Effect of titanium foliar applications on tomato fruits from plants grown under salt stress conditions

Salt stress affects plant metabolism, while beneficial elements such as titanium (Ti) may stimulate adaptive responses to mitigate salt stress. Here we evaluated the main effects of sodium chloride (NaCl 0, 50 and 100 mM) in the nutrient solution, and of titanium foliar spray (Ti 0.75 and 150 mg L-1), as well as the interaction of these study factors, on tomato cv. ‘Rio Supremo’ performance in greenhouse. Plants were treated with NaCl during 80 d through automated drip irrigation; while eight Ti foliar sprayings were applied with a manual sprayer, at intervals of 10 d each. Yield and quality parameters of fruits were evaluated in the second cluster. NaCl reduced yield parameters, pH value and increased the titratable acidity (TA), electrical conductivity (EC), and total soluble solids (TSS), as well as the TSS/TA ration in the fruits. Ti did not affect yield parameters, though it reduced the pH and increased the TSS/TA ratio of fruits. NaCl and Ti have differential effects on fruit quality as separate factors, while the interaction of both factors revealed that Ti effects dependent on the presence of NaCl and its level in the nutrient solution. In conclusion, Ti did not mitigate the negative effects of saline stress on the evaluated yield parameters, but importantly, with moderate levels of NaCl in the nutrient solution (50 mM), Ti increased EC, TA and TSS of fruits

Biostimulant effects of lanthanum (La) on crop growth, yield, and quality

Objective: To analyze the various effects that the use of La as an inorganic biostimulant has on growth, yield and quality of different crop plants. Design/methodology/approach: A search in recent literature related to the effects of lanthanum on various economically important crops was conducted. Subsequently, the most relevant information was selected, analyzed and grouped by type of effect. Results: The addition of lanthanum at low doses has been tested in different crop plants. It has been proven that La increases growth, development and quality in various species. Likewise, positive effects have been reported in germination, in the absorption of nutrients, in mitigating the deficiencies of some essential elements, as well as in the promotion of physiological and biochemical responses. Limitations/implications of the study: The analyzed results have been generated in a great diversity of plant species, under different production systems, with dissimilar doses, as well as with different sources and application methods. This situation represents a challenge, since it hinders the possibility to issue general recommendations. Findings/conclusions: Lanthanum improves yield and quality, as well as some physiological, biochemical and nutritional responses in different crops of economic importance

La exposición de plantas de arroz (Oryza sativa L.) a nanopartículas de plata afecta la expresión de genes multifuncionales NAC

Objective: We aimed to evaluate the effect of silver nanoparticles (AgNPs) on the expression of 17 NAC genes in rice plants (Oryza sativa L.) under greenhouse conditions. Methodology: Twelve-d-old rice seedlings were transferred to a hydroponic system. Fourteen days after the transplant, the following treatments were applied through the nutrient solution: 0, 20, 40 and 80 mg L-1 AgNPs. Each solution had six repetitions which were distributed in a completely randomized experimental design. From the treated and control plants, total RNA was extracted from stems, from which cDNA was synthesized and a measurement of gene expression was performed by the qRT-PCR technique. The elongation factor 1?, which showed greater stability, was taken as the reference gene. The relative expression of the genes was determined using the 2-??Ct method, with a differential expression value of 2. Results: It was found that the AgNPs induced the expression of four NAC genes (Os02g56600, Os07g04560, Os12g43530 and Os06g5107) by at least one dose of AgNPs tested, and one gene (0s08g10080) showed repression of expression by the presence of these nanoparticles in the nutrient solution. In the Os07g04560 gene, the expression was dependent on the concentration of AgNPs, that is, the higher the concentration of AgNPs in the medium, the greater the expression of the gene. Limitations: In further studies, it would be necessary to explore the expression of more NAC genes in different tissues and phenological stages of the plant. Conclusions: It is concluded that silver nanoparticles differentially affect the expression of NAC genes in rice, which confirms the multifunctionality of these genes in plants.Objetivo: El objetivo de este estudio fue evaluar el efecto de las nanopartículas de plata (AgNPs) en la expresión de 17 genes NAC en plantas de arroz (Oryza sativa L.) en invernadero. Plántulas de arroz de 12 d de edad se trasfirieron a un sistema hidropónico. Catorce días después del trasplante se aplicaron los siguientes tratamientos a través de la solución nutritiva: 0, 20, 40 y 80 mg L-1 AgNPs. Cada tratamiento tuvo seis repeticiones en un diseño experimental completamente al azar. De las plantas tratadas y del testigo se extrajo RNA total de vástago, a partir del cual se sintetizó cDNA y se realizó una medición de la expresión génica por la técnica de qRT-PCR. Como gen de referencia se tomó el Factor de elongación 1?, que mostró mayor estabilidad. La expresión relativa de los genes se determinó utilizando el método 2-??Ct, con un valor de expresión diferencial de 2. Resultados: Se encontró que las AgNPs indujeron la expresión de cuatro genes NAC (Os02g56600, Os07g04560, Os12g43530 y Os06g5107) por al menos una dosis de AgNPs probada, y un gen (0s08g10080) mostró represión de la expresión por la presencia de estas nanopartículas en la solución nutritiva. En el gen Os07g04560, la expresión fue dependiente de la concentración de AgNPs, esto es, a mayor concentración de AgNPs en el medio, mayor expresión del gen. Limitaciones: En este estudio no fue posible analizar la expresión de genes NAC en respuesta a AgNPs en otros tejidos y en otras etapas fenológica. Conslusiones: Las nanopartículas de plata afectan diferencialmente la expresión de genes NAC en arroz, lo que corrobora la multifuncionalidad de estos genes en plantas

