A pair of genes coding for lipid-transfer proteins in Sorghum vulgare

Approximately five genes coding for lipid-transfer proteins (LTP) can be detected in Sorghum vulgare by DNA blots using a specific genomic probe. Two of these genes have been identified and sequenced. The two genes (ltp1 and ltp2) code for very similar (91.8% identity) proteins, they are separated by approx. 4 kb of DNA and their open reading frames may be read in the same direction. The gene (ltp1) located upstream has an intron placed in the same position already described for other ltp in maize and rice. Gene ltp2 has no intron. cDNAs corresponding to ltp1 have been identified in a 6-day-old plantlet library, but not for ltp2. The results of the comparison between the two sequences indicate the presence of a gap between the two genes in their promoter region. LTP seem to be coded for in plants by a small family of genes. At least in sorghum, two of its components are tightly clustered in the same genomic region.