Plant & Animal Genomes XIII Conference Plant & Animal Genomes XIII ConferenceJanuary 15-19, 2005
Town & Country Convention Center
San Diego, CA
Joe A Gallagher , Andrew J Cairns , Phillip Morris
Fructans (polymers of fructose) are the major reserve carbohydrates of temperate grasses. As well as being involved in carbon partitioning, fructans are associated with cold and drought tolerance. To understand and thus manipulate resource allocation in these grasses, it is essential to understand the mechanism of fructan metabolism at both a biochemical and molecular level. It has been shown that soluble (vacuolar) invertases (INV) and fructosyltransferases (FT) function in the vacuole, the primary site of sucrose accumulation. INV activity has been shown to be present in vacuoles prior to sucrose accumulation and fructan synthesis. For fructan synthesis to occur enzymes must be targeted to the appropriate cellular compartments which contain sucrose to initiate polymer synthesis.
We have cloned and characterised the expression profile of a number of invertases and fructosyltransferases from Lolium temulentum. We have found that both enzyme types show similar tissue and cellular distribution, although the induction of FTs gene expression requires carbohydrate accumulation. Data will be presented from biochemical and genetic analysis indicating that invertase, sucrose and fructosyltransferases may not be co-localised in the same sub-cellular compartment.