Self inhibition of the Agaricus bisporus Spore by CO2 and/or γ‐Glulaminyl‐4‐hydroxybenzene and γ‐Gtutaminyl‐3,4‐benzoquinone: A Biochemical Analysis

Abstract

Chemical and enzymological analyses have been carried out to study the mode of action of CO2, in inhibiting germination in Agaricus bisporus and to test the suggestion (Vogel and Weaver, 1972. Exp. Cell Res. 75: 95, Vogel et at, 1974. Am. J. Pathol. 76: 165) that γ‐glutaminyl‐4‐hydroxybenzene (GHB) and/or γ‐glutaminyl‐3,4‐benzoquinone (GBQ) would inhibit the succinate dehydrogenase (SDH) in the mushroom spore and thus represent the causal agent(s) of its dormancy. Evidence is presented that the impairment of SDH is brought about by Ihe CO, fixation product oxaloacelate which is formed in the pyruvate carboxylase reaction, and a mechanism is proposed for the release of the SDH inhibition when activating the spores. These are almost devoid of GHB, whereas fruit bodies of all developmental stages contain considerable amounts of the phenol. GBQ is absent in the spore, and its occurrence in mushroom fruit body extracts appears to be an artifact of extraction. Apart from these analytical results, theoretical reasons are given that vouch against the involvement of the phenolics in the inhibition of SDH in vivo.

Effects of washing on polyphenols and polyphenol oxidase in commercial mushrooms (Agaricus bisporus)

“…The mushrooms were packed with frozen gel packs in insulated containers and shipped to our laboratory within 24 h by air express. y-L-Glutaminyl-4-hydroxybenzene (GHB) and y-L-glutaminyl-3,4dihydroxybenzene (GDHB), used as analytical standards, were extracted from mushroom gill tissue, following the procedure of Rast et al (1979), and identified by UV and 'H NMR spectroscopy (XH NMR spectra were obtained with a JEOL GX-400 instrument with D2O). l-DOPA and tyrosine were obtained from Sigma Chemical Co. All other chemicals were of reagent grade.…”

“…Isolation and Quantitation of GHB, Tyrosine, GDHB, and l-DOPA from Mushrooms. Apart from minor modifications, the isolation and quantitation of major substrates of PPO in mushroom were according to the procedures of Rast et al (1979) and Speroni and Beelman (1982), respectively.…”

Physiology and Biochemistry of Fungal Sporulation

“…Evidence suggests that CO2 indirectly inhibits succinic dehydrogenase activity, inducing a meta bolic block and maintaining spore dormancy (75). The metabolic block and hence, dormancy, are relieved by the addition of isovaleric acid.…”

Purpling Reaction of Sinapic Acid Model Systems Containing L-DOPA and Mushroom Tyrosinase

“…Oxidation of GHB by Tyrosinase in the Presence of Sinapic Acid. GHB, the most predominant phenolic substrate of tyrosinase in mushroom sporophores, is wellknown to have important roles in tissue browning and melanin formation, as well as in the induction of spore dormancy in A. bisporus (Oka et al, 1981;Rast et al, 1979; Stussi and Rast, 1981;Vogel and Weaver, 1972).…”

“…Mushroom tyrosinase (EC 1.14.18.1; monophenol, dihydroxyphenylalanine:oxygen oxidoreductase), l-DOPA, pyrocatechol, and various phenolic acids except the three phenolic acids specified below were obtained from Sigma Chemical Co. (St. Louis, MO). 7-L-Glutaminyl-4-hydroxybenzene (GHB) was extracted from the gill tissue of mushroom following the procedure of Rast et al (1979) and identified by UV and NMR spectroscopy (1H NMR spectra were obtained with a JEOL GX-400 instrument with D20). Vanillic, gentisic, and sinapic acids as well as sodium periodate were purchased from Aldrich Chemical Co. (Milwaukee, WI).…”