Silicon and titanium affect the percentage of juice and color attributes in tomato fruits of plants exposed to salt stress

Objective: To evaluate the leaf application of silicon (Si) and titanium (Ti) in three doses (0, 75, and 150 mg L-1), independently, on tomato plants cv. Río Supremo, subjected to saline stress (0, 50, and 100 mM NaCl), on the percentage of juice and color attributes of the fruit. Design/methodology/approach: Two independent essays were carried out under a completely randomized experimental design in a 32 factorial arrangement, where the first study factor was the NaCl concentration in the nutrient solution and the second factor was the leaf application of Si or Ti. The percentage of juice and color attributes in fruits were determined. An analysis of variance and the comparison of means by Tukey (p ≤ 0.05) with the SAS software were performed. Results: Salinity was found to reduce the percentage of juice, the color index, and the ratio of “a/b” indexes. Regarding the interactive effects, NaCl with both Ti and Si increases the “b” index. Leaf applications of Si increased the “b” index and reduced the percentage of juice, the color index, and the ratio of “a/b” indexes. Also, Ti improved the color index and the “b” index. Limitations of the study/implications: The results were obtained in the Río Supremo tomato variety under greenhouse conditions. Other varieties should be tested too. Findings/conclusions: Si and Ti applied to the leaves have positive effects on the color of the fruits of tomato plants under saline stress

Glucosinolates: Structure, classification, biosynthesis and functions in higher plants

ABSTRACT Objective: To analyze concepts, structure, classification, biosynthesis and functions of glucosinolates (GSLs) in higher plants. Design/methodology/approach: A search was performed into recent high-impact literature related to glucosinolates (GSLs). Results: GSLs are secondary metabolites rich in N and S. They are divided into aliphatic, aromatic, and indole GSLs depending on the amino acid from which they arise. The products of their hydrolysis, mediated by thioglucoside glucohydrolase, thioglucosidase or myrosinase enzymes (EC 3.2.1.147), play a role in increasing tolerance to biotic and abiotic stress factors. Furthermore, given their composition, they can serve as a nutrient reservoir under nutrient deficiency conditions. Limitations on study/implications: GSLs are synthesized only in species of the Capparidaceae, Brassicaceae, Resedaceae, and Moringaceae families. Findings/conclusions: GSLs are sulfur compounds that can serve as defense mechanisms against biotic and abiotic stress factors and as sources of nutrients in plants, and molecules with important nutraceutical properties in food and human health.Objective: To analyze concepts, structure, classification, biosynthesis and functions of glucosinolates (GSLs)in higher plants.Design/methodology/approach: A search was performed into recent high-impact literature related toglucosinolates (GSLs).Results: GSLs are secondary metabolites rich in N and S. They are divided into aliphatic, aromatic, andindole GSLs depending on the amino acid from which they arise. The products of their hydrolysis, mediated bythioglucoside glucohydrolase, thioglucosidase or myrosinase enzymes (EC 3.2.1.147), play a role in increasingtolerance to biotic and abiotic stress factors. Furthermore, given their composition, they can serve as a nutrientreservoir under nutrient deficiency conditions.Limitations on study/implications: GSLs are synthesized only in species of the Capparidaceae, Brassicaceae,Resedaceae, and Moringaceae families.Findings/conclusions: GSLs are sulfur compounds that can serve as defense mechanisms against bioticand abiotic stress factors and as sources of nutrients in plants, and molecules with important nutraceuticalproperties in food and human health

Silicon increases seed weight and initial seedling growth of maize under non-stress conditions, and improves the index of velocity of germination under salt stress conditions

Salinity is one of the most critical factors affecting agriculture worldwide. The application of beneficial elements like silicon (Si) is one of the alternatives to mitigate its effects. In this research, we evaluated the effect of Si applied during seed imbibition on mitigating the negative effects caused by salinity during the germination and initial growth phases of maize (Zea mays L.) SB-308 seedlings. Seed pre-treatment during the imbibition was made with 0.0-, 1.5- and 3.0-mM Si. Afterwards, seeds that were imbibed were placed in plastic containers and treated with 0, 80, 160, and 240 mM NaCl. The evaluated concentrations of Si and NaCl gave rise to 12 treatments. Pre-treated seeds with 3 mM Si had an increase of weight after imbibition, 5.1% higher than the control. The treatments obtained from combining NaCl and Si levels did not affect the total and relative germination. The radicle length increased by 13.6% with 3 mM Si compared to the control. Conversely, it was lower with increasing salinity. These trends were observed in plant height. The interaction of the study factors produced an increase in the radicle length in the interval from 0 to 160 mM NaCl, when the Si dose was increased. However, there were no significant differences among equal levels of salinity without Si. It is concluded that Si increased the absorption of water during the imbibition and raised the index of velocity of germination under salinity, except in the dose 240 mM NaCl. Likewise, the pre-treatment of seeds with Si tends to increase radicle length under saline conditions

