ABSTRACT
Tomato is one of the most important fruits worldwide. It is widely consumed due to its sensory and nutritional attributes. However, like many other industrial crops, it is affected by biotic and abiotic stress factors, reducing its metabolic and physiological processes. Tomato plants possess different mechanisms of stress responses in which hormones have a pivotal role. They are responsible for a complex signaling network, where the antioxidant system (enzymatic and non-enzymatic antioxidants) is crucial for avoiding the excessive damage caused by stress factors. In this sense, it seems that hormones such as ethylene, auxins, brassinosteroids, and salicylic, jasmonic, abscisic, and gibberellic acids, play important roles in increasing antioxidant system and reducing oxidative damage caused by different stressors. Although several studies have been conducted on the stress factors, hormones, and primary metabolites of tomato plants, the effect of endogenous and/or exogenous hormones on the secondary metabolism is still poorly studied, which is paramount for tomato growing management and secondary metabolites production. Thus, this review offers an updated overview of both endogenous biosynthesis and exogenous hormone application in the antioxidant system of tomato plants as a response to biotic and abiotic stress factors.
ABSTRACT
An Acinetobacter calcoaceticus UTMR2 strain was evaluated in tomatillo plants (Physalis ixocarpa Brot.) using a factorial design with different potassium doses (100, 75, 50 and 0% of the recommended dose). In addition to the agronomic parameters, an analysis of the physicochemical, antioxidant, and metabolomic properties of the fruit was performed. The application of the inoculant affected several parameters of the plant (chlorophyll, weight, and contents of several mineral elements) as well as of the fruit (yield, maturity index, FRAP antioxidant capacity, and contents of protein, fiber, and fat). A multivariate analysis was performed by means of a PCA and a heatmap, indicating that the inoculant induced a strong modulating activity in tomatillo plants for the evaluated parameters, with a remarkable effect at low K doses (0 and 50%). The inoculated treatment at 75% of the K dose resulted in similar plant and fruit characteristics to the fully fertilized control. On the other hand, the biofertilized treatment with no K addition resulted in the highest values in the plant and fruit parameters. In addition, from the metabolomics analysis of the fruits at 75% of the K dose, the up-regulation of 4,4â³-bis(N-feruloyl)serotonin, salvianolic acid K, and chlorogenic acid was observed, which may have a role in anti-senescence and resistance mechanisms. In conclusion, the rhizobacterial strain had a positive effect on plant growth, nutritional quality, bioactive compounds, and antioxidant activity of tomatillo fruits at reduced doses of K fertilizer, which gives support for its consideration as an effective biofertilizer strain.
ABSTRACT
RESUMEN Objetivo Evaluar el efecto de la aplicación de métodos combinados para incrementar la vida en anaquel de agua de coco. Métodos El agua de coco fue obtenida de comercios no establecidos en la Ciudad de Puebla, México. El agua de coco fue tratada con luz ultravioleta-C, vainillina o cinamaldehído y almacenada a 5 y 22°C. Se evaluó el efecto de estas tecnologías sobre el crecimiento microbiano de bacterias mesófilas aerobias, mohos y levaduras. Resultados El tratamiento con luz ultravioleta-C redujo la carga microbiana de bacterias mesófilas aerobias y mohos y levaduras en 3,2 y 2,9 ciclos logarítmicos, respectivamente. Durante el almacenamiento del agua de coco, la combinación de luz ultravioleta-C, cinamaldehído y baja temperatura mantuvo una carga microbiana en ambos grupos de microorganismos por debajo de 10 UFC/mL, durante 30 días. Conclusión La aplicación de métodos combinados puede ser una alternativa a bajo costo para la conservación de agua de coco.
ABSTRACT Objective To evaluate the effect of combined methods for increasing the shelf life of coconut water. Methods Coconut water was obtained from non-established commerce of Puebla City, Mexico. Coconut water was treated with ultraviolet-C light, vanillin or cinnamaldehyde, and stored at 5 and 22°C. The effect of combined methods was evaluated in the growth of aerobic mesophiles and molds plus yeasts. Results Ultraviolet-C light treatment reduced the microbial load of aerobic mesophiles and molds plus yeast in 3,2 and 2,9 log cycles, respectively. In stored coconut water, the combination of ultraviolet-C light, cinnamaldehyde and low temperature maintained the microbial load in both groups of microorganisms under 10 CFU/mL for 30 days. Conclusion Combined methods may be an alternative at a low cost for the conservation of coconut water.
ABSTRACT
The aim of this study was to evaluate the antifungal activity (in vitro) of thymol and carvacrol alone or in mixtures against Fusarium verticillioides and Rhizopus stolonifer, and to obtain primary growth models. Minimal inhibitory concentration (MIC) was evaluated with fungal radial growth with thymol or carvacrol concentrations (0-1600mg/l). Mixtures were evaluated using concentrations below MIC values. Radial growth curves were described by the modified Gompertz equation. MIC values of carvacrol were 200mg/l for both fungi. Meanwhile, MIC values of thymol were between 500 and 400mg/l for F. verticillioides and R. stolonifer, respectively. A synergistic effect below MIC concentrations for carvacrol (100mg/l) and thymol (100-375mg/l) was observed. Significant differences (p<0.05) between the Gompertz parameters for the antimicrobial concentrations and their tested mixtures established an inverse relationship between antimicrobial concentration and mycelial development of both fungi. Modified Gompertz parameters can be useful to determine fungistatic concentrations.
