A plant virus causes symptoms through the deployment of a host-mimicking protein domain to attract the insect vector.

During compatible plant-virus interactions, viruses can interfere with the normal developmental program of their hosts, leading to the appearance of phenotypes that we usually identify as ‘’symptoms of infection’’ (leaf curling and yellowing, stunting, dwarfism, necrosis). Despite their relevance, the molecular mechanisms underlying symptom induction and their biological meaning, if any, remain poorly understood. By using tomato yellow leaf curl virus (TYLCV, Geminivirus) as model, we have isolated C4 as the main protein responsible for the induction of TYLCV-associated symptoms in tomato. C4, by mimicking a host protein domain, the Conserved C-termini in LAZY1 protein family (CCL) domain, physically interacts with the RCC1-like domain-containing plant proteins (RLDs). By interacting with the RLDs through the CCL-like domain, C4 displaces one endogenous interactor, LAZY (LZY), interfering with RLD functions in processes such as auxin signaling and endomembrane trafficking, which correlates with the manifestation of symptoms. Surprisingly, we observed that appearance of C4-mediated symptoms in tomato plants plays no major role in viral replication nor movement, but they serve as attractants for the insect vector, the whitefly Bemisia tabaci, which preferentially feeds on tomato plants exhibiting strong symptoms of viral infection. These results suggest that, during plant-virus co-evolution, symptoms may have appeared as a strategy to promote viral transmission by the insect vector, at least in some specific plant-virus-vector pathosystems.Work in RLD’s lab is partially funded by the Excellence Strategy of the German Federal and State Governments, the ERC-COG GemOmics (101044142), the DeutscheForschungsgemeinschaft (DFG, German Research foundation) (project numbers LO 2314/1-1 and SBF 1101/3, C08), and a Royal Society Newton Advance grant (NA140481 – NAF\R2\180857). EA is the recipient of a Marie Skłodowska-Curie Grant from the European Union’s Horizon 2020 Research and Innovation Program (Grant 896910-GeminiDECODER). Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Identificación de factores de virulencia determinantes de necrosis en infecciones compatibles planta-virus y su papel en la respuesta a estreses abióticos asociados al cambio climático

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, Departamento de Bioquímica y Biología Molecular I, leída el 21-06-2017Las infecciones múltiples de virus en un hospedador compatible son habituales en la naturaleza; de hecho, constituyen más bien la norma. Cuando más de un virus se establece en un mismo hospedador, pueden tener lugar una serie de interacciones que, en su mayoría, presentan implicaciones epidemiológicas y patológicas pobremente caracterizadas, frecuentemente imprevisibles, y ampliamente dependiente de factores ambientales. Entre estos factores ambientales se encuentran precisamente la [CO2] en la atmósfera, la T y la disponibilidad de agua, cuyos valores se encuentran en permanente cambio como consecuencia de la actividad humana y del calentamiento global asociado...This PhD Thesis exposes and discusses research work consisting of the following topics: i) the viral factor responsible for systemic necrosis elicited during viral synergistic interactions between PVX (Potato virus X, a potexvirus) and viruses belonging to Potyvirus genus, and ii) the effect of environmental stresses associated to climate change, such as high levels of CO2 in the atmosphere ([CO2]), elevated temperatures (T) or drought, on the outcome of compatible plant-virus interactions, on single or mixed infections, with viruses taking part in the PVX-potyvirus interaction mentioned above, or chimeric viruses deriving from them.Mixed infections in a compatible host are common phenomena in nature; in fact, they are the rule rather than the exception. A number of different viral interactions can take place when several viruses are established in the same host. These interactions have epidemiological and pathological implications that are poorly characterized, frequently unpredictable, and largely influenced by environmental factors. Among these environmental factors are [CO2] in the atmosphere, T and water availability, whose values are continuously being modified as a result of human activities and the associated global warming...Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEunpu