Cotton cytochrome P450 CYP82D regulates systemic cell death by modulating the octadecanoid pathway

• Published in: Nature communications 2014-11, Vol.5 (1), p.5372-5372, Article 5372
• Main Authors: Sun, Longqing, Zhu, Longfu, Xu, Li, Yuan, Daojun, Min, Ling, Zhang, Xianlong
• Format: Article
• Language: English
• Subjects: 13/106; 13/2; 13/89; 13/95; 14/19; 14/28; 38/1; 38/39; 631/443/319; 631/449/1659; 631/80/82; 82/16; 82/58; Base Sequence; Cell Death; Cyclopentanes - metabolism; Cytochrome P-450 Enzyme System - genetics; Cytochrome P-450 Enzyme System - metabolism; Fatty Acids - metabolism; Gossypium - genetics; Gossypium - metabolism; Humanities and Social Sciences; Lipoxygenase - metabolism; Molecular Sequence Data; multidisciplinary; Oxylipins - metabolism; Phenotype; Plant Proteins - genetics; Plant Proteins - metabolism; Salicylic Acid - metabolism; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms6372

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. Oxylipin signalling is known to play important roles in plant growth, development and defence against pathogens. Here Sun et al. identify a novel cytochrome P450 in cotton and show that its suppression leads to activation of plant defence responses and alteration of oxylipin metabolism.