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標題: 菌質體之分泌蛋白在擬南芥中調節缺磷反應與防禦機制的探討
The Phytoplasma Effector Modulates Phosphate Homeostasis and Defense Response in Arabidopsis
作者: 呂晏婷
Lu, Yen-Ting
關鍵字: 菌質體
Pi deficiency
defense response
出版社: 生物科技學研究所
引用: Aguilar-Martinez, J.A., Poza-Carrion, C., and Cubas, P. (2007). Arabidopsis BRANCHED1 acts as an integrator of branching signals within axillary buds. The Plant cell 19, 458-472. Al-Ghazi, Y., Muller, B., Pinloche, S., Tranbarger, T.J., Nacry, P., Rossignol, M., Tardieu, F., and Doumas, P. (2003). Temporal responses of Arabidopsis root architecture to phosphate starvation: evidence for the involvement of auxin signalling. Plant Cell and Environment 26, 1053-1066. Arashida, R., Kakizawa, S., Hoshi, A., Ishii, Y., Jung, H.Y., Kagiwada, S., Yamaji, Y., Oshima, K., and Namba, S. (2008). Heterogeneic dynamics of the structures of multiple gene clusters in two pathogenetically different lines originating from the same phytoplasma. DNA and cell biology 27, 209-217. Aung, K., Lin, S.I., Wu, C.C., Huang, Y.T., Su, C.L., and Chiou, T.J. (2006). pho2, a phosphate overaccumulator, is caused by a nonsense mutation in a microRNA399 target gene. Plant physiology 141, 1000-1011. Bai, X., Ammar, E.D., and Hogenhout, S.A. (2007). A secreted effector protein of AY-WB phytoplasma accumulates in nuclei and alters gene expression of host plant cells, and is detected in various tissues of the leafhopper Macrosteles quadrilineatus. Bulletin of Insectology 60, 2. Bai, X., Correa, V.R., Toruno, T.Y., Ammar el, D., Kamoun, S., and Hogenhout, S.A. (2009). AY-WB phytoplasma secretes a protein that targets plant cell nuclei. Molecular plant-microbe interactions : MPMI 22, 18-30. Bai, X., Zhang, J., Ewing, A., Miller, S.A., Jancso Radek, A., Shevchenko, D.V., Tsukerman, K., Walunas, T., Lapidus, A., Campbell, J.W., and Hogenhout, S.A. (2006). Living with genome instability: the adaptation of phytoplasmas to diverse environments of their insect and plant hosts. Journal of bacteriology 188, 3682-3696. Bari, R., Datt Pant, B., Stitt, M., and Scheible, W.R. (2006). PHO2, microRNA399, and PHR1 define a phosphate-signaling pathway in plants. Plant physiology 141, 988-999. Bariola, P.A., Howard, C.J., Taylor, C.B., Verburg, M.T., Jaglan, V.D., and Green, P.J. (1994). The Arabidopsis ribonuclease gene RNS1 is tightly controlled in response to phosphate limitation. The Plant journal : for cell and molecular biology 6, 673-685. Bartel, D.P. (2004). MicroRNAs: genomics, biogenesis, mechanism, and function. Cell 116, 281-297. Baulcombe, D.C., Chapman, S., and Santa Cruz, S. (1995). Jellyfish green fluorescent protein as a reporter for virus infections. The Plant journal : for cell and molecular biology 7, 1045-1053. Bertaccini, A. (2007). Phytoplasmas: diversity, taxonomy, and epidemiology. Frontiers in bioscience : a journal and virtual library 12, 673-689. Bertaccini, A., and Duduk, B. (2009). Phytoplasma and phytoplasma diseases: a review of recent research. Phytopathol Mediterr 48, 355-378. Bos, J.I., Prince, D., Pitino, M., Maffei, M.E., Win, J., and Hogenhout, S.A. (2010). A functional genomics approach identifies candidate effectors from the aphid species Myzus persicae (green peach aphid). PLoS genetics 6, e1001216. Bosco, D., Galetto, L., Leoncini, P., Saracco, P., Raccah, B., and Marzachi, C. (2007). Interrelationships between "Candidatus Phytoplasma asteris" and its leafhopper vectors (Homoptera: Cicadellidae). Journal of economic entomology 100, 1504-1511. Bove, J.M. (2006). Huanglongbing: A destructive, newly-emerging, century-old disease of citrus. Journal of Plant Pathology 88, 7-37. Carrington, J.C., and Ambros, V. (2003). Role of microRNAs in plant and animal development. Science 301, 336-338. Chen, W.Y., and Lin, C.P. (2011). Characterization of Catharanthus roseus Genes Regulated Differentially by Peanut Witches'' Broom Phytoplasma Infection. J Phytopathol 159, 505-510. Chen, W.Y., Lin, C.P., Yen, Y.