Relationships between germ-tube growth by Botrytis cinerea and B. fabae and their metabolism of the phytoalexins wyerone, wyerone acid and wyerone epoxide

• Published in: Transactions of the British Mycological Society Vol. 82; no. 3; pp. 571 - 576
• Main Authors: Rossall, S., Mansfield, J.W.
• Format: Journal Article
• Language: English
• Published: London Cambridge University Press 01.05.1984
• Subjects: Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Phytopathology. Animal pests. Plant and forest protection; Systematics. Morphology. Development cycle. Physiology; Botrytis fabae; Fungi; Botrytis cinerea; Growth; Phytoalexin; Germination; Metabolism; Thallophyta
• DOI: 10.1016/S0007-1536(84)80032-7
• ISSN: 0007-1536

Different patterns of germ-tube growth by Botrytis were recorded in the presence of wyerone acid or the methylated phytoalexins wyerone and wyerone epoxide despite germ-tubes reaching the same lengths after 16 h incubation. These differences were associated with the relationships between growth and metabolism of the acid and other phytoalexins. Rapid detoxification of wyerone and wyerone epoxide preceded the onset of germ-tube growth whereas growth has previously been shown to occur without comparable metabolism of wyerone acid. The more rapid metabolism of wyerone and wyerone epoxide was also demonstrated when B. cinerea and B. fabae were exposed to mixtures of the phytoalexins, the acid remaining in cultures when the other phytoalexins had been completely metabolised. In time course experiments the onset of rapid growth by B. fabae occurred when wyerone and the epoxide were present in bathing solutions at levels respectively 1 · 6 and 4 · 3 times those allowing rapid growth of B. cinerea, suggesting that phytoalexin metabolism was not the sole determinant of the differential senstivity of the two species to fungistatic concentrations of the inhibitors.