REDBIO México 2010

Folio: 516
Tipo de presentación: Cartel
Tema: Genómica

Characterization of genes involved in fructan metabolism in Agave tequilana Weber var azul in different developmental stages and plant tissues.

"Cortés-Romero. C.(1)*, Martínez-Hernández, A.(2) and June Simpson (1)
(1) Departamento de Ingeniería Genética, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional Unidad Irapuato, Irapuato 36822, México. (2) Colegio de Postgraduados Campus Campeche, Campeche 24050, México."

RESUMEN (ABSTRACT)
"Agave tequilana Weber var azul is an economically important plant in Mexico, being the only cultivar allowed for tequila production. This cultivar synthesizes large amounts of fructans and fructose polymers are the principal storage product. Fructosyltransferases (FTs) are the enzymes responsible for fructan biosynthesis by transferring fructosyl residues from sucrose or fructan moieties to another sucrose moiety or a growing fructose chain. By screening a collection of EST libraries we have identified six complete cDNA sequences encoding enzymes putatively involved in fructan metabolism including 2 sequences for 1-SST (1-SST1 and 1-SST2), 2 sequences for 6G-FFT (6G-FFT1 and 6G-FFT2) and 2 sequences for invertases involved in sucrose hydrolysis. The object of this work is to characterisize these genes: a. functionally in a heterologous system, b. in terms of expression and c. at the genomic level. The genomic sequences for the 6 genes have been obtained, with most showing a relation of eight exons and seven introns, with a conserved 9 pb miniexon and a variable length second intron. RT-PCR analysis of the identified genes in different tissues of A. tequilana plants at different developmental stages, shows distinct patterns of expression, with FTs expressed mainly in storage tissues and Invertases in photosynthetic tissues. Currently, for functional characterization full length cDNAs for 1-SST2, 6G-FFT1 and a cell wall invertase, were cloned and expressed in the Pichia pastoris system, recombinant proteins were affinity purified and their identity verified by Western blot and partial sequencing."