-F., and Shih, H.T. (2006). 翠菊黃萎病之診斷鑑定與防治. 豐年社 56, 60-63. Chiou, T.J., and Lin, S.I. (2011). Signaling network in sensing phosphate availability in plants. Annual review of plant biology 62, 185-206. Chiou, T.J., Aung, K., Lin, S.I., Wu, C.C., Chiang, S.F., and Su, C.L. (2006). Regulation of phosphate homeostasis by MicroRNA in Arabidopsis. The Plant cell 18, 412-421. Christensen, N.M., Axelsen, K.B., Nicolaisen, M., and Schulz, A. (2005). Phytoplasmas and their interactions with hosts. Trends in plant science 10, 526-535. Chung, W.C., Chen, L.L., Lo, W.S., Lin, C.P., and Kuo, C.H. (2013). Comparative analysis of the peanut witches''-broom phytoplasma genome reveals horizontal transfer of potential mobile units and effectors. PloS one 8, e62770. Ciereszko, I., Johansson, H., and Kleczkowski, L.A. (2005). Interactive effects of phosphate deficiency, sucrose and light/dark conditions on gene expression of UDP-glucose pyrophosphorylase in Arabidopsis. Journal of plant physiology 162, 343-353. Delaney, T.P., Uknes, S., Vernooij, B., Friedrich, L., Weymann, K., Negrotto, D., Gaffney, T., Gut-Rella, M., Kessmann, H., Ward, E., and Ryals, J. (1994). A central role of salicylic Acid in plant disease resistance. Science 266, 1247-1250. Delhaize, E., and Randall, P.J. (1995). Characterization of a Phosphate-Accumulator Mutant of Arabidopsis thaliana. Plant physiology 107, 207-213. Desveaux, D., Marechal, A., and Brisson, N. (2005). Whirly transcription factors: defense gene regulation and beyond. Trends in plant science 10, 95-102. Desveaux, D., Subramaniam, R., Despres, C., Mess, J.N., Levesque, C., Fobert, P.R., Dangl, J.L., and Brisson, N. (2004). A "Whirly" transcription factor is required for salicylic acid-dependent disease resistance in Arabidopsis. Developmental cell 6, 229-240. Doerner, P. (2008). Phosphate starvation signaling: a threesome controls systemic P(i) homeostasis. Current opinion in plant biology 11, 536-540. Doi, Y., Teranaka, M., Yora, K., and Asuyama, H. (1967). Mycoplasma- or PLT group-like microorganisms found in the phloem elements of plants infected with mulberry dwarf, potato witches’ broom, aster yellows or paulownia witches’ broom. Ann. Phytopathol. Soc. Jpn. Efroni, I., Blum, E., Goldshmidt, A., and Eshed, Y. (2008). A protracted and dynamic maturation schedule underlies Arabidopsis leaf development. The Plant cell 20, 2293-2306. Eulgem, T. (2005). Regulation of the Arabidopsis defense transcriptome. Trends in plant science 10, 71-78. Eulgem, T., and Somssich, I.E. (2007). Networks of WRKY transcription factors in defense signaling. Current opinion in plant biology 10, 366-371. Fujii, H., Chiou, T.J., Lin, S.I., Aung, K., and Zhu, J.K. (2005). A miRNA involved in phosphate-starvation response in Arabidopsis. Current biology : CB 15, 2038-2043. Gaffney, T., Friedrich, L., Vernooij, B., Negrotto, D., Nye, G., Uknes, S., Ward, E., Kessmann, H., and Ryals, J. (1993). Requirement of salicylic Acid for the induction of systemic acquired resistance. Science 261, 754-756. Garcion, C., and M´etraux, J.P. (2006). Salicylic acid. In Plant Hormone Signaling 24, 229-255. Grant, S.R., Fisher, E.J., Chang, J.H., Mole, B.M., and Dangl, J.L. (2006). Subterfuge and manipulation: type III effector proteins