title: Endoplasmic reticulum- and Golgi-localized phospholipase A2 plays critical roles in Arabidopsis pollen development and germination.
abstract: The phospholipase A(2) (PLA(2)) superfamily of lipolytic enzymes is involved in a number of essential biological processes, such as inflammation, development, host defense, and signal transduction. Despite the proven involvement of plant PLA(2)s in many biological functions, including senescence, wounding, elicitor and stress responses, and pathogen defense, relatively little is known about plant PLA(2)s, and their genes essentially remain uncharacterized. We characterized three of four Arabidopsis thaliana PLA(2) paralogs (PLA(2)-β, -γ, and -δ) and found that they (1) are expressed during pollen development, (2) localize to the endoplasmic reticulum and/or Golgi, and (3) play critical roles in pollen development and germination and tube growth. The suppression of PLA(2) using the RNA interference approach resulted in pollen lethality. The inhibition of pollen germination by pharmacological PLA(2) inhibitors was rescued by a lipid signal molecule, lysophosphatidyl ethanolamine. Based on these results, we propose that plant reproduction, in particular, male gametophyte development, requires the activities of the lipid-modifying PLA(2)s that are conserved in other organisms.
authors.affiliation: School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
authors.forename: Hae Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Sung Han
authors.initials: SH
authors.lastname: Ok
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Bahn
authors.forename: Juno
authors.initials: J
authors.lastname: Jang
authors.forename: Sung Aeong
authors.initials: SA
authors.lastname: Oh
authors.forename: Soon Ki
authors.initials: SK
authors.lastname: Park
authors.forename: David
authors.initials: D
authors.lastname: Twell
authors.forename: Stephen Beungtae
authors.initials: SB
authors.lastname: Ryu
authors.forename: Jeong Sheop
authors.initials: JS
authors.lastname: Shin
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000201:enzymology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018525:Germination; D006056:Golgi Apparatus / Q000201:enzymology; D008246:Lysophospholipids / Q000378:metabolism; D009154:Mutation; D054467:Phospholipases A2 / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D011058:Pollen / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D034622:RNA Interference; D018749:RNA, Plant / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D008246:Lysophospholipids; D018749:RNA, Plant; C008301:lysophosphatidylethanolamine; D054467:Phospholipases A2