• Korean Journal Plant Pathology
• /
• v.3 no.3
• /
• pp.198-202
• /
• 1987

Toxic metabolites ('Toxins'), produced by Helminthosporium sativum causing leaf blotch in barley and root rot in barley and wheat were partially purified through C-18 column. The partially purified toxins appeared heat unstable and lipophilic. The responses of toxins to wheat and barley root corresponded with those to lettuce growth with the different concentrations. The determination of the concentration of toxins produced was developed using the dilution end-points. The equation [Y = a log X + b) was obtained from the semi-log­graphy with the linear analysis. The values 'a' and 'b' were discussed with the responses of several plants on the toxin produced by H. sativum.

• The Korean Journal of Mycology
• /
• v.19 no.2
• /
• pp.128-135
• /
• 1991

Diethyl ether soluble toxin produced by H. sativum had the characteristics of helmin­thosporal as based on UV, GC-MS, and chemical analysis, but was not a helminthosporaI. It was speculated that it was a polymer of helminthosporal. It stimulated the productions of reducing sugar in the barly endosperm like gibberellic acid, but acted in the responses on the barley roots and coleoptiles like gibberellic acid. It seemed to be involved in Foliar and Root rot diseases with host specificity, based on the analysis of linear regression.

• The Korean Journal of Mycology
• /
• v.16 no.1
• /
• pp.9-15
• /
• 1988

Two kinds of toxins were demonstrated in the culture filtrate of H. sativum, and were called 'M' and 'D' toxins. The lettuce bioassay indicated that D-toxin caused less root growth inhibition than M-toxin. Chemical analysis indicated that M-toxin was a very unusual small peptide. D-toxin was shown to have chemical characteristics similar to helminthosporal based on ultraviolet, proton nuclear magnetic resonance and mass spectra. D-toxin was composed of at least two isomers.