title: Pepper CaREL1, a ubiquitin E3 ligase, regulates drought tolerance via the ABA-signalling pathway.
abstract: Drought stress conditions in soil or air hinder plant growth and development. Here, we report that the hot pepper (C apsicum a nnuum) RING type E3 Ligase 1 gene (CaREL1) is essential to the drought stress response. CaREL1 encodes a cytoplasmic- and nuclear-localized protein with E3 ligase activity. CaREL1 expression was induced by abscisic acid (ABA) and drought. CaREL1 contains a C3H2C3-type RING finger motif, which functions in ubiquitination of the target protein. We used CaREL1-silenced pepper plants and CaREL1-overexpressing (OX) transgenic Arabidopsis plants to evaluate the in vivo function of CaREL1 in response to drought stress and ABA treatment. CaREL1-silenced pepper plants displayed a drought-tolerant phenotype characterized by ABA hypersensitivity. In contrast, CaREL1-OX plants exhibited ABA hyposensitivity during the germination, seedling, and adult stages. In addition, plant growth was severely impaired under drought stress conditions, via a high level of transpirational water loss and decreased stomatal closure. Quantitative RT-PCR analyses revealed that ABA-related drought stress responsive genes were more weakly expressed in CaREL1-OX plants than in wild-type plants, indicating that CaREL1 functions in the drought stress response via the ABA-signalling pathway. Taken together, our results indicate that CaREL1 functions as a negative regulator of ABA-mediated drought stress tolerance.
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul, 06974, Republic of Korea.
authors.forename: Chae Woo
authors.initials: CW
authors.lastname: Lim
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul, 06974, Republic of Korea.
authors.forename: Chanmi
authors.initials: C
authors.lastname: Park
authors.affiliation: Department of Physical Education, Chung-Ang University, Seoul, 06974, Republic of Korea.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul, 06974, Republic of Korea.
authors.forename: Hyunhee
authors.initials: H
authors.lastname: Joo
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul, 06974, Republic of Korea.
authors.forename: Eunji
authors.initials: E
authors.lastname: Hong
authors.affiliation: Department of Life Science (BK21 program), Chung-Ang University, Seoul, 06974, Republic of Korea. sclee1972@cau.ac.kr.
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Lee
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D000220:Adaptation, Biological; D000595:Amino Acid Sequence; D002212:Capsicum / Q000145:classification / Q000502:physiology*; D003001:Cloning, Molecular; D055864:Droughts; D020868:Gene Silencing; D010641:Phenotype; D010802:Phylogeny; D030821:Plants, Genetically Modified; D021381:Protein Transport; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D013312:Stress, Physiological; D044767:Ubiquitin-Protein Ligases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000040:Abscisic Acid; D044767:Ubiquitin-Protein Ligases