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 p robe. Two of these genes have been identified and sequenced. The two g enes (Itp1 and Itp2) code for very similar (91.8% identity) proteins, they are separated by approx. 4 kb of DNA and their open reading frame s may be read in the same direction. The gene (Itp1) located upstream has an intron placed in the same position already described for other Itp in maize and rice. Gene Itp2 has no intron. cDNAs corresponding to Itp1 have been identified in a 6-day-old plantlet library, but not fo r Itp2. The results of the comparison between the two sequences indica te the presence of a gap between the two genes in their promoter regio n. LTP seem to be coded for in plants by a small family of genes. At l east in sorghum, two of its components are tightly clustered in the sa me genomic region.