title: Expression of CAP2, an APETALA2-family transcription factor from chickpea, enhances growth and tolerance to dehydration and salt stress in transgenic tobacco.
abstract: The APETALA2 (AP2) domain defines a large family of DNA-binding proteins that play important roles in plant morphology, development, and stress response. We describe isolation and characterization of a gene (CAP2) from chickpea (Cicer arietinum) encoding a novel AP2-family transcription factor. Recombinant CAP2 protein bound specifically to C-repeat/dehydration-responsive element in gel-shift assay and transactivated reporter genes in yeast (Saccharomyces cerevisiae) one-hybrid assay. CAP2 appeared to be a single/low copy intronless gene, and the protein product localized in the nucleus. Transcript level of CAP2 increased by dehydration and by treatment with sodium chloride, abscisic acid, and auxin, but not by treatment with low temperature, salicylic acid, and jasmonic acid. The 35S promoter-driven expression of CAP2 in tobacco (Nicotiana tabacum) caused drastic increase in the leaf cell size, and, thereby, in leaf surface area and number of lateral roots. Transgenic plants demonstrated more tolerance to dehydration and salt stress than the wild-type plants. Transgenic plants expressed higher steady-state transcript levels of abiotic stress-response genes NtERD10B and NtERD10C and auxin-response genes IAA4.2 and IAA2.5. Taken together, our results indicated a mutual interrelation between plant growth-development and abiotic stress-response pathways and a probable involvement of CAP2 in both the signaling pathways.
authors.affiliation: National Centre for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Shukla
authors.forename: Sumita
authors.initials: S
authors.lastname: Raha
authors.forename: Vineeta
authors.initials: V
authors.lastname: Tripathi
authors.forename: Debasis
authors.initials: D
authors.lastname: Chattopadhyay
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D029863:Cicer / Q000235:genetics / Q000502:physiology*; D003681:Dehydration / Q000378:metabolism; D018628:Gene Dosage; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000502:physiology*; D014170:Transformation, Genetic
chemical_list: D012965:Sodium Chloride