Inoculantes comerciales en Baja California, México: calidad y capacidad de biocontrol de hongos fitopatógenos

In the present study, the biological quality and cell viability of different microbial inoculants marketed in Baja California, Mexico, was carried out. For this purpose, the antagonistic capacity was determined in triplicate by means of dual confrontation with phytopathogenic fungi, determination of cell viability using the serial dilution technique in culture medium; as well as the review of compliance with the packaging criteria based on the Mexican regulations in the products: Bioben, T-22, Funqui, Agroderma, Bio-Tilis, Enerbac, Fus-Out and Bacillus 1537. The results showed that the products Agroderma, Bacillus 1537 and Fus-Out, no health registration submitted. On the other hand, the viability of the inoculants evaluated by means of the plate count technique, showed values ​​of CFU/g or CFU/mL, lower than those indicated by the labels of the commercial inoculants. The results of antagonism of biological fungi against phytopathogenic fungi: Alternaria alternata, Macrophomina sp., Fusarium solani, and Botrytis sp., showed that only the product formulated based on Bacillus 1537 presented an inhibitory effect greater than 50% on phytopathogens. evaluated. In contrast, the products formulated based on mycoparasitic fungi, showed a lower efficiency of inhibition of phytopathogenic fungi, being the Funqui inoculant, the one that presented the capacity to inhibit their growth by 50%. Finally, Baja California has a wide presence of commercial inoculants; however, its quality and biological efficiency is variable against the pathogens present in the agricultural soils of the region.En el presente estudio se realiza una evaluación de la calidad biológica y viabilidad celular de diferentes inoculantes microbianos comercializados en Baja California, México. Para tal fin, se determina por triplicado la capacidad antagónica mediante la confrontación dual con hongos fitopatógenos, la viabilidad celular usando la técnica de dilución en serie en medio de cultivo; así como la revisión del cumplimiento de los criterios de criterios de rotulación de etiqueta con base a la normativa mexicana en los productos: Bioben, T-22, Funqui, Agroderma, Bio-Tilis, Enerbac, Fus-Out y Bacillus 1537. Los resultados mostraron que los productos Agroderma, Bacillus 1537 y Fus-Out, no presentaron registro sanitario. Por otra parte, la viabilidad de los inoculantes evaluados mediante la técnica de conteo en placa, mostraron valores de UFC/g o UFC/mL, inferiores a los indicados por las etiquetas de los inoculantes comerciales. Los resultados de antagonismos de los productos biológicos contra los hongos fitopatógenos: Alternaria alternata, Macrophomina sp., Fusarium solani, y Botrytis sp., mostraron que solo el producto formulado a base de Bacillus 1537 presentó un efecto inhibitorio mayor del 50% sobre los hongos fitopatógenos evaluados. En contraste, los productos formulados a base de hongos mico-parásitos, mostraron una menor eficiencia de inhibición de hongos fitopatógenos, siendo el inoculante Funqui, el que presentó la capacidad de inhibir el crecimiento de estos en un 50%. Finalmente, Baja California cuenta con una amplia presencia de inoculantes comerciales; no obstante, su calidad y eficiencia biológica es variable contra los agentes patógenos presentes en los suelos agrícolas de la región

Efectos de cadmio en compuestos fenolicos totales y flavonoides de Euglena gracilis

