Biostimulants are materials that when applied in small amounts are capable of promoting plant growth. Nanoparticles (NPs) and nanomaterials (NMs) can be considered as biostimulants since, in specific ranges of concentration, generally in small levels, they increase plant growth. Pristine NPs and NMs have a high density of surface charges capable of unspecific interactions with the surface charges of the cell walls and membranes of plant cells. In the same way, functionalized NPs and NMs, and the NPs and NMs with a corona formed after the exposition to natural fluids such as water, soil solution, or the interior of organisms, present a high density of surface charges that interact with specific charged groups in cell surfaces. The magnitude of the interaction will depend on the materials adhered to the corona, but high-density charges located in a small volume cause an intense interaction capable of disturbing the density of surface charges of cell walls and membranes. The electrostatic disturbance can have an impact on the electrical potentials of the outer and inner surfaces, as well as on the transmembrane electrical potential, modifying the activity of the integral proteins of the membranes. The extension of the cellular response can range from biostimulation to cell death and will depend on the concentration, size, and the characteristics of the corona.

Biostimulants are materials that when applied in small amounts are capable of promoting plant growth. Nanoparticles (NPs) and nanomaterials (NMs) can be considered as biostimulants since, in specific ranges of concentration, generally in small levels, they increase the plant growth. Pristine NPs and NMS have a high density of surface charges capable of unspecific interactions with the surface charges of the cell walls and membranes of plant cells. In the same way, the functionalized NPs and NMS, and the NPs and NMs with a corona formed after the exposition to natural fluids such as water, soil solution, or the interior of organisms, presents a high density of surface charges that interact with specific charged groups in cell surfaces. The magnitude of the interaction will depend on the materials adhered to the corona, but the high-density charges located in a small volume causes an intense interaction capable of disturbing the density of surface charges of cell walls and membranes. The electrostatic disturbance can have an impact on the electrical potentials of the outer and inner surfaces, as well as on the transmembrane electrical potential, modifying the activity of the integral proteins of the membranes. The extension of the cellular response can range from biostimulation to cell death and will depend on the concentration, size, and the characteristics of the corona.

Non-linear systems, such as biological systems, can be simulated by artificial neural network (ANN) techniques. This research aims to use ANN to simulate the accumulated aerial dry matter (leaf, stem, and fruit) and fresh fruit yield of a tomato crop. Two feed-forward backpropagation ANNs, with three hidden layers, were trained and validated by the Levenberg–Marquardt algorithm for weights and bias adjusted. The input layer consisted of the leaf area, plant height, fruit number, dry matter of leaves, stems and fruits, and the growth degree-days at 136 days after transplanting (DAT); these were obtained from a tomato crop, a hybrid, EL CID F1, with indeterminate growth habits, grown with a mixture of peat moss and perlite 1:1 (v/v) (substrate) and calcareous soil (soil). Based on the experimentation of the ANNs with one, two and three hidden layers, with MSE values less than 1.55, 0.94 and 0.49, respectively, the ANN with three hidden layers was chosen. The 7-10-7-5-2 and 7-10-8-5-2 topologies showed the best performance for the substrate (R = 0.97, MSE = 0.107, error = 12.06%) and soil (R = 0.94, MSE = 0.049, error = 13.65%), respectively. These topologies correctly simulated the aerial dry matter and the fresh fruit yield of the studied tomato crop.

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ResumenSe presenta una revisión acerca de la biofabricación de nanopartículas (NPs) de metales usando extractos vegetales, cultivos celulares de órganos o bien plantas vivas. Se describen los dos métodos de biofabricación verde de nanopartículas: el proceso bioquímico con extractos y el proceso biológico que involucra células vivas. Se discute el mecanismo redox de biofabricación de NPs, haciendo énfasis en aquellos puntos que requieren mayor dilucidación con el propósito de estandarizar los procesos para adaptarlos a un sistema industrial de producción. Se describe igualmente lo que se conoce acerca del destino de las NPs biofabricadas en células vivas, remarcando el proceso de movilización extra-e intracelular así como entre diferentes tejidos y órganos de la planta. Se discuten por último los factores que regulan la tasa de biofabricación de nanopartículas en las células y tejidos vivos, dirigiendo la atención hacia aquello que se necesita dominar para obtener biofábricas para la producción de NPs en donde la variabilidad de tamaño, forma y reactividad se ajusten a estándares industriales.Palabras clave: balance redox, bioproducción, bioreducción de metales, síntesis química verde. AbstractA review is presented on the biomanufacturing of nanoparticles (NPs) of metals using plant extracts, cell organ cultures or live plants. The two methods of manufacturing green nanoparticles are described: the biochemical process extracts and biological process involving living cells. The redox mechanism biomanufacturing of NPs is discussed, emphasizing those points that require further clarification in order to standardize processes to adapt to an industrial production system. It also describes what is known about the fate of NPs biomanufacturing in living cells, highlighting the process of extra-and intracellular as well as between different tissues and organs of the plant mobilization. Finally the factors discussed that regulate the rate of biomanufacturing of nanoparticles in living cells and tissues, directing attention to what you need to master to obtain bio-factories for the production of NPs where the variability in size, shape and reactivity fit to industry standards.

Trace element malnutrition causes the development of chronic degenerative diseases. The consumption of minerals and other compounds of biochemical origin through the intake of vegetables can attenuate these deficiencies to a great extent. Because the content in the plant depends on the conditions where it develops, there are still deficiencies that should be taken into consideration. For example, in Mexico, the intake of selenium does not cover the recommended daily requirement. The objective of this study was to use selenium nanoparticles (nSe) as a selenium (Se) source and to determine the effects on agronomic indices, antioxidant compounds, enzymatic activity, and accumulation of Se in fruits of a jalapeño pepper crop. Different concentrations of nSe (1, 15, 30, and 45 mg L−1) were supplied via drench to jalapeño pepper plants at 15, 30, 45, and 60 days after transplanting. The results indicate that applying nSe via drench with 45 mg L−1 increased crop yield and antioxidant compounds. Moreover, all doses evaluated modified the activity of the enzymes ascorbate peroxidase (APX), glutathione peroxidase (GSH-Px), and phenylalanine ammonium lyase (PAL), as well as improved the concentration of Se in fruits. The nSe incorporation via drench is an alternative to increase the content of Se and other nutraceutical compounds in jalapeño pepper fruits, possibly positively influencing human nutrition when consumed.

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The produced water is obtained during the extraction process of hydrocarbons, whose characteristics, composition and concentration depend on the reservoir that contains them. The waters produced contain hydrocarbons and heavy metals, and may contain essential elements for plant nutrition. Some studies indicate that for plants the most toxic components of the produced water are the hydrocarbons. This research aimed to evaluate the response in the pH and the electrical conductivity (EC) of irrigation leachate, morphological variables, mineral concentration and the generation of antioxidants in the tomato plants treated with diesel, gasoline and benzene in concentrations of 15 and 30 mg L-1, simulating the use of water produced for irrigation. An analysis of variance and tests of means of least significant difference was performed. The hydrocarbon treated plants reached the fifth cut of ripe fruits, except the treatment of diesel at 30 mg L-1, in which only 45% of the plants survived, and only the first harvest of ripe fruits was obtained. According to their type and concentration, the hydrocarbons produced both favourable and unfavourable changes in the pH, EC, stem diameter, plant height and dry fruit weight. Also, the hydrocarbons produced both beneficial and detrimental changes in the mineral concentration of the plants; however, the hydrocarbons inhibited the mineral concentration in the fruits. The level of ascorbate in the fruits was decreased, and the diesel treatments limited the accumulation of lycopene.