Cloning of latex-specific and ethylene-inducible promotors from rubber tree

Cloning of glutamine synthetase (GS) and hevein genomic clones was carried out in order to isolate their promotor, GS gene expression is regulated by ethylene in the latex cells. Hevein is exclusively found in the latex cells, as demonstrated by immunolocalization experiments. GS and hevein are therefore good candidates for the cloning of respectively ethylene-inducible and latexspecific promotors. Three different GS genomic clones (GS2, GS3, GS4) were isolated, which all difser from each other and from the GSI isoform available as a cDNA. Analysis of differential gene expression in response to ethylene revealed that GSI was the isogene potentially the most interesting as it was strongly and almost #de novo# induced by ethylene. Four different hevein genomic clones were isolated. Sequencing of their promotor region revealed 2 groupes of sequences, suggesting that hevein is encoded by at least two different genes. Further analysis is on going to identify the most interesting isoform in terms of tissue specificity