ABSTRACT
KEY MESSAGE: By studying three cv. Malbec clones cultivated in two vineyards with contrasting environmental conditions, we demonstrated that DNA methylation has an important role in the phenotypic plasticity and that epigenetic modulation is clone-dependent. Clonal selection and vegetative propagation determine low genetic variability in grapevine cultivars, although it is common to observe diverse phenotypes. Environmental signals may induce epigenetic changes altering gene expression and phenotype. The range of phenotypes that a genotype expresses in different environments is known as phenotypic plasticity. DNA methylation is the most studied epigenetic mechanism, but only few works evaluated this novel source of variability in grapevines. In the present study, we analyzed the effects on phenotypic traits and epigenome of three Vitis vinifera cv. Malbec clones cultivated in two contrasting vineyards of Mendoza, Argentina. Anonymous genome regions were analyzed using methylation-sensitive amplified polymorphism (MSAP) markers. Clone-dependent phenotypic and epigenetic variability between vineyards were found. The clone that presented the clearer MSAP differentiation between vineyards was selected and analyzed through reduced representation bisulfite sequencing. Twenty-nine differentially methylated regions between vineyards were identified and associated to genes and/or promoters. We discuss about a group of genes related to hormones homeostasis and sensing that could provide a hint of the epigenetic role in the determination of the different phenotypes observed between vineyards and conclude that DNA methylation has an important role in the phenotypic plasticity and that epigenetic modulation is clone-dependent.
Subject(s)
DNA Methylation , Polymorphism, Genetic , Vitis/physiology , Argentina , Epigenesis, Genetic , Farms , Gene-Environment Interaction , Phenotype , Promoter Regions, Genetic , Vitis/geneticsABSTRACT
Environment and crop management shape plant's phenotype. Argentinean high-altitude vineyards are characterized by elevated solar ultraviolet-B radiation (UVB) and water deficit (D) that enhance enological quality for red winemaking. These signals promote phenolics accumulation in leaves and berries, being the responses mediated by abscisic acid (ABA). DNA methylation is an epigenetic mechanism that regulates gene expression and may affect grapevine growth, development and acclimation, since methylation patterns are mitotically heritable. Berry skins low molecular weight polyphenols (LMWP) were characterized in field grown Vitis vinifera L. cv. Malbec plants exposed to contrasting UV-B, D, and ABA treatments during one season. The next season early fruit shoots were epigenetically (methylation-sensitive amplification polymorphism; MSAP) and biochemically (LMWP) characterized. Unstable epigenetic patterns and/or stochastic stress-induced methylation changes were observed. UV-B and D were the treatments that induced greater number of DNA methylation changes respect to Control; and UV-B promoted global hypermethylation of MSAP epiloci. Sequenced MSAP fragments associated with UV-B and ABA showed similarities with transcriptional regulators and ubiquitin ligases proteins activated by light. UV-B was associated with flavonols accumulation in berries and with hydroxycinnamic acids in the next season fruit shoots, suggesting that DNA methylation could regulate the LMWP accumulation and participate in acclimation mechanisms.
Subject(s)
Abscisic Acid/pharmacology , DNA Methylation , Polyphenols/metabolism , Vitis/metabolism , Coumaric Acids/metabolism , DNA Methylation/drug effects , DNA Methylation/radiation effects , Dehydration , Flavonols/metabolism , Fruit/metabolism , Plant Shoots/metabolism , Ultraviolet Rays , Vitis/drug effects , Vitis/physiology , Vitis/radiation effectsABSTRACT
Se estudió la evolución de dos grupos de pacientes con Meningoencefalitis aguda supurada (MEAS). A un grupo se le realizó el tratamiento convencional del Servicio, con Ampicilina y Cloranfenicol. Al otro grupo, Ceftriaxona. El resto del tratamiento de sostén fue similar para ambos grupos. Los grupos fueron comparables en cuanto a procedencia, edad, sexo, tiempo de evolución previo a la internación, etc. Hubo diferencias estadísticamente significativas entre los grupos en cuanto a la presencia de convulsiones, la necesidad de anticomiciales y la etiología. En el grupo tratado con Ampicilina-Cloranfenicol existieron 2 fracasos terapéuticos, en meningitis de etiología meningocóccica, por lo que el estudio fué suspendido en el paciente Nº 38. No existieron fracasos con el tratamiento con Ceftriaxona (AU)
Subject(s)
Humans , Infant , Male , Female , Comparative Study , Meningoencephalitis , Ceftriaxone/therapeutic use , Ampicillin/therapeutic use , Chloramphenicol/therapeutic use , Meningoencephalitis/drug therapy , Meningoencephalitis/etiologyABSTRACT
Se estudió la evolución de dos grupos de pacientes con Meningoencefalitis aguda supurada (MEAS). A un grupo se le realizó el tratamiento convencional del Servicio, con Ampicilina y Cloranfenicol. Al otro grupo, Ceftriaxona. El resto del tratamiento de sostén fue similar para ambos grupos. Los grupos fueron comparables en cuanto a procedencia, edad, sexo, tiempo de evolución previo a la internación, etc. Hubo diferencias estadísticamente significativas entre los grupos en cuanto a la presencia de convulsiones, la necesidad de anticomiciales y la etiología. En el grupo tratado con Ampicilina-Cloranfenicol existieron 2 fracasos terapéuticos, en meningitis de etiología meningocóccica, por lo que el estudio fué suspendido en el paciente Nº 38. No existieron fracasos con el tratamiento con Ceftriaxona