Isolation and characterisation of a sucrose : sucrose 1-fructosyltransferase gene from perennial ryegrass (Lolium perenne)

A sucrose : sucrose 1-fructosyltransferase (1-SST) gene and cDNA (Lp1-SST) from perennial ryegrass (Lolium perenne) were isolated. The Lp1-SST gene was fully sequenced and shown to contain three exons and two introns. Nucleotide sequence analysis of the 4824 bp Lp1-SST genomic sequence revealed 1618 bp of 5′ UTR and an open reading frame of 1962 bp encoding a protein of 653 amino acids. Lp1-SST is 95 percnt; identical to the tall fescue 1-SST and contains plant fructosyltransferase functional domains. Lp1-SST corresponds to a single copy gene in perennial ryegrass, and is expressed in young leaf bases and mature leaf sheaths. The recombinant Lp1-SST protein from corresponding cDNA expression in Pichia pastoris showed 1-SST activity.