We study the interconversion of sugars in plants. Among them, sorbitol is a key phloem-translocated sugar alcohol in several fruit species, such as apples, pears, nectarines and cherries. We are investigating the feasibility of enzymatically altering the natural conversion of sorbitol to other sugars with the long term biotechnological application of modifying the taste characteristics of several fruits. In Arabidopsis thaliana and grapevine, non-sorbitol translocating species, we have also identified several genes potentially related to sugar alcohol metabolism and we are analysing their function in this plant. For example, reducing the expression of an enzyme involved in sorbitol degradation increases the ability of mutant Arabidopsis to withstand drought stress.
Additionally, for the synthesis and/or modification of glycoproteins and polysaccharides in the lumen of the Golgi apparatus, specific transporter proteins are required for the import of nucleotide-sugars synthesised in the cytosol. We have identified GONST3 and 4 from Arabidopsis and homologues from grapevine, which possess the molecular characteristics of nucleotide-sugar transporters (NSTs) from other organisms which transport GDP-sugars. Our work is focussed on determining the substrate specificity of these NSTs and on analysing their roles in planta.
Techniques in the following areas have been implemented in the laboratory: biochemistry, plant molecular and cellular biology, plant in vitro culture and transformation, and computer modelling of proteins.
Chilean Strawberry Fruit development
Fragaria chiloensis, the Chilean white strawberry, is found between the VII Region and Chiloé (X Region). The highest productivity is concentrated near the Chilean coastal areas of the VII and VIII Regions. It is a native species with great economic potential, and is the mother of the commercial strawberry, Fragaria x ananassa. Fragaria chiloensis is noted for its powerful and pleasant aroma and flavour, but suffers from a short postharvest life. Therefore, our research focuses on determining the molecular bases that will lead to a better understanding of the traits that regulate fruit ripening in this species, in order to improve quality and favour its options in the national and international markets.