title: Phospholipase A2beta mediates light-induced stomatal opening in Arabidopsis.
abstract: Phospholipase A(2) (PLA(2)) catalyses the hydrolysis of phospholipids into lysophospholipids and free fatty acids. Physiological studies have indicated that PLA(2) is involved in stomatal movement. However, genetic evidence of a role of PLA(2) in guard cell signalling has not yet been reported. To identify PLA(2) gene(s) that is (are) involved in light-induced stomatal opening, stomatal movement was examined in Arabidopsis thaliana plants in which the expression of PLA(2) isoforms was reduced or knocked-out. Light-induced stomatal opening in PLA(2)alpha knockout plants did not differ from wild-type plants. Plants in which PLA(2)beta was silenced by RNA interference exhibited delayed light-induced stomatal opening, and this phenotype was reversed by exogenous lysophospholipids, which are products of PLA(2). Stomatal opening in transgenic plants that over-expressed PLA(2)beta was faster than wild-type plants. The expression of PLA(2)beta was localized to the endoplasmic reticulum of guard cells, and increased in response to light in the mature leaf. Aristolochic acid, which inhibits light-induced stomatal opening, inhibited the activity of purified PLA(2)beta. Collectively, these results provide evidence that PLA(2)beta is involved in light-induced stomatal opening in Arabidopsis.
authors: Division of Molecular and Life Sciences, POSTECH, Pohang 790-784, Korea.
authors: Jiyoung
authors: J
authors: Seo
authors: Hyoung Yool
authors: HY
authors: Lee
authors: Hyunju
authors: H
authors: Choi
authors: Yunjung
authors: Y
authors: Choi
authors: Yuree
authors: Y
authors: Lee
authors: Yong-Woo
authors: YW
authors: Kim
authors: Stephen Beungtae
authors: SB
authors: Ryu
authors: Youngsook
authors: Y
authors: Lee
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034341:Aristolochic Acids / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000235:genetics / Q000528:radiation effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D054513:Group IV Phospholipases A2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008027:Light; D054046:Plant Stomata / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects*; D021381:Protein Transport; D034622:RNA Interference
chemical_list: D029681:Arabidopsis Proteins; D034341:Aristolochic Acids; D004791:Enzyme Inhibitors; C000228:aristolochic acid I; D054513:Group IV Phospholipases A2