2515Mycelial fungi generate endogenous electrical fields which are associated with polarized tip growth. Here we show that applied electrical fields can dramatically affect the polarity of growth of a variety of filamentous fungi including Neurospora crassa, Aspergillus nidulans, Mucor mucedo, Trichoderma harzianum and Achlya bisexualis. The precise behaviour of each fungus when exposed to an electric field was different; however the sites of germ tube formation and branching, the direction of hyphal extension and the frequency of branching and germination could all be affected. N. crassa and Ach. bisexualis grew and formed branches towards the anode while Asp. nidulans and M . mucedo exhibited tropisms towards the cathode. Galvanotropism of hyphae and branches of T. harzianum was in opposite directions. Germ tube formation from conidia of N. crassa was highly polarized in electrical fields whereas fields of a similar strength had little effect on the polarity of germ tube formation in Asp. nidulans. Hyphae became aligned perpendicularly as they grew longer and as the field strength increased. It is suggested that this perpendicularly orientated extension relieves growth-inhibiting perturbations of the membrane potential in cells which had been aligned parallel to the field. These results are discussed in relation to the hypothesis that the polarity of hyphal growth is under electrical control. I N T R O D U C T I O NExtension of the hyphae and branches of mycelial fungi is restricted to a narrow zone at the extreme apex. In addressing the question of how hyphal growth is polarized, most studies have concentrated on the cytology and enzymology of this region. As a result we have detailed information showing that wall-synthesizing enzymes such as chitin synthase are active only at the apex and that the enzymes and new cell membrane for cell expansion are transferred to the tips in microvesicles (Grove, 1978;Trinci, 1979;Gooday, 1983). However, we are still far from understanding how polarized growth is established and maintained since we know little about how these vesicles are translocated and guided or how polarity is first generated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.