The NADPH oxidase in Volvariella volvacea and its differential expression in response to mycelial ageing and mechanical injury

Abstract

NADPH oxidases are enzymes that have been reported to generate reactive oxygen species (ROS) in animals, plants and many multicellular fungi in response to environmental stresses. Six genes of the NADPH oxidase complex components, including vvnoxa, vvnoxb, vvnoxr, vvbema, vvrac1 and vvcdc24, were identified based on the complete genomic sequence of the edible fungus Volvariella volvacea. The number of vvnoxa, vvrac1, vvbema and vvcdc24 transcripts fluctuated with ageing, and the gene expression patterns of vvnoxa, vvrac1 and vvbema were significantly positively correlated. However, the expression of vvnoxb and vvnoxr showed no significant difference during ageing. In hyphae subjected to mechanical injury stress, both O 2 − and H 2 O 2 concentrations were increased. The expression of vvnoxa, vvrac1, vvbema and vvcdc24 was substantially upregulated, but vvnoxb and vvnoxr showed no response to mechanical injury stress at the transcriptional level. Additionally, the transcription of vvnoxa, vvrac1, vvbema and vvcdc24 could be repressed when the intracellular ROS were eliminated by diphenyleneiodonium (DPI) chloride and reduced glutathione (GSH) treatments. These results indicated a positive feedback loop involving NADPH oxidase and intracellular ROS, which might be the reason for the oxidative burst during injury stress.

Pseudo-Chromosomal Genome Assembly in Combination with Comprehensive Transcriptome Analysis in Agaricus bisporus Strain KMCC00540 Reveals Mechanical Stimulus Responsive Genes Associated with Browning Effect

“…Our transcriptome data on the wounding of responsive genes did not correlate with findings from a previous report ( Figure S3 ). The reason might be that the previous report treated scalpel-induced injury after incubation in a sanitizing solution and then analyzed the expression level after at least 3 days, whereas our transcriptome data concentrated on earlier time points [ 49 ]. Meanwhile, we identified three manganese peroxidase genes, chr03_02290T , chr03_02740T , and chr02_01230T , that were up-regulated in response to a mechanical stimulus ( Figure S4 ).…”