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A pair of light signaling factors FHY3 and FAR1 regulates plant immunity by modulating chlorophyll biosynthesis
Author(s) -
Wang Wanqing,
Tang Weijiang,
Ma Tingting,
Niu De,
Jin Jing Bo,
Wang Haiyang,
Lin Rongcheng
Publication year - 2016
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.12369
Subject(s) - biology , arabidopsis thaliana , arabidopsis , microbiology and biotechnology , plant immunity , plant defense against herbivory , signal transduction , pseudomonas syringae , chloroplast , salicylic acid , biochemistry , mutant , gene
Abstract 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.