THE DYNAMICS OF HYPHAL GROWTH

This account reflects diverse aspects of hyphal growth and development that I have encountered since first becoming interested in fungi. Apical growth is discussed, with particular reference to the phenomena of hyphal maturation and the formation of helical hyphae. It is contrasted with cases of intercalary growth and reversed growth of hyphae. Localization of chitin synthesis at the apex and at other particular sites in the wall is described in detail. It is suggested that chitin microfibrils are synthesized at hyphal tips and at other sites by a transmembrane enzyme complex of several polypeptides allosterically regulated by effector molecules but also perhaps by local physical stress of the membrane. Behaviour of hyphae is discussed with examples of mating zygophores, of contact sensing of surfaces and of responses to applied electric fields.