CHITINASES OF THE GRAPEVINE (VITIS-VINIFERA L) - 5 ISOFORMS INDUCED IN LEAVES BY SALICYCLIC ACID ARE CONSTITUTIVELY EXPRESSED IN OTHER TISSUES

Using a colored substrate assay, chitinase activity was detected in va rious grapevine (Vitis vinifera L,) tissues such as winter-resting ste m inter-nodes, roots, berries and leaves. The highest specific activit y was found in the berries and was about 10 times higher than the one extracted from the leaves. Leaf wounding and salicylic acid treatment were able to rise the basal leaf activity by factors of 4.9 and 5.5, r espectively. Up to 13 chitinase isoforms (4 basic and 9 acidic) could be identified in various untreated grapevine tissues by a combination of native IEF and PAGE, Untreated leaves were found to express six (fo ur basic and two acidic) isoforms, Wounding of leaf tissue resulted in the appearance of four new acidic isoforms which have also been ident ified in berry extracts, one of them being present in the roots. Treat ment of wounded leaves with 1 mM salicylic acid provoked a slight furt her increase of these four chitinases and greatly stimulated three of the basic constitutive isoforms. One of the latter was leaf specific w hile the two other ones were present in the stems, roots and berries.