastname: Rakwal
authors.forename: Junko
authors.initials: J
authors.lastname: Shibato
authors.forename: Gloria
authors.initials: G
authors.lastname: Burow
authors.forename: David
authors.initials: D
authors.lastname: Tissue
authors.forename: John
authors.initials: J
authors.lastname: Burke
authors.forename: Naveen
authors.initials: N
authors.lastname: Puppala
authors.forename: Mark
authors.initials: M
authors.lastname: Burow
authors.forename: Paxton
authors.initials: P
authors.lastname: Payton
mesh_terms: D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D010367:Arachis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002734:Chlorophyll / Q000032:analysis; D003681:Dehydration; D015180:Electrophoresis, Gel, Two-Dimensional; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D007296:Myo-Inositol-1-Phosphate Synthase / Q000378:metabolism; D010788:Photosynthesis; D010940:Plant Proteins / Q000378:metabolism; D018526:Plant Transpiration; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D018749:RNA, Plant / Q000235:genetics; D013312:Stress, Physiological; D053719:Tandem Mass Spectrometry; D014867:Water / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D020543:Proteome; D018749:RNA, Plant; D014867:Water; D002734:Chlorophyll; D007296:Myo-Inositol-1-Phosphate Synthase; D000103:Acetyl-CoA Carboxylase