of phytopathogenic bacteria. Annual review of microbiology 60, 425-449. Hause, B., and Fester, T. (2005). Molecular and cell biology of arbuscular mycorrhizal symbiosis. Planta 221, 184-196. Hogenhout, S.A., and Music, M.S. (2010). Phytoplasma genomics, from sequencing to comparative and functional genomics: what have we learnt? Phytoplasmas. Genomes, Plant Hosts and Vectors. Wallingford, UK: CABI, 18. Hogenhout, S.A., Van der Hoorn, R.A., Terauchi, R., and Kamoun, S. (2009). Emerging concepts in effector biology of plant-associated organisms. Molecular plant-microbe interactions : MPMI 22, 115-122. Hogenhout, S.A., Oshima, K., Ammar el, D., Kakizawa, S., Kingdom, H.N., and Namba, S. (2008). Phytoplasmas: bacteria that manipulate plants and insects. Molecular plant pathology 9, 403-423. Hoshi, A., Oshima, K., Kakizawa, S., Ishii, Y., Ozeki, J., Hashimoto, M., Komatsu, K., Kagiwada, S., Yamaji, Y., and Namba, S. (2009). A unique virulence factor for proliferation and dwarfism in plants identified from a phytopathogenic bacterium. Proceedings of the National Academy of Sciences of the United States of America 106, 6416-6421. Hung, T.-H., and Lin, C.-P. (2011). 台灣農作物重要植物菌質體病害研究現況. 農作物害蟲及其媒介病害整合防治技術研討會專刊, 63-72. Jain, A., Poling, M.D., Karthikeyan, A.S., Blakeslee, J.J., Peer, W.A., Titapiwatanakun, B., Murphy, A.S., and Raghothama, K.G. (2007). Differential effects of sucrose and auxin on localized phosphate deficiency-induced modulation of different traits of root system architecture in Arabidopsis. Plant physiology 144, 232-247. Kakizawa, S., Oshima, K., Nishigawa, H., Jung, H.Y., Wei, W., Suzuki, S., Tanaka, M., Miyata, S., Ugaki, M., and Namba, S. (2004). Secretion of immunodominant membrane protein from onion yellows phytoplasma through the Sec protein-translocation system in Escherichia coli. Microbiology 150, 135-142. Kaplan, I., Halitschke, R., Kessler, A., Sardanelli, S., and Denno, R.F. (2008). Constitutive and induced defenses to herbivory in above- and belowground plant tissues. Ecology 89, 392-406. Karandashov, V., and Bucher, M. (2005). Symbiotic phosphate transport in arbuscular mycorrhizas. Trends in plant science 10, 22-29. Kosma, D.K., Nemacheck, J.A., Jenks, M.A., and Williams, C.E. (2010). Changes in properties of wheat leaf cuticle during interactions with Hessian fly. The Plant journal : for cell and molecular biology 63, 31-43. Kube, M., Schneider, B., Kuhl, H., Dandekar, T., Heitmann, K., Migdoll, A.M., Reinhardt, R., and Seemuller, E. (2008). The linear chromosome of the plant-pathogenic mycoplasma ''Candidatus Phytoplasma mali''. BMC genomics 9, 306. Lawton, K., Weymann, K., Friedrich, L., Vernooij, B., Uknes, S., and Ryals, J. (1995). Systemic acquired resistance in Arabidopsis requires salicylic acid but not ethylene. Molecular plant-microbe interactions : MPMI 8, 863-870. Lebel, E., Heifetz, P., Thorne, L., Uknes, S., Ryals, J., and Ward, E. (1998). Functional analysis of regulatory sequences controlling PR-1 gene expression in Arabidopsis. The Plant journal : for cell and molecular biology 16, 223-233. Lee, I.M., Davis, R.E., and Gundersen-Rindal, D.E. (2000). Phytoplasma: phytopathogenic mollicutes. Annual review of microbiology 54, 221-255. Lee, I.M., Bottner, K.D., Secor, G., and Rivera-Varas, V. (2006). "Candidatus Phytoplasma americanum", a phytoplasma associated with a potato purple top wilt disease complex. International journal of systematic and evolutionary microbiology 56, 1593-1597. Lee, I.M., Bottner-Parker, K.D., Zhao, Y., Davis, R.E., and Harrison, N.A. (2010). Phylogenetic analysis and delineation of phytoplasmas based on