title: Oil body-mediated defense against fungi: From tissues to ecology.
abstract: Oil bodies are localized in the seed cells and leaf cells of many land plants. They have a passive function as storage organelles for lipids. We recently reported that the leaf oil body has an active function as a subcellular factory that produces an antifungal oxylipin during fungal infection in Arabidopsis thaliana. Here, we propose a model for oil body-mediated plant defense. Remarkably, senescent leaves develop oil bodies and accumulate α-dioxygenase1 (α-DOX1) and caleosin3 (CLO3) on the oil-body membrane, which catalyze the conversion of α-linolenic acid to the phytoalexin 2-hydroxy-octadecatrienoic acid (2-HOT). The model proposes that senescent leaves actively produce antifungal oxylipins and phytoalexins, and abscised leaves contain a mixture of antifungal compounds. In natural settings, the abscised leaves with antifungal compounds accumulate in leaf litter and function to protect healthy tissues and young plants from fungal infection. Plants might have evolved this ecological function for dead leaves.
authors.affiliation: a Graduate School of Science, Kyoto University ; Kyoto , Japan.
authors.forename: Takashi L
authors.initials: TL
authors.lastname: Shimada
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Takano
authors.forename: Ikuko
authors.initials: I
authors.lastname: Hara-Nishimura
mesh_terms: D017360:Arabidopsis / Q000276:immunology* / Q000382:microbiology*; D020231:Colletotrichum / Q000502:physiology*; D066292:Lipid Droplets / Q000378:metabolism*; D008954:Models, Biological; D009928:Organ Specificity; D018515:Plant Leaves / Q000378:metabolism
keywords: 2-HOT, 2-hydroxy-octadecatrienoic acid; CLO3, caleosin3; GPAT2, glycerol-3-phosphate acyltransferase 2, LOX, lipoxygenase; HPOT, hydroperoxyoctadecatrienoic acid; LTP3, lipid transfer protein 3; abscised leaf; caleosin; fungal infection; oil body; oxylipin; phytoalexin; senescence; α-DOX1, α-dioxygenase1; α-dioxygenase