Changes in the DNA methylation induced by UV-B radiation, water restriction and ABA sprays in Malbec vines

Abstract

Gene expression and phenotypic characteristics of plants grown in contrasting environments can be modulated through different epigenetic mechanism such as DNA methylation. This epigenetic mark may act in a dynamic way in response to different environmental conditions were high altitude vines are developed. The experiment hypothesis was that external stimuli/stresses such as high ultraviolet-B (UV-B) radiation levels and/or water restrictions, common in high altitude viticulture, induce changes in the DNA methylation pattern, and these modifications are maintained until the next growing season after the application of the treatments. Contrasting treatments of UV-B, water potential and abscisic acid (ABA) in a cv. Malbec vineyard of Mendoza were applied: i) control; ii) high solar UV-B; iii) water restriction and iv) ABA sprays. After the winter recess, DNA was extracted from the leaves of sprout vine shoots and the methylation patterns were analyzed through MSAP technique (Methylation Sensitive Amplified Polymorphism). The perception of high solar UV-B levels generated more unique methylation patterns. In addition, MSAP fragments associated with each treatment were identified by sequencing. Some sequences showed homologies with transcriptional regulators of plant defense pathways under stress conditions and others to a light-activated photoreceptor protein. The relevance and role of the epigenetic variability found will be discussed in the context of the expansion of wine production towards new geographical areas.