title: NBS-LRR Protein Pik-H4 Interacts with OsBIHD1 to Balance Rice Blast Resistance and Growth by Coordinating Ethylene-Brassinosteroid Pathway.
abstract: The regulation of innate immunity and plant growth, along with the trade-off between them, affects the defense and recovery mechanisms of the plant after it is attacked by pathogens. Although it is known that hormonal crosstalk plays a major role in regulating interaction of plant growth and PAMP-triggered immunity, the relationship between plant growth and effector-triggered immunity (ETI) remains unclear. In a large-scale yeast two-hybrid screening for Pik-H4-interacting proteins, a homeodomain transcription factor OsBIHD1 was identified, which is previously known to function in biotic and abiotic stress responses. The knockout ofOsBIHD1in rice lines carryingPik-H4largely compromised the resistance of the rice lines toMagnaporthe oryzae, the fungus that causes rice blast. While overexpression ofOsBIHD1resulted in enhanced expression of the pathogenesis-related (PR) and ethylene (ET) synthesis genes. Moreover, OsBIHD1 was also found to directly bind to the promoter region of ethylene-synthesis enzyme OsACO3. In addition,OsBIHD1overexpression or deficiency provoked dwarfism and reduced brassinosteroid (BR) insensitivity through repressing the expression of several critical genes involved in BR biosynthesis and BR signaling. DuringM. oryzaeinfection, transcript levels of the crucial BR catabolic genes (CYP734A2,CYP734A4, andCYP734A6) were significantly up-regulated inOsBIHD1-OXplants. Furthermore, OsBIHD1 was found to be capable of binding to the sequence-specificcis-elements on the promoters ofCYP734A2to suppress the plant growth under fungal invasion. Our results collectively suggest a model that OsBIHD1 is required for Pik-H4-mediated blast resistance through modulating the trade-off between resistance and growth by coordinating brassinosteroid-ethylene pathway.
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Shuangyu
authors.initials: S
authors.lastname: Dong
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Fengwei
authors.initials: F
authors.lastname: Gu
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Guili
authors.initials: G
authors.lastname: Yang
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Huang
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Wuming
authors.initials: W
authors.lastname: Xiao
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Yongzhu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Guo
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: National Engineering Research Center of Plant Space Breeding, South China Agricultural University Guangzhou, China.
authors.forename: Jiafeng
authors.initials: J
authors.lastname: Wang
keywords: NBS-LRR resistance gene; brassinosteroid signaling; ethylenes; fungal resistance.; homeodomain proteins