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Abstract
Comparative studies on germination of conidia of Colletotrichum musae with low and normal iron contents indicated that in addition to lacking the normal requirement for a germination stimulant low-iron conidia germinated substantially faster. Parallel investigations on the iron flux in conidia during germination demonstrated that the presence of germination stimulants did not significantly influence iron uptake or release by conidia. In addition no major intracellular movement of iron between the organelle, wall and soluble fractions of conidia was detected. These findings imply that the action of chelating agents in promoting germination in conidia of C. musae involves the complexing of inhibitory iron at a site within the conidia, so releasing the germination mechanism. Selective accumulation of a germination stimulant (EDTA) within the organelle fraction during induction of germination in iron-replete conidia suggests that the site involved is located in this fraction, possibly on ribosomes. However, the marked differences observed between the relative dimensions of low-iron and iron-replete conidia could implicate the conidial wall as the site of iron complexed by chelating agents involved in stimulation of germination.
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