secY gene sequences. International journal of systematic and evolutionary microbiology 60, 2887-2897. Li, J., Brader, G., and Palva, E.T. (2004). The WRKY70 transcription factor: a node of convergence for jasmonate-mediated and salicylate-mediated signals in plant defense. The Plant cell 16, 319-331. Li, J., Brader, G., Kariola, T., and Palva, E.T. (2006). WRKY70 modulates the selection of signaling pathways in plant defense. The Plant journal : for cell and molecular biology 46, 477-491. Loake, G., and Grant, M. (2007). Salicylic acid in plant defence--the players and protagonists. Current opinion in plant biology 10, 466-472. Lopez-Bucio, J., Cruz-Ramirez, A., and Herrera-Estrella, L. (2003). The role of nutrient availability in regulating root architecture. Current opinion in plant biology 6, 280-287. Lopez-Bucio, J., Hernandez-Abreu, E., Sanchez-Calderon, L., Nieto-Jacobo, M.F., Simpson, J., and Herrera-Estrella, L. (2002). Phosphate availability alters architecture and causes changes in hormone sensitivity in the Arabidopsis root system. Plant physiology 129, 244-256. Lopez-Bucio, J., Hernandez-Abreu, E., Sanchez-Calderon, L., Perez-Torres, A., Rampey, R.A., Bartel, B., and Herrera-Estrella, L. (2005). An auxin transport independent pathway is involved in phosphate stress-induced root architectural alterations in Arabidopsis. Identification of BIG as a mediator of auxin in pericycle cell activation. Plant physiology 137, 681-691. MacLean, A.M., Sugio, A., Makarova, O.V., Findlay, K.C., Grieve, V.M., Toth, R., Nicolaisen, M., and Hogenhout, S.A. (2011). Phytoplasma effector SAP54 induces indeterminate leaf-like flower development in Arabidopsis plants. Plant physiology 157, 831-841. Marschner, H. (1995). Mineral Nutrition of Higher Plants. London: Academic. Martin-Trillo, M., and Cubas, P. (2010). TCP genes: a family snapshot ten years later. Trends in plant science 15, 31-39. Martin, A.C., del Pozo, J.C., Iglesias, J., Rubio, V., Solano, R., de La Pena, A., Leyva, A., and Paz-Ares, J. (2000). Influence of cytokinins on the expression of phosphate starvation responsive genes in Arabidopsis. The Plant journal : for cell and molecular biology 24, 559-567. Miura, K., Rus, A., Sharkhuu, A., Yokoi, S., Karthikeyan, A.S., Raghothama, K.G., Baek, D., Koo, Y.D., Jin, J.B., Bressan, R.A., Yun, D.J., and Hasegawa, P.M. (2005). The Arabidopsis SUMO E3 ligase SIZ1 controls phosphate deficiency responses. Proceedings of the National Academy of Sciences of the United States of America 102, 7760-7765. Mockaitis, K., and Estelle, M. (2008). Auxin receptors and plant development: a new signaling paradigm. Annual review of cell and developmental biology 24, 55-80. Nacry, P., Canivenc, G., Muller, B., Azmi, A., Van Onckelen, H., Rossignol, M., and Doumas, P. (2005). A role for auxin redistribution in the responses of the root system architecture to phosphate starvation in Arabidopsis. Plant physiology 138, 2061-2074. Nawrath, C., and Metraux, J.P. (1999). Salicylic acid induction-deficient mutants of Arabidopsis express PR-2 and PR-5 and accumulate high levels of camalexin after pathogen inoculation. The Plant cell 11, 1393-1404. Nawrath, C., Heck, S., Parinthawong, N., and Metraux, J.P. (2002). EDS5, an essential component of salicylic acid-dependent signaling for disease resistance in Arabidopsis, is a member of the MATE transporter family. The Plant cell 14, 275-286. Oshima, K., Kakizawa, S., Nishigawa, H., Jung, H.Y., Wei, W., Suzuki, S., Arashida, R., Nakata, D., Miyata, S., Ugaki, M., and Namba, S. (2004). Reductive evolution suggested from the complete genome sequence of a