Isolation and characterisation of an invertase cDNA from perennial ryegrass (Lolium perenne).

An invertase (LpFT2) cDNA from perennial ryegrass was isolated and sequenced. Nucleotide sequence analysis revealed an ORF of 2016 bp encoding a protein of 671 amino acids. LpFT2 is 76% identical to sugarcane soluble acid invertase, and contains invertase and fructosyltransferase functional domains. LpFT2 is present as a single copy gene and maps to the distal region of LG6 in perennial ryegrass. The expression pattern analysis of LpFT2 revealed transcript accumulation in seedlings and in mature leaf sheaths. The LpFT2 recombinant protein expressed in yeast showed invertase and fructan exohydrolase-like activities with complete breakdown of sucrose, 1-kestose (DP3), 1,1-kestotetraose (DP4) and 1,1,1-kestopentaose (DP5) into glucose and fructose.