title: The Xanthomonas campestris effector protein XopDXcc8004 triggers plant disease tolerance by targeting DELLA proteins.
abstract: Plants protect themselves from the harmful effects of pathogens by resistance and tolerance. Disease resistance, which eliminates pathogens, can be modulated by bacterial type III effectors. Little is known about whether disease tolerance, which sustains host fitness with a given pathogen burden, is regulated by effectors. Here, we examined the effects of the Xanthomonas effector protein XopDXcc8004 on plant disease defenses by constructing knockout and complemented Xanthomonas strains, and performing inoculation studies in radish (Raphanus sativus L. var. radiculus XiaoJinZhong) and Arabidopsis plants. XopDXcc8004 suppresses disease symptoms without changing bacterial titers in infected leaves. In Arabidopsis, XopDXcc8004 delays the hormone gibberellin (GA)-mediated degradation of RGA (repressor of ga1-3), one of five DELLA proteins that repress GA signaling and promote plant tolerance under biotic and abiotic stresses. The ERF-associated amphiphilic repression (EAR) motif-containing region of XopDXcc8004 interacts with the DELLA domain of RGA and might interfere with the GA-induced binding of GID1, a GA receptor, to RGA. The EAR motif was found to be present in a number of plant transcriptional regulators. Thus, our data suggest that bacterial pathogens might have evolved effectors, which probably mimic host components, to initiate disease tolerance and enhance their survival.
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.|Hainan Key Laboratory of Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou, 570228, China.|University of Chinese Academy of Sciences, Beijing, 100039, China.
authors.forename: Leitao
authors.initials: L
authors.lastname: Tan
authors.affiliation: Hainan Key Laboratory of Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou, 570228, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Rong
authors.affiliation: Hainan Key Laboratory of Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou, 570228, China.
authors.forename: Hongli
authors.initials: H
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.|Hainan Key Laboratory of Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou, 570228, China.
authors.forename: Yinhua
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.|Hainan Key Laboratory of Sustainable Utilization of Tropical Bioresources, Hainan University, Haikou, 570228, China.
authors.forename: Chaozu
authors.initials: C
authors.lastname: He
mesh_terms: D017360:Arabidopsis / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D031224:Raphanus / Q000382:microbiology*; D016959:Xanthomonas campestris / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005875:Gibberellins; D010940:Plant Proteins; C007842:gibberellic acid
keywords: DELLA proteins; ERF-associated amphiphilic repression (EAR) motif; Xanthomonas; XopDXcc8004; disease tolerance