AtPLAI is an acyl hydrolase involved in basal jasmonic acid production and Arabidopsis resistance to Botrytis cinerea.
Intracellular phospholipase A2 (PLA2) plays an important role in regulating oxylipin biosynthesis in mammals, but the molecular and biochemical nature of intracellular PLA2 is not well understood in plants. Arabidopsis thaliana gene At1g61850 (AtPLAI) encodes a 140-kDa protein that is most similar to mammalian calcium-independent PLA2, and additionally contains leucine-rich repeats and Armadillo repeats. AtPLAI hydrolyzes phospholipids at both the sn-1 and sn-2 positions, but prefers galactolipids to phospholipids as substrates. Profiling of lipid species altered in response to the necrotrophic fungus Botrytis cinerea revealed decreases in the levels of phosphatidylglycerol and digalactosyldiacylglycerol, suggesting that hydrolysis of plastidic polar lipids might provide precursors for pathogen-induced jasmonic acid (JA) production. Disruption of AtPLAI by T-DNA insertion reduced the basal level of JA, but did not impede pathogen-induced production of JA, free linolenic acid, or hydrolysis of plastidic lipids. Still, AtPLAI-deficient plants exhibited more damage than wild type plants after B. cinerea infection, and pretreatment of plants with methyl jasmonate alleviated pathogen damage to the mutant plants. The study shows that AtPLAI is an acyl hydrolase, rather than a specific phospholipase A. AtPLAI is involved in basal JA production and Arabidopsis resistance to the necrotrophic fungus B. cinerea.
Yang
Wenyu
W
Department of Biology, University of Missouri, St. Louis, Missouri 63121; Donald Danforth Plant Science Center, St. Louis, Missouri 63132.
Devaiah
Shivakumar P
SP
Department of Biology, University of Missouri, St. Louis, Missouri 63121; Donald Danforth Plant Science Center, St. Louis, Missouri 63132.
Pan
Xiangqing
X
Department of Biology, University of Missouri, St. Louis, Missouri 63121; Donald Danforth Plant Science Center, St. Louis, Missouri 63132.
Isaac
Giorgis
G
Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, Kansas 66506.
Welti
Ruth
R
Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, Kansas 66506.
Wang
Xuemin
X
Department of Biology, University of Missouri, St. Louis, Missouri 63121; Donald Danforth Plant Science Center, St. Louis, Missouri 63132. Electronic address: wangxue@umsl.edu.
D017360:Arabidopsis / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D020171:Botrytis / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry* / Q000502:physiology*; D003517:Cyclopentanes / Q000378:metabolism*; D038983:Galactolipids / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D008055:Lipids / Q000737:chemistry; D008957:Models, Genetic; D009154:Mutation; D054883:Oxylipins; D010741:Phospholipases A / Q000378:metabolism / Q000502:physiology*; D054467:Phospholipases A2; D010743:Phospholipids / Q000378:metabolism; D010802:Phylogeny; D020156:Salicylic Acid / Q000378:metabolism; D013997:Time Factors
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D038983:Galactolipids; D008055:Lipids; D054883:Oxylipins; D010743:Phospholipids; C011006:jasmonic acid; D002265:Carboxylic Ester Hydrolases; C522182:PLAI protein, Arabidopsis; D010741:Phospholipases A; D054467:Phospholipases A2; D020156:Salicylic Acid