title: Overexpression of CaDSR6 increases tolerance to drought and salt stresses in transgenic Arabidopsis plants.
abstract: The partial CaDSR6 (Capsicum annuum Drought Stress Responsive 6) cDNA was previously identified as a drought-induced gene in hot pepper root tissues. However, the cellular role of CaDSR6 with regard to drought stress tolerance was unknown. In this report, full-length CaDSR6 cDNA was isolated. The deduced CaDSR6 protein was composed of 234 amino acids and contained an approximately 30 amino acid-long Asp-rich domain in its central region. This Asp-rich domain was highly conserved in all plant DSR6 homologs identified and shared a sequence identity with the N-terminal regions of yeast p23(fyp) and human hTCTP, which contain Rab protein binding sites. Transgenic Arabidopsis plants overexpressing CaDSR6 (35S:CaDSR6-sGFP) were tolerant to high salinity, as identified by more vigorous root growth and higher levels of total chlorophyll than wild type plants. CaDSR6-overexpressors were also more tolerant to drought stress compared to wild type plants. The 35S:CaDSR6-sGFP leaves retained their water content and chlorophyll more efficiently than wild type leaves in response to dehydration stress. The expression of drought-induced marker genes, such as RD20, RD22, RD26, RD29A, RD29B, RAB18, KIN2, ABF3, and ABI5, was markedly increased in CaDSR6-overexpressing plants relative to wild type plants under both normal and drought conditions. These results suggest that overexpression of CaDSR6 is associated with increased levels of stress-induced genes, which, in turn, conferred a drought tolerant phenotype in transgenic Arabidopsis plants. Overall, our data suggest that CaDSR6 plays a positive role in the response to drought and salt stresses.
authors.affiliation: Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Eun Yu
authors.initials: EY
authors.lastname: Kim
authors.affiliation: National Resources Research Institute, Korea Ginseng Corp., Daejeon 305-805, Republic of Korea.
authors.forename: Young Sam
authors.initials: YS
authors.lastname: Seo
authors.affiliation: Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Ki Youl
authors.initials: KY
authors.lastname: Park
authors.affiliation: Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea.
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea. Electronic address: wtkim@yonsei.ac.kr.
authors.forename: Woo Taek
authors.initials: WT
authors.lastname: Kim
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics; D018525:Germination / Q000235:genetics; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics*; D054712:Salinity; D012965:Sodium Chloride / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D012965:Sodium Chloride
keywords: Arabidopsis thaliana; Asp-rich domain; CaDSR6-overexpressing transgenic plants; Drought and salt stress tolerance; Hot pepper