ABSTRACT
Because the mycelium penetrate into the substratum for absorbing nutrients, where little light penetrates, there has been a tendency to think that-unlike in plants-light is not essential for the growth and development of fungi. Indeed, even when fungi and green plants share a platform (as in university botany departments), it is understandable if in the past the fungi were discriminated against on this basis. The data in Table 13.1 show that just a brief šash of light is sufœcient to evoke a development response. Analysis of genome sequences of Neurospora crassa and Aspergillus nidulans led to unexpected identiœcation of homologues of plant photoresponse proteins-the phytochrome and cryptochrome-which sparked an interest in the role of light in the development and behavior of fungi. The increasing awareness that light regulates metabolic pathways in fungi (Tisch and Schmoll, 2010) should encourage investigators to report environmental conditions for greater reproducibility of results. Perhaps the lack of realization that light inšuences fungal biochemistry and physiology led to ignoring the need for controlling illumination, resulting in irreproducible results, and to the fungi being dubbed as “a mutable and treacherous tribe.” Biosynthesis of penicillin in certain fungi is inhibited by light. Cellulase gene expression in Trichoderma is reported to be stimulated by light.
