Browsing by Author "Medina, Consuelo"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- ItemA novel Otubain-like cysteine protease gene is preferentially expressed during somatic embryogenesis in Pinus radiata(2008) Aquea Zeballos, José Felipe; Gutiérrez Barros, Florencia; Medina, Consuelo; Arce Johnson, Jorge Patricio
- ItemGenetic and histological studies on the delayed systemic movement of Tobacco Mosaic Virus in Arabidopsis thaliana(2008) Serrano Honeyman, Carolina; González Cruz, Javiera; Jauregui, Francisca; Medina, Consuelo; Mancilla Oyarzo, Pablo Eduardo; Matus Picero, José Tomás; Arce Johnson, Jorge PatricioAbstract Background Viral infections and their spread throughout a plant require numerous interactions between the host and the virus. While new functions of viral proteins involved in these processes have been revealed, current knowledge of host factors involved in the spread of a viral infection is still insufficient. In Arabidopsis thaliana, different ecotypes present varying susceptibilities to Tobacco mosaic virus strain U1 (TMV-U1). The rate of TMV-U1 systemic movement is delayed in ecotype Col-0 when compared with other 13 ecotypes. We followed viral movement through vascular tissue in Col-0 plants by electronic microscopy studies. In addition, the delay in systemic movement of TMV-U1 was genetically studied. Results TMV-U1 reaches apical leaves only after 18 days post rosette inoculation (dpi) in Col-0, whereas it is detected at 9 dpi in the Uk-4 ecotype. Genetic crosses between Col-0 and Uk-4 ecotypes, followed by analysis of viral movement in F1 and F2 populations, revealed that this delayed movement correlates with a recessive, monogenic and nuclear locus. The use of selected polymorphic markers showed that this locus, denoted DSTM1 (Delayed Systemic Tobamovirus Movement 1), is positioned on the large arm of chromosome II. Electron microscopy studies following the virion's route in stems of Col-0 infected plants showed the presence of curved structures, instead of the typical rigid rods of TMV-U1. This was not observed in the case of TMV-U1 infection in Uk-4, where the observed virions have the typical rigid rod morphology. Conclusion The presence of defectively assembled virions observed by electron microscopy in vascular tissue of Col-0 infected plants correlates with a recessive delayed systemic movement trait of TMV-U1 in this ecotype.Abstract Background Viral infections and their spread throughout a plant require numerous interactions between the host and the virus. While new functions of viral proteins involved in these processes have been revealed, current knowledge of host factors involved in the spread of a viral infection is still insufficient. In Arabidopsis thaliana, different ecotypes present varying susceptibilities to Tobacco mosaic virus strain U1 (TMV-U1). The rate of TMV-U1 systemic movement is delayed in ecotype Col-0 when compared with other 13 ecotypes. We followed viral movement through vascular tissue in Col-0 plants by electronic microscopy studies. In addition, the delay in systemic movement of TMV-U1 was genetically studied. Results TMV-U1 reaches apical leaves only after 18 days post rosette inoculation (dpi) in Col-0, whereas it is detected at 9 dpi in the Uk-4 ecotype. Genetic crosses between Col-0 and Uk-4 ecotypes, followed by analysis of viral movement in F1 and F2 populations, revealed that this delayed movement correlates with a recessive, monogenic and nuclear locus. The use of selected polymorphic markers showed that this locus, denoted DSTM1 (Delayed Systemic Tobamovirus Movement 1), is positioned on the large arm of chromosome II. Electron microscopy studies following the virion's route in stems of Col-0 infected plants showed the presence of curved structures, instead of the typical rigid rods of TMV-U1. This was not observed in the case of TMV-U1 infection in Uk-4, where the observed virions have the typical rigid rod morphology. Conclusion The presence of defectively assembled virions observed by electron microscopy in vascular tissue of Col-0 infected plants correlates with a recessive delayed systemic movement trait of TMV-U1 in this ecotype.
- ItemImproved Salinity Tolerance in Carrizo Citrange Rootstock through Overexpression of Glyoxalase System Genes(2015) Alvarez Gerding, Ximena; Cortés Bullemore, Rowena; Medina, Consuelo; Romero Romero, Jesús L.; Inostroza Blancheteau, Claudio; Aquea Zeballos, José Felipe; Arce Johnson, Jorge Patricio
- ItemMethod to produce sterile male flowers and partenocarpic fruits by genetic silencing, associated sequences and vectors containing said sequences (USA, concesión n° 7,994,397)Arce Johnson, Jorge Patricio; Poupin Swinburn, María Josefina; Medina, Consuelo; Cadavid, Agnes; Federici, Fernán
- ItemStructure-function relationship between the tobamovirus TMV-Cg coat protein and the HR-like response(MICROBIOLOGY SOC, 2008) Ehrenfeld, Nicole; Gonzalez, Angel; Canon, Paola; Medina, Consuelo; Perez Acle, Tomas; Arce Johnson, PatricioThe tobamovirus TMV-Cg induces an HR-like response in Nicotiana tabacum cv. Xanthi nn sensitive plants lacking the N or N' resistance genes. This response has been characterized by the appearance of necrotic lesions in the inoculated leaf and viral systemic spread, although the defence pathways are activated in the plant. A previous study demonstrated that the coat protein (CP) of TMV-Cg (CPCg) was the elicitor of this HR-like response. We examined the influence of four specific amino acid substitutions on the structure of CPCg, as well as on the development of the host response. To gain insights into the structural implications of these substitutions, a set of molecular dynamic experiments was performed using comparative models of wild-type and mutant CPCg as well as the CP of the U1 strain of TMV (CPU1), which is not recognized by the plants. A P21L mutation produces severe changes in the three-dimensional structure of CPCg and is more unstable when this subunit is laterally associated in silico. This result may explain the observed incapacity of this mutant to assemble virions. Two other CPCg mutations (R46G and S54K) overcome recognition by the plant and do not induce an HR-like response. A double CPCg mutant P21L-S54K recovered its capacity to form virions and to induce an HR-like response. Our results suggest that the structural integrity of the CP proteins is important for triggering the HIR-like response.