The Effects of Oligosaccharide and Spores from Aspergillus niger on the Defence Responses of Taxus chinensis Leaves In vitro

Spores and oligosaccharide of a strain of Aspergillus niger, which had been isolated from the inner bark of Taxus chinensis, were used to treat T. chinensis leaves. The spores decreased the dry weight and chlorophyll content of the leaves, but increased their malondialdehyde content; oligosaccharide induced similar but more moderate changes. The changes in soluble protein, phenolic content, and peroxidase and phenylalanine ammonia-lyase activity were also analysed. Oligosaccharide significantly increased all these, whereas the spores had contrary effects. Results indicate that oligosaccharide, but not the fungal spores, elicited a defence reaction in T. chinensis. Possible reasons for these different effects on T. chinensis leaves in vitro are discussed.