RESUMEN
In this study, 0, 0.5, 1, 1.5, 2, 4, 6 and 8 mg·kg-1 of cadmium were added to the cultivation materials. In order to study the effects of different concentrations of Cd stress on J1 and J77, the contents of antioxidant enzymes, proline and malondialdehyde, Cd content, agronomic traits and yield of fruiting bodies of Agaricus brasiliensis were determined, and the nutritional components such as polysaccharide, triterpene, protein, total sugar and total amino acid were determined. The results showed that the physiological indexes of strain J1 and J77 changed regularly under different concentrations of Cd stress. J1 was a high absorption and low tolerance variety, while J77 was a low absorption and high tolerance variety. Low concentration of Cd promoted the growth of strain J1, and higher concentration of Cd promoted the growth of strain J77. The contents of protein and total amino acids in the two strains changed greatly, followed by polysaccharides, which indicated that Cd stress had the greatest impact on the three nutrients, and other nutrients were not sensitive to Cd stress.
Asunto(s)
Agaricus/efectos de los fármacos , Cadmio/efectos adversos , Agaricus/química , Agaricus/crecimiento & desarrollo , Agaricus/fisiología , Calidad de los Alimentos , Malondialdehído/metabolismo , Prolina/metabolismo , Estrés Fisiológico/efectos de los fármacosRESUMEN
Cadmium (Cd) is a toxic metal occurring in the environment naturally. Almond mushroom (Agaricus brasiliensis) is a well-known cultivated edible and medicinal mushroom. In the past few decades, Cd accumulation in A.brasiliensis has received increasing attention. However, the molecular mechanisms of Cd-accumulation in A. brasiliensis are still unclear. In this paper, a comparative transcriptome of two A.brasiliensis strains with contrasting Cd accumulation and tolerance was performed to identify Cd-responsive genes possibly responsible for low Cd-accumulation and high Cd-tolerance. Using low Cd-accumulating and Cd-tolerant (J77) and high Cd-accumulating and Cd-sensitive (J1) A.brasiliensis strains, we investigated 0, 2 and 5 mg L-1 Cd-effects on mycelium growth, Cd-accumulation and transcriptome revealed by RNA-Seq. A total of 57,884 unigenes were obtained. Far less Cd-responsive genes were identified in J77 mycelia than those in J1 mycelia (e.g., ABC transporters, ZIP Zn transporter, Glutathione S-transferase and Cation efflux (CE) family). The higher Cd-accumulation in J1 mycelia might be due to Cd-induced upregulation of ZIP Zn transporter. Cd impaired cell wall, cell cycle, DNA replication and repair, thus decreasing J1 mycelium growth. Cd-stimulated production of sulfur-containing compounds, polysaccharides, organic acids, trehalose, ATP and NADPH, and sequestration of Cd might be adaptive responses of J1 mycelia to the increased Cd-accumulation. DNA replication and repair had better stability under 2 mg L-1 Cd, but greater positive modifications under 5 mg L-1 Cd. Better stability of DNA replication and repair, better cell wall and cell cycle stability might account for the higher Cd-tolerance of J77 mycelia. Our findings provide a comprehensive set of DEGs influenced by Cd stress; and shed light on molecular mechanism of A.brasiliensis Cd accumulation and Cd tolerance.
