Expression of the urease gene of Agaricus bisporus: a tool for studying fruit body formation and post-harvest development

Abstract

Fruit body initials of Agaricus bisporus contain high levels of urea, which decrease in the following developmental stages until stage 4 (harvest) when urea levels increase again. At storage, the high urea content may affect the quality of the mushroom, i.e. by the formation of ammonia from urea through the action of urease (EC 3.5.1.5). Despite the abundance of urea in the edible mushroom A. bisporus, little is known about its physiological role. The urease gene of A. bisporus and its promoter region were identified and cloned. The coding part of the genomic DNA was interrupted by nine introns as confirmed by cDNA analysis. The first full homobasidiomycete urease protein sequence obtained comprised 838 amino acids (molecular mass 90,694 Da, pI 5.8). An alignment with fungal, plant and bacterial ureases revealed a high conservation. The expression of the urease gene, measured by Northern analyses, was studied both during normal development of fruit bodies and during post-harvest senescence. Expression in normal development was significantly up-regulated in developmental stages 5 and 6. During post-harvest senescence, the expression of urease was mainly observed in the stipe tissue; expression decreased on the first day and remained at a basal level through the remaining sampling period.

Genome-wide gene expression patterns in dikaryon of the basidiomycete fungus Pleurotus ostreatus

“…Ureases of bacteria, fungi and higher plants are highly conserved 44 . In higher plants and fungi, the enzyme is encoded by a single gene 45, 46. Thus, our results showed that the poure transcript of DK13 × 3 was from the MK13 poure gene and that RNA editing also occurred (Table 6).…”

GC-MS studies of the chemical composition of two inedible mushrooms of the genus Agaricus

“…This finding once again confirms that higher fungi of the family Agaricaceae accumulate substantial amounts of urea in their fruiting bodies [ 8 ]. It has been suggested that urea acts as an osmotically favourable nitrogen reserve for fungi [ 9 ].…”

Integrated Metabolomics and Transcriptomics Unravel the Metabolic Pathway Variations for Different Sized Beech Mushrooms

“…Exceptionally, some metabolites including urea, glycerol, acetyl-glucosamine, and hepsiziprenols were differentially expressed in the different parts of beech mushrooms. Biochemically, urea is formed by purine degradation in ornithine cycle and functions the translocation of water and nutrients required for fruiting body development [33]. Wagemaker et al (2006) reported the higher urease expression in stipe portion which gradually decrease during the later stages of mushroom development [34].…”