title: Overexpression of pigeonpea stress-induced cold and drought regulatory gene (CcCDR) confers drought, salt, and cold tolerance in Arabidopsis.
abstract: A potent cold and drought regulatory protein-encoding gene (CcCDR) was isolated from the subtractive cDNA library of pigeonpea plants subjected to drought stress. CcCDR was induced by different abiotic stress conditions in pigeonpea. Overexpression of CcCDR in Arabidopsis thaliana imparted enhanced tolerance against major abiotic stresses, namely drought, salinity, and low temperature, as evidenced by increased biomass, root length, and chlorophyll content. Transgenic plants also showed increased levels of antioxidant enzymes, proline, and reducing sugars under stress conditions. Furthermore, CcCDR-transgenic plants showed enhanced relative water content, osmotic potential, and cell membrane stability, as well as hypersensitivity to abscisic acid (ABA) as compared with control plants. Localization studies confirmed that CcCDR could enter the nucleus, as revealed by intense fluorescence, indicating its possible interaction with various nuclear proteins. Microarray analysis revealed that 1780 genes were up-regulated in CcCDR-transgenics compared with wild-type plants. Real-time PCR analysis on selected stress-responsive genes, involved in ABA-dependent and -independent signalling networks, revealed higher expression levels in transgenic plants, suggesting that CcCDR acts upstream of these genes. The overall results demonstrate the explicit role of CcCDR in conferring multiple abiotic stress tolerance at the whole-plant level. The multifunctional CcCDR seems promising as a prime candidate gene for enhancing abiotic stress tolerance in diverse plants.
authors.affiliation: Centre for Plant Molecular Biology, Osmania University, Hyderabad, 500 007, India.
authors.forename: Srinath
authors.initials: S
authors.lastname: Tamirisa
authors.affiliation: Centre for Plant Molecular Biology, Osmania University, Hyderabad, 500 007, India.
authors.forename: Dashavantha Reddy
authors.initials: DR
authors.lastname: Vudem
authors.affiliation: Centre for Plant Molecular Biology, Osmania University, Hyderabad, 500 007, India rao_kv1@rediffmail.com.
authors.forename: Venkateswara Rao
authors.initials: VR
authors.lastname: Khareedu
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D036561:Cajanus / Q000235:genetics*; D003001:Cloning, Molecular; D003080:Cold Temperature; D055864:Droughts; D005786:Gene Expression Regulation; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D055049:Salt Tolerance; D055051:Salt-Tolerant Plants / Q000235:genetics / Q000502:physiology*
chemical_list: D010940:Plant Proteins
keywords: Abiotic stress tolerance; Cajanus cajan; cDNA library; cold and drought regulatory gene; nuclear localization.