title: Rice Rab11 is required for JA-mediated defense signaling.
abstract: Rab proteins play an essential role in regulating vesicular transport in eukaryotic cells. Previously, we characterized OsRab11, which in concert with OsGAP1 and OsGDI3 regulates vesicular trafficking from the trans-Golgi network (TGN) to the plasma membrane or vacuole. To further elucidate the physiological function of OsRab11 in plants, we performed yeast two-hybrid screens using OsRab11 as bait. OsOPR8 was isolated and shown to interact with OsRab11. A co-immunoprecipitation assay confirmed this interaction. The green fluorescent protein-OsOPR8 fusion product was targeted to the cytoplasm and peroxisomes of protoplasts from Arabidopsis thaliana. OsOPR8 exhibited NADPH-dependent reduction activity when 2-cyclohexen-1-one (CyHE) and 12-oxo-phytodienoic acid (OPDA) were supplied as possible substrates. Interestingly, NADPH oxidation by OsOPR8 was increased when wild-type OsRab11 or the constitutively active form of OsRab11 (Q78L) were included in the reaction mix, but not when the dominant negative form of OsRab11 (S28N) was included. OsRab11 was expressed broadly in plants and both OsRab11 and OsOPR8 were induced by jasmonic acid (JA) and elicitor treatments. Overexpressed OsRab11 transgenic plants showed resistance to pathogens through induced expression of JA-responsive genes. In conclusion, OsRab11 may be required for JA-mediated defense signaling by activating the reducing activity of OsOPR8.
authors.affiliation: Department of Molecular Biotechnology, Dong-A University, Busan 604-714, South Korea.
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Hong
authors.forename: Yun mi
authors.initials: Ym
authors.lastname: Lee
authors.forename: Young Sim
authors.initials: YS
authors.lastname: Son
authors.forename: Chak Han
authors.initials: CH
authors.lastname: Im
authors.forename: Young Byung
authors.initials: YB
authors.lastname: Yi
authors.forename: Yeong Gil
authors.initials: YG
authors.lastname: Rim
authors.forename: Jeong Dong
authors.initials: JD
authors.lastname: Bahk
authors.forename: Jae Bok
authors.initials: JB
authors.lastname: Heo
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D003517:Cyclopentanes / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism; D060467:Disease Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D054883:Oxylipins / Q000494:pharmacology; D020675:Peroxisomes / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D011523:Protoplasts / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D044224:Pseudomonas syringae / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics*; D020798:Two-Hybrid System Techniques; D020691:rab GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D000099193:rab11 GTP-Binding Proteins
chemical_list: D003517:Cyclopentanes; D049452:Green Fluorescent Proteins; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C011006:jasmonic acid