Fusarium Photoreceptors

Abstract

Light is an important modulating signal in fungi. Fusarium species stand out as research models for their phytopathogenic activity and their complex secondary metabolism. This includes the synthesis of carotenoids, whose induction by light is their best known photoregulated process. In these fungi, light also affects other metabolic pathways and developmental stages, such as the formation of conidia. Photoreceptor proteins are essential elements in signal transduction from light. Fusarium genomes contain genes for at least eight photoreceptors: two flavoproteins, one photolyase, two cryptochromes, two rhodopsins, and one phytochrome. Mutations in five of these genes provide information about their functions in light regulation, in which the flavoprotein WcoA, belonging to the White Collar (WC) family, plays a predominant role. Global transcriptomic techniques have opened new perspectives for the study of photoreceptor functions and have recently been used in Fusarium fujikuroi on a WC protein and a cryptochrome from the DASH family. The data showed that the WC protein participates in the transcriptional control of most of the photoregulated genes, as well as of many genes not regulated by light, while the DASH cryptochrome potentially plays a supporting role in the photoinduction of many genes.

The RNAi Machinery in the Fungus Fusarium fujikuroi Is Not Very Active in Synthetic Medium and Is Related to Transposable Elements

“…Therefore, the RNA extraction method and quality parameters were as previously described. Illumination for 1 h was chosen because it was the maximum response time to the upregulation of photoinduced gene mRNAs previously investigated in both fungi [ 31 , 32 ]. RNAs from two samples of each condition with a size below 150 nt, covering sRNAs and their precursors, were used to construct the sRNA libraries.…”

Three Genes Involved in Different Signaling Pathways, carS, wcoA, and acyA, Participate in the Regulation of Fusarin Biosynthesis in Fusarium fujikuroi

“…This fact highlights the dual role of WcoA as a regulator in the dark and as a photoreceptor responsible for most transcriptional responses to light in Fusarium [ 26 ]. Former data suggest a cooperative participation of WcoA, CryD, and VvdA in the regulation of carotenoid production by light [ 24 ]. The lack of effects of the cryD and vvdA mutations on fusarin synthesis is consistent with the effect of the wcoA gene mutation since both genes are poorly expressed in darkness and are strongly photoinduced via the WC system.…”

“…Of these, the photoreceptor function is carried out by WC1, which contains a LOV (Light, Oxygen, Voltage) domain that binds a flavin molecule as a chromophore. The genome of F. fujikuroi contains genes for several photoreceptors [ 24 ], including an orthologue of WC1 called WcoA. A phenotypic analysis of wcoA -disruption mutants showed that they are affected in the production of different secondary metabolites [ 25 ].…”

Effects of Pulsed Light on Mycelium Growth and Conidiation in Aspergillus oryzae

“…Its recovery rate was lowest following a PBL treatment with a frequency of 32 Hz and an intensity of 20 µmol•m −2 •s −1 [16]. The development and secondary metabolism of Fusarium fujikuroi were regulated by continuous and pulsed light [33][34][35]. Pulsed white light with a frequency of 1 Hz and an illuminance of 25,000 lux had no effect on the development of F. fujikuroi, but the fumonisin yield under PL was half that reported during dark incubation [36].…”