In the present study the production of phenolic acids and flavonoid compounds by E. gracilis exposed to two cadmium concentrations (0.02 and 0.14 mM) was evaluated using high-performance liquid chromatography (HPLC). The results showed that E. gracilis exposed to 0.02 mM Cd+2 increased significantly the total content of phenolic compounds (798.46 ± 12.61 ?g GA/g) and total flavonoids (241.34 ± 47.63 ?g QE/g) with respect to the control (137.34 ± 19.80 ?g QE/g DW and 549.00 ± 8.57 ?g GA/g DW, respectively). However, no significant increase in the total content of phenolic compounds (568.54 ± 17.42 ?g GA/g DW) and total flavonoids (141.11 ± 9.36 ?g QE/g DW) were observed in E. gracilis exposed to 0.14 mM Cd+2. Further research is necessary to determine the specific role of flavonoids in E. gracilis exposed to high concentrations of Cd+2.En el presente estudio la producción de compuestos fenolicos y flavonoides producidos por E. gracilis expuesto a dos concentraciones de cadmio fue evaluado usando cromatografía liquida de alta precisión (HPLC). Los resultados mostraron que 0.02 mM de Cd+2 incrementaba significativamente el contenido total de compuestos fenolicos (798.46 ± 12.61 ?g GA/g) y flavonoides (241.34 ± 47.63 ?g QE/g) con respecto al control (137.34 ± 19.80 ?g QE/g DW y 549.00 ± 8.57 ?g GA/g DW) respectivamente. Sin embargo, incrementos no significativos en el contenido de compuestos fenolicos (568.54 ± 17.42 ?g GA/g DW) y flavonoides totales (141.11 ± 9.36 ?g QE/g DW) fueron observados en E. gracilis expuestas a 0.14 mM de Cd+2. Futuros estudios son necesarios para determinar la función especifica de los flavonoides en E. gracilis expuesto a altas concentraciones de Cd+2

Inhibition of Fusarium solani in transgenic insect-resistant cotton plants treated with silver nanoparticles from Prosopis glandulosa and Pluchea sericea

Abstract The phytosynthesis of nanoparticles is a green chemistry approach that combines nanotechnology and bioactive compounds of plants. The aim of this study was to evaluate the effect of silver nanoparticles (AgNPs) from Prosopis glandulosa and Pluchea sericea, respectively, on the control of Fusarium solani previously inoculated in the rhizosphere of transgenic insect-resistant cotton plants. The results showed that the weekly application of AgNPs from P. glandulosa and P. sericea caused a diminution of fungal propagules in the soil after 30 days of treatment. In this sense, the AgNPs from P. glandulosa were more efficient in the reduction of infection points in the roots of the plants infected with F. solani compared with AgNPs from P. sericea. Additionally, the application of AgNPs from both plants showed a significant increase of optimum quantum yield (Fv/Fm), stomata conductance (gs), and the number of lateral roots in transgenic insect-resistant cotton plants after 30 days of exposure when compared to the control. Based on our results, AgNPs from P. glandulosa and P. sericea could inhibit growth of Fusarium solani. However, more extensive and elaborate studies are needed to explain the different mechanisms that participate in the inhibition of growth of fungus using nanoparticles from these plants

Silver nanoparticles from Prosopis glandulosa and their potential application as biocontrol of Acinetobacter calcoaceticus and Bacillus cereus

In the present study the characterization and properties of silver nanoparticles from Prosopis glandulosa leaf extract (AgNPs) were investigated using UV–Vis spectroscopic techniques, energy dispersive X-ray spectrometers (EDS), zeta potential and dynamic light scattering. The UV–Vis spectroscopic analysis showed the absorbance peaked at 487 nm, which indicated the synthesis of silver nanoparticles. The experimental results showed silver nanoparticles had Z-average diameter of 421 nm with higher stability (−200 mV). The EDS analysis also exhibited presentation of silver element. Additionally, the different concentrations of AgNPs (25, 50, 75 and 100 mg/mL) showed antibacterial activity against Acinetobacter calcoaceticus and Bacillus cereus. Finally, AgNPs from leaf extracts of P. glandulosa may be used as an agent of biocontrol of microorganism of importance medical. However, further studies will be needed to fully understand the antimicrobial activity of silver nanoparticles obtain from P. glandulosa

Changes in the phenylalanine ammonia lyase activity, total phenolic compounds, and flavonoids in Prosopis glandulosa treated with cadmium and copper

