A pair of light signaling factors FHY3 and FAR1 regulates plant immunity by modulating chlorophyll biosynthesis

• Published in: Journal of integrative plant biology Vol. 58; no. 1; pp. 91 - 103
• Main Authors: Wang, Wanqing, Tang, Weijiang, Ma, Tingting, Niu, De, Jin, Jing Bo, Wang, Haiyang, Lin, Rongcheng
• Format: Journal Article
• Language: English
• Published: China (Republic : 1949- ) Blackwell Pub 01.01.2016; Blackwell Publishing Ltd; Key Laboratory of Photobiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China%Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China%Biotechnology Research Institute, the Chinese Academy of Agricultural Sciences, Beijing 100081, China%Key Laboratory of Photobiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China; National Center for Plant Gene Research, Beijing 100093, China; John Wiley and Sons Inc
• Subjects: 5-氨基乙酰丙酸; aminolevulinic acid; Arabidopsis; Arabidopsis - genetics; Arabidopsis - immunology; Arabidopsis - metabolism; Arabidopsis - radiation effects; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; biochemical pathways; biosynthesis; Cell Death - radiation effects; chlorophyll; Chlorophyll - biosynthesis; chloroplasts; Disease Resistance - immunology; FAR1; FHY3; Gene Expression Regulation, Plant - radiation effects; gene overexpression; genes; Genes, Plant; hypocotyls; immune response; Light Signal Transduction - genetics; Light Signal Transduction - radiation effects; light signaling; microarray technology; Models, Biological; mutants; Mutation - genetics; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; pathogens; Phenotype; Phytochrome - genetics; Phytochrome - metabolism; Plant Diseases - genetics; Plant Diseases - immunology; plant immunity; Plant Immunity - genetics; Plant Immunity - radiation effects; proteins; Pseudomonas syringae; Pseudomonas syringae - drug effects; Pseudomonas syringae - physiology; reactive oxygen species; salicylic acid; Salicylic Acid - metabolism; seedling growth; signal transduction; transgenic plants; Up-Regulation - genetics; Up-Regulation - radiation effects; 信号因子; 叶绿素; 合成调控; 富含亮氨酸重复序列; 对光; 植物免疫; 生物合成途径; chlorophyll biosynthesis; light signaling; Arabidopsis; FAR1; salicylic acid; FHY3; plant immunity
• ISSN: 1672-9072; 1744-7909; 1744-7909
• DOI: 10.1111/jipb.12369

Light and chloroplast function is known to affect the plant immune response; however, the underlying mechanism remains elusive. We previously demonstrated that two light signaling factors, FAR-RED ELONGATED HYPOCOTYL 3（FHY3）and FAR-RED IMPAIRED RESPONSE 1（FAR1）, regulate chlorophyll biosynthesis and seedling growth via controlling HEMB1 expression in Arabidopsis thaliana. In this study, we reveal that FHY3 and FAR1 are involved in modulating plant immunity. We showed that the fhy3 far1 double null mutant displayed high levels of reactive oxygen species and salicylic acid（SA） and increased resistance to Pseudomonas syringae pathogen infection. Microarray analysis revealed that a large proportion of pathogen-related genes, particularly genes encoding nucleotide-binding and leucine-rich repeat domain resistant proteins, are highly induced in fhy3 far1. Genetic studies indicated that the defects of fhy3 far1 can be largely rescued by reducing SA signaling or blocking SA accumulation, and by overexpression of HEMB1, which encodes a 5-aminolevulinic acid dehydratase in the chlorophyll biosynthetic pathway.Furthermore, we found that transgenic plants with reduced expression of HEMB1 exhibit a phenotype similar to fhy3 far1.Taken together, this study demonstrates an important role of FHY3 and FAR1 in regulating plant immunity, through integrating chlorophyll biosynthesis and the SA signaling pathway.