title: Cotton cytochrome P450 CYP82D regulates systemic cell death by modulating the octadecanoid pathway.
abstract: Plant oxylipins are derived from unsaturated fatty acids and play roles in plant growth and development as well as defence. Although recent studies have revealed that fatty acid metabolism is involved in systemic acquired resistance, the precise function of oxylipins in plant defence remains unknown. Here we report a cotton P450 gene SILENCE-INDUCED STEM NECROSIS (SSN), RNAi suppression of which causes a lesion mimic phenotype. SSN is also involved in jasmonate metabolism and the response to wounding. Fatty acid and oxylipin metabolite analysis showed that SSN overexpression causes hyperaccumulation of hydroxide and ketodiene fatty acids and reduced levels of 18:2 fatty acids, whereas silencing causes an imbalance in LOX (lipoxygenase) expression and excessive hydroperoxide fatty acid accumulation. We also show that an unknown oxylipin-derived factor is a putative mobile signal required for systemic cell death and hypothesize that SSN acts as a valve to regulate HR on pathogen infection.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Longqing
authors.initials: L
authors.lastname: Sun
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Longfu
authors.initials: L
authors.lastname: Zhu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Daojun
authors.initials: D
authors.lastname: Yuan
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Min
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: Xianlong
authors.initials: X
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D016923:Cell Death; D003517:Cyclopentanes / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D003368:Gossypium / Q000235:genetics / Q000378:metabolism*; D008084:Lipoxygenase / Q000378:metabolism; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000378:metabolism; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism
chemical_list: D003517:Cyclopentanes; D005227:Fatty Acids; D054883:Oxylipins; D010940:Plant Proteins; C011006:jasmonic acid; D003577:Cytochrome P-450 Enzyme System; D008084:Lipoxygenase; D020156:Salicylic Acid