Influence of light on growth, conidiation and fumonisin production by Fusarium uerticillioides

Light is a very important signal for fungi since it influences many different physiological responses. We analyzed the influence of light of varying wavelength and intensity on growth, conidiation and biosynthesis of fumonisin B-1 (FB1), B-2 (FB2), and B-3 (FB3) by Fusarium verticillioides ITEM 10027. Wavelengths across the visible spectrum, from red (627 nm) to blue (470-455 nm), stimulated the growth and increased the fumonisin production, by up to 150 % over dark incubation. If the intensity of the 455 nm blue light increased from 200 to 1700 lx, the fumonisin biosynthesis decreased. Incubation under a short wave blue light (390 nm) showed reduced fungal growth and fumonisin production by up to 85 %. White pulsing light had no effect on growth but reduced fumonisin production to half of what observed during dark incubation. Real time reverse transcriptase (RT)-PCR was used to measure the expression level of Fum1, Fum21 and F nu VE1 transcripts, which encode proteins involved in fumonisin biosynthesis. There was a significant correlation between gene expression and fumonisin production. (C) 2011 British Mycological Society. Published by Elsevier Ltd. All rights reserved.