ISOLATION AND CHARACTERIZATION OF A CDNA CLONE ENCODING AN OSMOTIN-LIKE PROTEIN FROM ARABIDOPSIS-THALIANA

A phage library of cDNA from Arabidopsis thaliana has been screened wi th oligodeoxyribonucleotides designed from regions of high homology fo und in tobacco osmotin and other osmotin-like proteins. One of the sel ected clones, Atosm34, presents a 734 bp open reading frame encoding a polypeptide of 244 amino acids, including the putative N-terminal sig nal and C-terminal propeptide sequences. Comparative alignment reveals extensive homologies to osmotin and the osmotin-like proteins found i n Solanaceae, and also to a related polypeptide found in soybean. Geno mic hybridization suggests that the cDNA obtained here corresponds to a single copy gene, and RNA blot analysis showed that the level of exp ression is highest in old leaves. (C) 1997 Elsevier Science B.V.