title: Msp40 effector of root-knot nematode manipulates plant immunity to facilitate parasitism.
abstract: Root-knot nematodes (RKNs) are obligate biotrophic parasites that invade plant roots and engage in prolonged and intimate relationships with their hosts. Nematode secretions, some of which have immunosuppressing activity, play essential roles in successful parasitism; however, their mechanisms of action remain largely unknown. Here, we show that the RKN-specific gene MiMsp40, cloned from Meloidogyne incognita, is expressed exclusively in subventral oesophageal gland cells and is strongly upregulated during early parasitic stages. Arabidopsis plants overexpressing MiMsp40 were more susceptible to nematode infection than were wild type plants. Conversely, the host-derived MiMsp40 RNAi suppressed nematode parasitism and/or reproduction. Moreover, overexpression of MiMsp40 in plants suppressed the deposition of callose and the expression of marker genes for bacterial elicitor elf18-triggered immunity. Transient expression of MiMsp40 prevented Bax-triggered defence-related programmed cell death. Co-agroinfiltration assays indicated that MiMsp40 also suppressed macroscopic cell death triggered by MAPK cascades or by the ETI cognate elicitors R3a/Avr3a. Together, these results demonstrate that MiMsp40 is a novel Meloidogyne-specific effector that is injected into plant cells by early parasitic stages of the nematode and that plays a role in suppressing PTI and/or ETI signals to facilitate RKN parasitism.
authors.affiliation: Department of Plant Pathology and Key Laboratory of Plant Pathology of Ministry of Agriculture, China Agricultural University, Beijing 100193, P. R. China.|Tropical Crops Genetic Resources Institute, CATAS/Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China, Danzhou, Hainan 571737, P. R. China.
authors.forename: Junhai
authors.initials: J
authors.lastname: Niu
authors.affiliation: Department of Plant Pathology and Key Laboratory of Plant Pathology of Ministry of Agriculture, China Agricultural University, Beijing 100193, P. R. China.
authors.forename: Pei
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Plant Pathology and Key Laboratory of Plant Pathology of Ministry of Agriculture, China Agricultural University, Beijing 100193, P. R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Plant Pathology and Key Laboratory of Plant Pathology of Ministry of Agriculture, China Agricultural University, Beijing 100193, P. R. China.
authors.forename: Changlong
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Plant Pathology and Key Laboratory of Plant Pathology of Ministry of Agriculture, China Agricultural University, Beijing 100193, P. R. China.
authors.forename: Quanxin
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Tropical Crops Genetic Resources Institute, CATAS/Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China, Danzhou, Hainan 571737, P. R. China.
authors.forename: Junmei
authors.initials: J
authors.lastname: Yin
authors.affiliation: Tropical Crops Genetic Resources Institute, CATAS/Key Laboratory of Crop Gene Resources and Germplasm Enhancement in Southern China, Danzhou, Hainan 571737, P. R. China.
authors.forename: Guangsui
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Plant Pathology and Key Laboratory of Plant Pathology of Ministry of Agriculture, China Agricultural University, Beijing 100193, P. R. China.
authors.forename: Heng
authors.initials: H
authors.lastname: Jian
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D017360:Arabidopsis / Q000033:anatomy & histology / Q000235:genetics / Q000276:immunology* / Q000469:parasitology*; D004198:Disease Susceptibility; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D016678:Genome; D015801:Helminth Proteins / Q000737:chemistry / Q000378:metabolism*; D010271:Parasites / Q000502:physiology*; D010641:Phenotype; D010802:Phylogeny; D059828:Plant Cells / Q000378:metabolism; D010935:Plant Diseases / Q000469:parasitology*; D057865:Plant Immunity; D018517:Plant Roots / Q000469:parasitology; D030821:Plants, Genetically Modified; D034622:RNA Interference; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism; D014431:Tylenchoidea / Q000235:genetics / Q000502:physiology*
chemical_list: D015801:Helminth Proteins