PH AND CA2+ DEPENDENT GALVANOTROPISM OF FILAMENTOUS FUNGI - IMPLICATIONS AND MECHANISMS
PH AND CA2+ DEPENDENT GALVANOTROPISM OF FILAMENTOUS FUNGI - IMPLICATIONS AND MECHANISMS
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DOI：
10.1016/s0953-7562(09)80458-9
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发表时间：
1994-03-01
影响因子：
--
通讯作者：
GOW, NAR
中科院分区：
文献类型：
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作者：
LEVER, MC;ROBERTSON, BEM;GOW, NAR
Galvanotropism is the directional growth response of organisms to externally applied electrical fields. The galvanotropic response of hyphae of Aspergillus nidulans, Neurospora crassa and Coprinus cinereus was pH-dependent. Alignment of hyphae of N. crassa towards the anode increased with increasing external pH. In contrast, hyphae of A, nidulans and C. cinereus became increasingly cathodotropic in media of more alkaline pH. Galvanotropism of each fungus had an isoelectric point at which the hyphae were unresponsive to the field. It is suggested that the electrical field changes the distribution of certain proteins in the cell membrane thereby inducing polarity. External pH may influence galvanotropism by altering the net charge on such proteins.The anodotropic response of Aspergillus fumigatus was dependent on exogenous calcium ions, decreasing in media with low external Ca2+. This suggests that Ca2+-channels may be involved in the regulation of galvanotropism. A model is presented that accounts for the various anodotropic, cathodotropic movements of different fungi and the PH and Ca2+-dependency of their responses to electrical fields. This involves an interplay between (i) the electrombilization of proteins in the cell membrane and (ii) electrical field-induced perturbation of calcium ion transport in the determination of the extent and direction of galvanotropism.
