Solar ultraviolet-B radiation, water deficit and ABA sprays induce DNA methylation changes in grapevine cv. Malbec

ALONSO R.; IBAÑEZ V.N.; MARFIL C.F.; BOTTINI R.; MASUELLI R.W.; BERLI F.

Foz de Iguazú

Congreso; XI Congreso Internacional de Biología Molecular de Plantas (IPMB); 2015

SAG, SAIB, SAFV, REDBIO, BA PBL, SBBQ, SBG, SBPC

High altitude vineyards in Mendoza (ca. 1500 m a.s.l.) are characterized for elevated solar ultraviolet B (UV-B) levels that reach up to 0.4 W m-2 in summer and for producing superior enological quality. UV-B and water deficit (D) are environmental factors/signals for which many plant responses are mediated by abscisic acid (ABA), promoting phenols and other volatile compounds production in leaves and berries. These compounds can filter the harmful radiation and act as antioxidant (berry quality indicators). DNA methylation plays a key role in development, contributes to genome stability, and may also respond to external factors supporting adaptation/acclimation to environment. The methylation-sensitive amplification polymorphism (MSAP) procedure is a powerful tool that provides the high resolution of amplified fragment length polymorphism, while the use of isoschizomeric enzymes (MspI/HpaII) allows the evaluation of the methylation status of multiple loci through the genome. Clones of Vitis vinifera cv. Malbec were exposed to contrasting UV-B, D, and ABA treatments during one growing season and MSAP was used for comparing DNA methylation of shoot produced by clones of each treatment in the following year. All treatments induced DNA methylation polymorphism, however, no changes occurred concurrently in all replicates of each treatment, possibly due to stochastic trends. Perception of relatively high solar UV-B produced more unique methylation patterns in correspondence with the phenotypic plasticity observed (higher morpho-physiological changes). To connect the different types of stimuli with particular biological processes, several fragments were gel isolated for sequencing and identifying genome regions with altered 5-methylcytosine patterns.