ABSTRACT The aim of the present work is to evaluate the changes on the phenylalanine ammonia lyase (PAL) activity, phenolic compounds accumulation and photochemical efficiency in leaves of P. glandulosa treated with Cd2+ (0.001 M) and Cu2+ (0.52 M) concentrations for 96 h under hydroponic conditions. The results showed that only leaves treated with copper had a decrease in photochemical efficiency and leaf epidermal polyphenols in P. glandulosa leaves after 96 h of exposure. On the other hand the reverse-phase HPLC analysis revealed higher levels of phenolic compound (gallic, vanillic and caffeic acids) and flavonoids (rutin and kaempferol-3-O-glucosides) in plant leaves from Cu and Cd-treatments with respect to control plants. Finally, highest increments in PAL activity was observed in extracts of leaves treated with Cu and Cd (about 205 and 284%), respectively, with respect to control plants after 96 h treatment. These suggest that activation of phenylpropanoid pathway represent a source of nonenzymatic antioxidants that protect at P. glandulosa against oxidative stress when exposed to cadmium and copper. Hence future studies are necessary to elucidate the participation of phenylpropanoid pathway in the reduction of metal toxicity in Prosopis species

Bioaccumulation and effect of cadmium in the photosynthetic apparatus of Prosopis juliflora

In the present study Prosopis juliflora plants grown in hydroponics solution were exposed to 50,100 and 1000 μM CdCl2. The cadmium uptake, transport and toxicity on the photosynthetic activities in the plants were measured at 48 h after starting cadmium treatments. The results showed that the concentration of Cd2+ in P. juliflora tended to increase with addition of Cd2+ to hydroponics solution. However, the increase of Cd2+ in roots and leaves varied largely. In this sense, the accumulation of Cd2+ in P. juliflora roots increased significantly in proportion with the addition of this metal. In contrast a relatively low level of Cd2+ transportation index, and bioaccumulation factor were found in P. juliflora at 48 h after of treatments. On the other hand the maximum photochemical efficiency of photosystem II (Fv/Fm) and the activity of photosystem II (Fv/Fo) ratios in P. juliflora leaf treated with Cd2+ not showed significantly changes during the experiment. These results suggested that the photosynthetic apparatus of P. juliflora was not the primary target of the Cd2+ action. Further studies will be focused in understanding the participation of the root system in Prosopis plants with the rhizosphere activation and root adsorption to soil Cd2+ under natural conditions

Changes of photochemical efficiency and epidermal polyphenols content of Prosopis glandulosa and Prosopis juliflora leaves exposed to cadmium and copper

The effect of metals on the photosynthetic activities and epidermal polyphenol content of Prosopis glandulosa and Prosopis juliflora leaves was investigated by the tissue tolerance test. Foliar tissues of Prosopis glandulosa and Prosopis juliflora were incubated with Cd2+ (0.001 M) or Cu2+ (0.52 M) concentrations for 96 h. The results showed that significant reductions (p < 0.05) of photochemical efficiency in P. juliflora leaves were found after 96 h of exposure to 0.52 M Cu2+ compared with Cd-treatments and controls. In contrast, P. glandulosa leaves showed a progressive increase on photochemical efficiency at 72 h after Cu-treatment. The results also showed a significant decrease (p < 0.05) of epidermal polyphenols in P. juliflora leaves after 24 h of exposure to 0.52 M Cu2+ compared with Cd-treatments and control leaves. On the other hand, the values of leaf epidermal polyphenols observed in P. glandulosa exposed to copper and cadmium did not show any difference with respect to control. These findings are very important and suggest that these compounds could be considered as a protection mechanism of P. glandulosa when is treated with these heavy metals. Finally, the results of bioaccumulation showed that the copper concentration in P. glandulosa was higher than the values detected in P. juliflora Nevertheless, the cadmium concentration in foliar tissues of P. juliflora was significantly higher than P. glandulosa after 96 h of exposure to Cu2+ or Cd2+. Therefore, future studies are necessary to elucidate the effects of heavy metals on the biosynthesis of flavonoids and participation of these compounds in the reduction of metal toxicity in Prosopis species