plant-pathogenic phytoplasma. Nature genetics 36, 27-29. Pallas, J., Paiva, N., Lamb, C., and Dixon, R. (1996). Tobacco plants epigenetically suppressed in phenylalanine ammonia-lyase expression do not develop systemic acquired resistance in response to infection by tobacco mosaic virus. Plant J. 10, 281-293. Perez-Donoso, A.G., Sun, Q., Roper, M.C., Greve, L.C., Kirkpatrick, B., and Labavitch, J.M. (2010). Cell wall-degrading enzymes enlarge the pore size of intervessel pit membranes in healthy and Xylella fastidiosa-infected grapevines. Plant physiology 152, 1748-1759. Perez-Torres, C.A., Lopez-Bucio, J., Cruz-Ramirez, A., Ibarra-Laclette, E., Dharmasiri, S., Estelle, M., and Herrera-Estrella, L. (2008). Phosphate availability alters lateral root development in Arabidopsis by modulating auxin sensitivity via a mechanism involving the TIR1 auxin receptor. The Plant cell 20, 3258-3272. Petrasek, J., Mravec, J., Bouchard, R., Blakeslee, J.J., Abas, M., Seifertova, D., Wisniewska, J., Tadele, Z., Kubes, M., Covanova, M., Dhonukshe, P., Skupa, P., Benkova, E., Perry, L., Krecek, P., Lee, O.R., Fink, G.R., Geisler, M., Murphy, A.S., Luschnig, C., Zazimalova, E., and Friml, J. (2006). PIN proteins perform a rate-limiting function in cellular auxin efflux. Science 312, 914-918. Raffaele, S., Rivas, S., and Roby, D. (2006). An essential role for salicylic acid in AtMYB30-mediated control of the hypersensitive cell death program in Arabidopsis. FEBS letters 580, 3498-3504. Raghothama, K.G. (1999). Phosphate Acquisition. Annual review of plant physiology and plant molecular biology 50, 665-693. Rosch, J., and Caparon, M. (2004). A microdomain for protein secretion in Gram-positive bacteria. Science 304, 1513-1515. Rubio, V., Linhares, F., Solano, R., Martin, A.C., Iglesias, J., Leyva, A., and Paz-Ares, J. (2001). A conserved MYB transcription factor involved in phosphate starvation signaling both in vascular plants and in unicellular algae. Genes & development 15, 2122-2133. Ruiz-Ferrer, V., and Voinnet, O. (2009). Roles of plant small RNAs in biotic stress responses. Annual review of plant biology 60, 485-510. Schneider, B., Seemüller, E., Smart, C.D., and Kirkpatrick, B.C. (1995). Phylogenetic classification of plant pathogenic mycoplasma-like organisms or phytoplasmas. Molecular and diagnostic procedures in mycoplasmology 1, 12. Shah, J. (2003). The salicylic acid loop in plant defense. Current opinion in plant biology 6, 365-371. Shin, H., Shin, H.S., Chen, R., and Harrison, M.J. (2006). Loss of At4 function impacts phosphate distribution between the roots and the shoots during phosphate starvation. The Plant journal : for cell and molecular biology 45, 712-726. Smith, S.E., Smith, F.A., and Jakobsen, I. (2003). Mycorrhizal fungi can dominate phosphate supply to plants irrespective of growth responses. Plant physiology 133, 16-20. Spoel, S.H., Koornneef, A., Claessens, S.M., Korzelius, J.P., Van Pelt, J.A., Mueller, M.J., Buchala, A.J., Metraux, J.P., Brown, R., Kazan, K., Van Loon, L.C., Dong, X., and Pieterse, C.M. (2003). NPR1 modulates cross-talk between salicylate- and jasmonate-dependent defense pathways through a novel function in the cytosol. The Plant cell 15, 760-770. Strawn, M.A., Marr, S.K., Inoue, K., Inada, N., Zubieta, C., and Wildermuth, M.C. (2007). Arabidopsis isochorismate synthase functional in pathogen-induced salicylate biosynthesis exhibits properties consistent with a role in diverse stress responses. The Journal of biological chemistry 282, 5919-5933. Sugio, A., Kingdom, H.N., Nicholls, V.M., and Hogenhout, S.A. (2010). The phytoplasma effector protein