title: The tomato UV-damaged DNA-binding protein-1 (DDB1) is implicated in pathogenesis-related (PR) gene expression and resistance to Agrobacterium tumefaciens.
abstract: Plants defend themselves against potential pathogens via the recognition of pathogen-associated molecular patterns (PAMPs). However, the molecular mechanisms underlying this PAMP-triggered immunity (PTI) are largely unknown. In this study, we show that tomato HP1/DDB1, coding for a key component of the CUL4-based ubiquitin E3 ligase complex, is required for resistance to Agrobacterium tumefaciens. We found that the DDB1-deficient mutant (high pigment-1, hp1) is susceptible to nontumorigenic A. tumefaciens. The efficiency of callus generation from the hp1 cotyledons was extremely low as a result of the necrosis caused by Agrobacterium infection. On infiltration of nontumorigenic A. tumefaciens into leaves, the hp1 mutant moderately supported Agrobacterium growth and developed disease symptoms, but the expression of the pathogenesis-related gene SlPR1a1 and several PTI marker genes was compromised at different levels. Moreover, exogenous application of salicylic acid (SA) triggered SlPR1a1 gene expression and enhanced resistance to A. tumefaciens in wild-type tomato plants, whereas these SA-regulated defence responses were abolished in hp1 mutant plants. Thus, HP1/DDB1 may function through interaction with the SA-regulated PTI pathway in resistance against Agrobacterium infection.
authors: Ministry of Education Key Laboratory for Bio-resource and Eco-environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610064, China.
authors: Jikai
authors: J
authors: Liu
authors: Hanjing
authors: H
authors: Li
authors: Min
authors: M
authors: Miao
authors: Xiaofeng
authors: X
authors: Tang
authors: Jim
authors: J
authors: Giovannoni
authors: Fangming
authors: F
authors: Xiao
authors: Yongsheng
authors: Y
authors: Liu
mesh_terms: D016960:Agrobacterium tumefaciens / Q000187:drug effects / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects; D018548:Cotyledon / Q000187:drug effects / Q000382:microbiology / Q000528:radiation effects; D060467:Disease Resistance / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D017343:Genes, Plant / Q000235:genetics; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology* / Q000528:radiation effects; D009154:Mutation / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000382:microbiology / Q000528:radiation effects; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D010941:Plant Tumors / Q000382:microbiology; D020156:Salicylic Acid / Q000494:pharmacology; D014170:Transformation, Genetic / Q000187:drug effects / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D010940:Plant Proteins; D020156:Salicylic Acid