Loss function of SL (sekiguchi lesion) in the rice cultivar Minghui 86 leads to enhanced resistance to (hemi)biotrophic pathogens

BMC Plant Biology

Gang Li¹  Yan Lin¹  Dagang Tian¹  Feng Wang¹  Zaijie Chen¹  Yuqing Niu²  Qiong Luo³  Fang Yang⁴  Mo Wang⁵ 

[1] Biotechnology Research Institute, Fujian Key Laboratory of Genetic Engineering for Agriculture, Fujian Academy of Agricultural Sciences, 350003, Fuzhou, Fujian, China;Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, 350002, Fuzhou, Fujian, China;Ministry of Education Key Laboratory of Agriculture Biodiversity for Plant Disease Management, Yunnan Agricultural University, 650201, Kunming, China;State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, 350002, Fuzhou, Fujian, China;State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, 350002, Fuzhou, Fujian, China;Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, 350002, Fuzhou, Fujian, China;Fujian University Key Laboratory for Plant–Microbe Interaction, Fujian Agriculture and Forestry University, 350002, Fuzhou, Fujian, China;

关键词: Rice;    Serotonin;    Reactive oxygen species;    PAMP-triggered immunity;    Defense hormones;    Pyricularia oryzae;   

DOI  :  10.1186/s12870-020-02724-6

来源: Springer

【 摘 要 】

BackgroundSerotonin, originally identified as a neurotransmitter in mammals, functions as an antioxidant to scavenge cellular ROS in plants. In rice, the conversion of tryptamine to serotonin is catalyzed by SL (sekiguchi lesion), a member of cytochrome P450 monooxygenase family. The sl mutant, originated from rice cultivar Sekiguchi-asahi, exhibits spontaneous lesions, whereas its immune responses to pathogens have not been clearly characterized.ResultsHere we identified three allelic mutants of SL in an indica rice restore line Minghui 86 (MH86), named as sl-MH-1, − 2 and − 3, all of which present the typical lesions under normal growth condition. Compared with those in MH86, the serotonin content in sl-MH-1 is dramatically decreased, whereas the levels of tryptamine and L-trytophan are significantly increased. The sl-MH-1 mutant accumulates high H2O2 level at its lesion sites and is more sensitive to exogenous H2O2 treatment than the wild type. When treated with the reductant vitamin C (Vc), the lesion formation on sl-MH-1 leaves could be efficiently suppressed. In addition, sl-MH-1 displayed more resistant to both the blast fungus and blight bacteria, Pyricularia oryzae (P. oryzae, teleomorph: Magnaporthe oryzae) and Xanthomonas oryzae pv. Oryzae (Xoo), respectively. The pathogen-associated molecular patterns (PAMPs)-triggered immunity (PTI) responses, like reactive oxygen species (ROS) burst and callose deposition, were enhanced in sl-MH-1. Moreover, loss function of SL resulted in higher resting levels of the defense hormones, salicylic acid and jasmonic acid. The RNA-seq analysis indicated that after P. oryzae infection, transcription of the genes involved in reduction-oxidation regulation was the most markedly changed in sl-MH-1, compared with MH86.ConclusionsOur results indicate that SL, involving in the final step of serotonin biosynthesis, negatively regulates rice resistance against (hemi)biotrophic pathogens via compromising the PTI responses and defense hormones accumulation.

【 授权许可】

CC BY