SAP11 improves vector fitness. Congr. Int. Org. Mycoplasmol., 18th, Cianciano Terme 47:82. Sugio, A., MacLean, A.M., Kingdom, H.N., Grieve, V.M., Manimekalai, R., and Hogenhout, S.A. (2011). Diverse targets of phytoplasma effectors: from plant development to defense against insects. Annual review of phytopathology 49, 175-195. Svistoonoff, S., Creff, A., Reymond, M., Sigoillot-Claude, C., Ricaud, L., Blanchet, A., Nussaume, L., and Desnos, T. (2007). Root tip contact with low-phosphate media reprograms plant root architecture. Nature genetics 39, 792-796. Tawaraya, K., Hirose, R., and Wagatsuma, T. (2012). Inoculation of arbuscular mycorrhizal fungi can substantially reduce phosphate fertilizer application to Allium fistulosum L. and achieve marketable yield under field condition. Biol Fert Soils 48, 839-843. Tiessen, H. (2008). Phosphorus in the global environment. The Ecophysiology of Plant-Phosphorus Interactions 7, 7. Timpte, C., Wilson, A.K., and Estelle, M. (1994). The axr2-1 mutation of Arabidopsis thaliana is a gain-of-function mutation that disrupts an early step in auxin response. Genetics 138, 1239-1249. Tooker, J.F., Peiffer, M., Luthe, D.S., and Felton, G.W. (2010). Trichomes as sensors: detecting activity on the leaf surface. Plant signaling & behavior 5, 73-75. Tran-Nguyen, L.T., Kube, M., Schneider, B., Reinhardt, R., and Gibb, K.S. (2008). Comparative genome analysis of "Candidatus Phytoplasma australiense" (subgroup tuf-Australia I; rp-A) and "Ca. Phytoplasma asteris" Strains OY-M and AY-WB. Journal of bacteriology 190, 3979-3991. Verberne, M.C., Verpoorte, R., Bol, J.F., Mercado-Blanco, J., and Linthorst, H.J. (2000). Overproduction of salicylic acid in plants by bacterial transgenes enhances pathogen resistance. Nature biotechnology 18, 779-783. Vernooij, B., Friedrich, L., Morse, A., Reist, R., Kolditz-Jawhar, R., Ward, E., Uknes, S., Kessmann, H., and Ryals, J. (1994). Salicylic Acid Is Not the Translocated Signal Responsible for Inducing Systemic Acquired Resistance but Is Required in Signal Transduction. The Plant cell 6, 959-965. Vlot, A.C., Dempsey, D.A., and Klessig, D.F. (2009). Salicylic Acid, a multifaceted hormone to combat disease. Annual review of phytopathology 47, 177-206. Wang, D., Amornsiripanitch, N., and Dong, X. (2006). A genomic approach to identify regulatory nodes in the transcriptional network of systemic acquired resistance in plants. PLoS pathogens 2, e123. Wildermuth, M.C. (2006). Variations on a theme: synthesis and modification of plant benzoic acids. Current opinion in plant biology 9, 288-296. Wildermuth, M.C., Dewdney, J., Wu, G., and Ausubel, F.M. (2001). Isochorismate synthase is required to synthesize salicylic acid for plant defence. Nature 414, 562-565. Wilson, M.R., and Turner, J.A. (2010). Leafhopper, Planthopper and Psyllid Vectors of Plant Disease. Amgueddfa Cymru - National Museum Wales. Available online at Wu, J., and Baldwin, I.T. (2010). New insights into plant responses to the attack from insect herbivores. Annual review of genetics 44, 1-24. Zhang, J., Hogenhout, S.A., Nault, L.R., Hoy, C.W., and Miller, S.A. (2004). Molecular and symptom analyses of phytoplasma strains from lettuce reveal a diverse population. Phytopathology 94, 842-849. Zhao, H., Sun, R., Albrecht, U., Padmanabhan, C., Wang, A., Coffey, M.D., Girke, T., Wang, Z., Close, T.J., Roose, M., Yokomi, R.K., Folimonova, S., Vidalakis, G., Rouse, R., Bowman, K.D., and Jin, H. (2013). Small RNA profiling reveals phosphorus deficiency as a contributing factor in symptom expression for citrus huanglongbing disease. Molecular plant 6, 301-310.
