Purification, characterisation and cDNA cloning of a type 2 (7 kDa) lipid transfer protein from Triticum durum

A type 2 non-specific lipid transfer protein (ns-LTP2) was isolated from wheat (Triticum durum Desf.) endosperm and the primary structure of the protein was fully determined. The protein is basic with a predicted pI of 8.4 and a molecular mass of 6980 Da. It contains 67 amino acids including eight cysteine residues. Oligonucleotide probes covering part of the protein sequence were designed to isolate the corresponding cDNA that contains an open reading frame of 96 amino acids. including a 29 amino acid signal peptide. The T. durian ns-LTP2 showed 37.3-77.6% identity with other ns-LTP2 and is most closely related to the barley and rice sequences. PCR carried out on wheat genomic DNA indicated that the gene encoding this ns-LTP2 does not contain introns. Within developing seeds, the level of ltp7.1 gene transcripts detected by RT-PCR remained broadly similar from the cellular division phase to dry seed. This contrast with the expression pattern of the ltp9.1 gene, the transcripts of which started to accumulate during the filling phase. During germination, the level of ltp7.1 gene transcripts decreased more rapidly than those of the ltp9.1 gene. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.