Plants secrete defense molecules into the extracellular space (the apoplast) to combat attacking microbes. However, the mechanisms by which successful pathogens subvert plant apoplastic immunity remain poorly understo...Plants secrete defense molecules into the extracellular space (the apoplast) to combat attacking microbes. However, the mechanisms by which successful pathogens subvert plant apoplastic immunity remain poorly understood. In this study, we show that PsAvh240, a membrane-localized effector of the soybean pathogen Phytophthora sojae, promotes P. sojae infection in soybean hairy roots. We found that PsAvh240 interacts with the soybean-resistant aspartic protease GmAP1 in planta and suppresses the secretion of GmAP1 into the apoplast. By solving its crystal structure we revealed that PsAvh240 contain six a helices and two WY motifs. The first two a helices of PsAvh240 are responsible for its plasma membrane-localization and are required for PsAvh240's interaction with GmAP1. The second WY motifs of two PsAvh240 molecules form a handshake arrangement resulting in a handshake-like dimer. This dimerization is required for the effector's repression of GmAP1 secretion. Taken together, these data reveal that PsAvh240 localizes at the plasma membrane to interfere with GmAP1 secretion, which represents an effective mechanism by which effector proteins suppress plant apoplastic immunity.展开更多
Objective:To investigate the morphological structure of ovarian follicular cells and biochemical parameters of both ovaries and fat bodies(sites of vitellogenesis)from Rhodnius(R.)prolixus infected with Trypanosoma(T....Objective:To investigate the morphological structure of ovarian follicular cells and biochemical parameters of both ovaries and fat bodies(sites of vitellogenesis)from Rhodnius(R.)prolixus infected with Trypanosoma(T.)rangeli.Methods:Adult virgin females of R.prolixus were fed upon a membrane apparatus containing heat-inactivated citrated rabbit blood and a suspension of T.rangeli epimastigotes(Macias strain).Females from the control group and all the males received parasite-free blood.Transmission electron microscopy was used to reveal the morphological aspects of ovarian follicle cells in both control and parasite-infected groups.Protein profile,proteolytic activities and Western blotting analyses were performed in either ovary or fat body samples of control and parasite-infected groups.Results:According to the ultrastructural data,T.rangeli infection elicited a degeneration process in the ovarian follicular cells of R.prolixus.Proteolytic assays indicated a reduction in the activity of aspartic peptidases in the ovary and fat body from parasite-infected group,while a significant increase in the cysteine peptidase activity was measured in both insect organs.Additionally,immunoblotting revealed that vitellogenin was overexpressed in the ovary of parasite-infected insects.Conclusions:T.rangeli infection seems to elicit an early programmed cell death in the ovarian follicle cells as well as induces the modulation on the activities of different peptidase classes in either ovaries or fat bodies and the overexpression of the vitellogenin in the ovary of R.prolixus.展开更多
基金supported by grants to Yuanchao Wang from the China National Funds for Innovative Research Groups(31721004)the key program of the National Natural Science Foundation of China(31430073)+2 种基金the Chinese Modern Agricultural Industry Technology System(CARS-004-PS14)the National Key R&D Program of China(SQ2018YFD020042)Research in the W.X.laboratory is supported by the Chinese Thousand Talents Plan and the Chinese Academy of Sciences.B.G.is supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX18.0662).
文摘Plants secrete defense molecules into the extracellular space (the apoplast) to combat attacking microbes. However, the mechanisms by which successful pathogens subvert plant apoplastic immunity remain poorly understood. In this study, we show that PsAvh240, a membrane-localized effector of the soybean pathogen Phytophthora sojae, promotes P. sojae infection in soybean hairy roots. We found that PsAvh240 interacts with the soybean-resistant aspartic protease GmAP1 in planta and suppresses the secretion of GmAP1 into the apoplast. By solving its crystal structure we revealed that PsAvh240 contain six a helices and two WY motifs. The first two a helices of PsAvh240 are responsible for its plasma membrane-localization and are required for PsAvh240's interaction with GmAP1. The second WY motifs of two PsAvh240 molecules form a handshake arrangement resulting in a handshake-like dimer. This dimerization is required for the effector's repression of GmAP1 secretion. Taken together, these data reveal that PsAvh240 localizes at the plasma membrane to interfere with GmAP1 secretion, which represents an effective mechanism by which effector proteins suppress plant apoplastic immunity.
基金This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior,Brasil(CAPES,Finance Code 001).
文摘Objective:To investigate the morphological structure of ovarian follicular cells and biochemical parameters of both ovaries and fat bodies(sites of vitellogenesis)from Rhodnius(R.)prolixus infected with Trypanosoma(T.)rangeli.Methods:Adult virgin females of R.prolixus were fed upon a membrane apparatus containing heat-inactivated citrated rabbit blood and a suspension of T.rangeli epimastigotes(Macias strain).Females from the control group and all the males received parasite-free blood.Transmission electron microscopy was used to reveal the morphological aspects of ovarian follicle cells in both control and parasite-infected groups.Protein profile,proteolytic activities and Western blotting analyses were performed in either ovary or fat body samples of control and parasite-infected groups.Results:According to the ultrastructural data,T.rangeli infection elicited a degeneration process in the ovarian follicular cells of R.prolixus.Proteolytic assays indicated a reduction in the activity of aspartic peptidases in the ovary and fat body from parasite-infected group,while a significant increase in the cysteine peptidase activity was measured in both insect organs.Additionally,immunoblotting revealed that vitellogenin was overexpressed in the ovary of parasite-infected insects.Conclusions:T.rangeli infection seems to elicit an early programmed cell death in the ovarian follicle cells as well as induces the modulation on the activities of different peptidase classes in either ovaries or fat bodies and the overexpression of the vitellogenin in the ovary of R.prolixus.