title: Identification and functional roles of CaDIN1 in abscisic acid signaling and drought sensitivity.
abstract: Plants frequently face challenges caused by various abiotic stresses, including drought, and have evolved defense mechanisms to counteract the deleterious effects of these stresses. The phytohormone abscisic acid (ABA) is involved in signal transduction pathways that mediate defense responses of plants to abiotic stress. Here, we report a new function of the CaDIN1 protein in defense responses to abiotic stress. The CaDIN1 gene was strongly induced in pepper leaves exposed to ABA, NaCl, and drought stresses. CaDIN1 proteins share high sequence homology with other known DIN1 proteins and are localized in chloroplasts. We generated CaDIN1-silenced peppers and overexpressing transgenic Arabidopsis plants and evaluated their response to ABA and drought stress. Virus-induced gene silencing of CaDIN1 in pepper plants conferred enhanced tolerance to drought stress, which was accompanied by low levels of lipid peroxidation in dehydrated leaves. CaDIN1-overexpressing transgenic plants exhibited reduced sensitivity to ABA during seed germination and seedling stages. Transgenic plants were more vulnerable to drought than that by the wild-type plants because of decreased expression of ABA responsive stress-related genes and reduced stomatal closure in response to ABA. Together, these results suggest that CaDIN1 modulates drought sensitivity through ABA-mediated cell signaling.
authors.affiliation: Department of Life Science (BK21 Program), Chung-Ang University, Seoul, 156-756, Republic of Korea.
authors.forename: Sohee
authors.initials: S
authors.lastname: Lim
authors.forename: Woonhee
authors.initials: W
authors.lastname: Baek
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Lee
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D000222:Adaptation, Physiological / Q000235:genetics; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D002212:Capsicum / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D014026:Nicotiana / Q000166:cytology / Q000235:genetics / Q000378:metabolism
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D049452:Green Fluorescent Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid