ELICITIN ISOFORMS FROM 7 PHYTOPHTHORA SPECIES - COMPARISON OF THEIR PHYSICOCHEMICAL PROPERTIES AND TOXICITY TO TOBACCO AND OTHER PLANT-SPECIES

The Phytophthora spp. tested produced several elicitin isoforms with different toxicities to tobacco. A general chromatographic procedure is described which can be used to isolate and purify isoforms in large amounts. α Elicitins are acidic molecules with a hydrophobic domain around position 13, while β elicitins are basic with a hydrophilic domain at this position. The molecular weights, isoelectric points, amino acid compositions and N-terminal sequences of these molecules are reported. Their molecular properties, including their unique peculiar chromatographic behaviour, correlated with their level of toxicity to tobacco. Elicitins were shown to have nonspecific toxicity to other solanaceous plant species. The toxicity classification established with tobacco was different for the other plant species. © 1993 Academic Press, Inc.