Asunto(s)
Agaricus/metabolismo , Cadmio/metabolismo , Transcriptoma , Transportadoras de Casetes de Unión a ATP/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Agaricus/efectos de los fármacos , Agaricus/genética , Cadmio/toxicidad , Reparación del ADN/efectos de los fármacos , Replicación del ADN/efectos de los fármacos , Tolerancia a Medicamentos , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Micelio/química , Micelio/efectos de los fármacos , Micelio/crecimiento & desarrollo , Polisacáridos/metabolismo , ARN de Hongos/química , ARN de Hongos/metabolismo , RNA-SeqRESUMEN
The use of fungicides is common in mushroom cultivation, but no study was carried out applying reduced doses of fungicides in order to increase yield, taking account the hormesis effect. The aim of this manuscript was to verify the effects of different concentrations of fungicides to stimulate the productivity of different strains of Agaricus bisporus. Two stages were developed, an in vitro study to define the best concentration to be applied in the second experiment an agronomic study, which consisted of the application of the selected fungicides, in their respective concentrations, in an experiment carried out in the mushroom chamber. Clearly, the result of the hormesis effect on mushroom cultivation can be verified. The results obtained in the 1st stage of the study (in vitro) were not always reproduced in the 2nd stage of the study (in vivo). The kresoxim methyl active ingredient may be an important chemical agent, while strain ABI 15/01 may be an extremely important biological agent to increase yield in the study of hormesis effects.
Asunto(s)
Agaricus/crecimiento & desarrollo , Fungicidas Industriales/administración & dosificación , Estrobilurinas/administración & dosificación , Agaricus/efectos de los fármacos , Producción de Cultivos , Relación Dosis-Respuesta a Droga , Fungicidas Industriales/farmacología , Hormesis , Estrobilurinas/farmacologíaRESUMEN
Laccases are polyphenol oxidases produced by many fungi and have many applications in textile, food and beverage, and pulp and paper industries. Laccase production can be induced using aromatic or phenolic compounds that mostly affect the transcription of laccase-encoding genes. In this study, we analyzed laccase and biomass production by Agaricus blazei in the presence of different concentrations of nitrogen, copper, and inducers such as pyrogallol, veratryl alcohol, xylidine, vanillin, guaiacol, and ethanol. Laccase production by A. blazei U2-4 reached 43.8 U/mL in the presence of 2.8 g/L nitrogen and 150 µM copper. However, addition of copper to the cultivation medium decreased biomass production. Different compounds differentially induced laccase production by A. blazei. Moreover, different concentrations of these inducers exerted different effects on laccase activity. Ethanol (1.0 mM), guaiacol (0.5 mM), and vanillin (0.5 mM) were the best inducers and increased laccase activity by 120% (A. blazei U2-2), 30% (A. blazei U2-3), and 9% (A. blazei U2-4), respectively. In contrast, pyrogallol and xylidine decreased laccase activity but increased biomass production.
Asunto(s)
Agaricus/efectos de los fármacos , Agaricus/metabolismo , Lacasa/biosíntesis , Biomasa , Cobre/metabolismo , Activación Enzimática , Nitrógeno/metabolismo , Compuestos Orgánicos/farmacologíaRESUMEN
This work had the dual objective of selecting a substrate for rapid mycelial growth of Scytalidium thermophilum and then comparing the growth and production of a brown variety of Agaricus bisporus on substrate non-colonized and colonized with S. thermophilum. Mycelial growth of S. thermophilum at 45 degrees C was significantly greater on potato dextrose yeast extract agar (0.58 mm/h) as compared to malt extract glucose agar (0.24 mm/h) and yeast extract glucose agar (0.44 mm/h). On cereal grain, S. thermophilum grew significantly faster on rice (0.31 mm/h) compared to sorghum (0.22 mm/h) and millet (0.18 mm/h). It also grew faster on Pangola grass (0.49 mm/h) compared to corncobs (0.30 mm/h) and sawdust (0.18 mm/h). Colonization of Pangola grass with S. thermophilum was influenced by the addition of calcium salts in the form of gypsum, hydrated lime and ground limestone. For production of A. bisporus, biological efficiency (BE) on pasteurized Pangola grass pre-colonized by S. thermophilum for 4 days at 45 degrees C was more than twice (26.4%) that on grass non-colonized by S. thermophilum (11.0%). The addition of 2% hydrated lime to Pangola grass prior to colonization by S. thermophilum resulted in an additional doubling of BE of mushroom production (48.1%). These results show the possibility of developing a non-composted substrate method for producing A. bisporus without autoclaving the substrate.