摘要: Phytoplasmas are wall-less bacterial plant pathogens. They are restricted to the cytoplasm of phloem sieve cells, and can not be cultured in artificial culture medium. Phytoplasmas are spread by phloem-feeding insects including leafhoppers, planthoppers and psyllids. The disease symptoms caused by phytoplasmas including yellowing leaf, greening flowers, proliferation of stems and phyllody. Those morphological changes are mainly caused by the secreted effectors produced by phytoplasmas. The whole genome of Aster Yellows phytoplasma strain witches’ broom (AY-WB) has been completely sequenced, and 56 candidate effectors has been identified and named secreted AY-WB proteins (SAPs). Among them, SAP11 contains a nuclear localization signal (NLS) for nucleus targeting. SAP11 has been shown to destabilize plant TCP transcription factor, in order to repress the expression of LIPOXYGENASE2, an essential enzyme for jasmonate (JA) biosynthesis. Although SAP11 is a small protein with a molecular weight of approximately 14 kDa, the molecular mechanism in disease developing is still not clear. Here, we found that the purified recombinant SAP11 protein was unstable and could not be crystallized. However, after gel-filtration chromatography analysis, we showed that SAP11 formed a multimeric protein. With RNA-seq analysis, we showed that the expression of Pi deficiency-induced genes such as IPS1, PS2, PHT1;4, IPS2... were triggered by SAP11. Because Pi is an essential element for intracellular pathogens, the regulation of Pi homeostasis may contribute to the growth of phytoplasmas in host cells. In addition, we found that the expression of defense response genes such as PR1, WIN3, PAD4… were also suppressed by SAP11. This data suggests that phytoplasmas repress plant immune responses via secreted SAP11.
植物菌質體(phytoplasma)為一種無細胞壁植物病原菌,寄生在宿主篩管細胞內,且至今尚無法以人工方式培養。菌質體主要藉由葉蟬、飛蝨等媒介昆蟲吸食植物韌皮部組織汁液而傳播。菌質體感染的植株具有發育遲緩、植株矮化、節間縮短、莖葉叢生、葉片捲曲、黃化、花器綠化或葉化等外表型態的改變。目前已知這些病徵的表現和菌質體分泌的作用因子(effector)有關。本實驗研究的材料為翠菊黃萎病(aster yellows)中發現的植物菌質體(Aster Yellows phytoplasma strain Withches’ Broom,AY-WB)。此菌質體的序列已被解序,而其基因組可轉譯出56個分泌性的AY-WB蛋白,簡稱SAPs。SAP11為其中之一,帶有細胞核定位信號(nuclear localization signals,NLSs)且可進入宿主細胞的細胞核,會促進TCP轉錄因子(TCP transcription factors)的降解,進而抑制LOX2的表現,使茉莉酸(jasmonate,JA)生合成量下降。SAP11大小約14 kDa,致病機制尚未清楚。因此本實驗期望能藉不同的實驗方法以更進一步了解SAP11的功能。首先在大腸桿菌中表現重組SAP11蛋白並純化後,藉由分子篩選層析管柱分析可知SAP11會形成聚分子。但因蛋白分子結構不穩定,不易形成結晶。進一步利用次世代定序方式進行SAP11轉殖株與野生種擬南芥的轉錄體分析,發現SAP11的表現會誘發植物產生缺磷反應,其中IPS1、PS2、PHT1;4、IPS2、…等缺磷誘導的基因皆大量表現。由於磷是許多病原菌的必需生存元素,因此調控磷的吸收可能有助於菌質體的繁殖。另一方面,發現表達SAP11會抑制植物產生免疫反應,PR1、WIN3、PAD4、…等水楊酸相關基因有表現量降低或表現時間延後的現象。而這與先前研究指出表現SAP11可提高菌質體昆蟲宿主繁殖後代量之結果相符。因此推測菌質體可能透過分泌SAP11到植物體內降低免疫反應,以提高自身以及傳播之昆蟲宿主繁殖與存活率。
其他識別: U0005-2208201316261000
Appears in Collections:生物科技學研究所



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