title: Abscisic acid receptor PYRABACTIN RESISTANCE-LIKE 8, PYL8, is involved in glucose response and dark-induced leaf senescence in Arabidopsis.
abstract: Abscisic acid (ABA) receptors in plants are thought to be involved in various cellular processes mediated by signal transduction pathways. There are about 14 ABA receptors in Arabidopsis, but only a few have been studied. In this study, we investigated the effect of the disruption and overexpression of an ABA receptor gene, PYL8 (At5g53160) on plant responses to glucose (Glc) and dark-induced leaf senescence. Expression of PYL8 was strongly reduced by Glc treatment. Overexpression of PYL8 in Arabidopsis resulted in significantly reduced seed germination and cotyledon greening under high Glc conditions, while RNAi transgenic lines were more insensitive to Glc stress. Activities of two Glc-responsive genes, Arabidopsis thaliana Hexokinase 1 (AtHXK1) and ABA insensitive 5 (ABI5) were higher in PYL8-overexpressing plants than in the wild-type (WT) plants after Glc treatment, whereas the transcript levels of these genes in RNAi plants decreased. Furthermore, PYL8-overexpressing plants displayed increased yellowing, membrane ion leakage, and reduced chlorophyll content due to dark-induced senescence, and exhibited stronger expression of a group of senescence-inducible genes than did WT. The data show that PYL8 plays essential roles in responses to both Glc and dark-induced senescence in A. thaliana.
authors.affiliation: Department of Plant Biotechnology, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Ha-Nul
authors.initials: HN
authors.lastname: Lee
authors.affiliation: Department of Rural and Biosystems Engineering, Agricultural Robotics and Automation Research Center, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Kyeong-Hwan
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Plant Biotechnology, Chonnam National University, Gwangju 500-757, Republic of Korea. Electronic address: cskim626@chonnam.ac.kr.
authors.forename: Cheol Soo
authors.initials: CS
authors.lastname: Kim
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics; D003624:Darkness; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005947:Glucose / Q000378:metabolism*; D006593:Hexokinase / Q000235:genetics; D009281:Naphthalenes / Q000633:toxicity; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism / Q000528:radiation effects; D030821:Plants, Genetically Modified; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D013449:Sulfonamides / Q000633:toxicity
chemical_list: C409743:ABI5 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D009281:Naphthalenes; C582322:PYL8 protein, Arabidopsis; D010937:Plant Growth Regulators; D012333:RNA, Messenger; D018749:RNA, Plant; D013449:Sulfonamides; C540973:pyrabactin; D000040:Abscisic Acid; D006593:Hexokinase; C473630:ATHXK1 protein, Arabidopsis; D005947:Glucose
keywords: ABA receptor; ABI5; Glucose sensitivity; PYL8; Senescence