Purification and partial characterization of a toxin produced by Ganoderma lucidum, the coconut Ganoderma disease pathogen

An extracellular, hydrophilic, thermostable phytotoxin was purified to homogeneity from culture fluids of Ganoderma lucidum. The phytotoxin was purified by solvent extraction, gel filtration on Sephadex G-75. Toxicity was evaluated with detached leaf sheath and electrolyte leakage bioassays. Purified phytotoxin induced visible symptoms of the disease, when applied to coconut leaves, fronds and roots even at a low concentration. The toxin is a glycoprotein with carbohydrate as the major component. The importance of the carbohydrate moiety for toxic activity was indicated by inactivation of toxic compounds after periodate oxidation. The toxin caused lesions on a number of other monocots and dicots and proved to be non-host specific.