EFECTO DEL ÁCIDO SALICÍLICO EN EL CRECIMIENTO DE LA RAÍZ Y BIOMASA TOTAL DE PLÁNTULAS DE TRIGO

Se reportan los resultados de dos experimentos independientes para evaluar el efecto del ácido salicílico (AS) en plántulas de trigo (Triticum aestivum L.). Las plántulas de ambos experimentos se germinaron y crecieron en agrolita contenida en tubos de PVC y en condiciones de cielo abierto bajo un diseño experimental completamente al azar con 8 repeticiones por tratamiento, las plántulas se asperjaron durante 5 días con 1 y 0.1 µM de AS o agua como control. Diez días después fueron cosechadas y realizadas las mediciones. Los resultados señalan que el AS favoreció significativamente el peso fresco de la raíz, así como la altura y el peso fresco de la biomasa total, en comparación con el control. El mejor tratamiento para estimular el crecimiento de plántulas de trigo fue el de 1µM de AS

Efecto del diámetro de partícula de tezontle en tomate (Solanum lycopersicum L.), pepino (Cucumis sativus L.) y lechuga (Lactuca sativa L.) en acuaponía

En la acuaponía el uso de sustrato permite la colonización de bacterias nitrificantes y actúa como biofiltro. El diámetro de partículas del sustrato puede ser determinante en la colonización del sustrato por las bacterias y puede afectar el desarrollo y rendimiento de las plantas; razón por la que en esta investigación se planteó la hipótesis de que tamaño de partícula del tezontle afecta la colonización de bacterias y el desarrollo y crecimiento de las plantas. El experimento consistió de recipientes de 120 L como estanques para los peces, y de 12 tinas de 240 L para el sustrato y una bomba para oxigenación auxiliar a los estanques de los peces. Se establecieron 3 cultivos en cada tina: tomate, pepino y lechuga. Estos cultivos fueron trasplantados en 3 granulometrías de tezontle: diámetro menor a 1 cm, mayor a 5 cm y mezcla 50:50% de ambos tamaños con tres repeticiones por tratamiento. Se realizó un análisis de la varianza y prueba de Tukey. No hubo efecto del diámetro de partícula del sustrato en la altura, diámetro de tallo y lecturas SPAD en las plantas de tomate, pepino y lechuga. El diámetro de partícula del sustrato no afectó el rendimiento ni firmeza, acidez titulable y grados Brix en los frutos de tomate. Tampoco hubo efecto sobre rendimiento y de calidad de frutos de pepino. En lechuga el peso fresco correspondiente al sustrato con partículas menores a 1 cm fue 55% mayor al de partículas mayores a 5 cm: 89.87 y 50.12 g por planta, respectivamente. El diámetro de partícula no afecta el rendimiento ni la calidad de los cultivos establecidos, sin embargo, en términos prácticos el tezontle fino menor a un cm es recomendable porque tiene mayor capacidad retención de humedad y mayor superficie para que las bacterias colonicen el medio

Efecto de la Relación Nitrato: Amonio en Solanum nigrescens Mart. & Gal.

La presente investigación se realizó en un invernadero del Colegio de Posgraduados (CP), Campus Montecillo, ubicado en el municipio de Texcoco, Estado de México, de enero a diciembre de 2022, con el objetivo de investigar la respuesta de la hierbamora (Solanum nigrescens Mart. & Gal.) a cuatro niveles de la relación nitrato:amonio (100:0, 75:25, 50:50 y 25:75) respecto a rendimiento de fruto y en variables agronómicas y fisiológicas. El diseño experimental fue completamente al azar, con cuatro tratamientos y nueve repeticiones. Cada unidad experimental consistió de una planta en una maceta de 40 × 40 cm, con 13 L de tezontle como sustrato. La toma de datos de variables morfológicas y fisiológicas se llevó a cabo desde la germinación hasta cosecha. Se realizó una poda de formación a los 50 días después del trasplante. Se analizaron los datos en términos agronómicos, nutricionales y de calidad de frutos. Se evaluó altura, rendimiento, peso fresco y seco de biomasa, sólidos solubles totales, análisis químico de tejido foliar, análisis de iones específicos en extracto celular de hoja y jugo de frutos de hierbamora y concentración de azúcares totales en frutos maduros. Con la relación 75:25 se obtuvieron los mayores valores en biomasa, rendimiento y resultados significativos en la concentración de macronutrientes y micronutrientes en hoja. En azúcares totales en fruto la relación 50:50 obtuvo las mayores concentraciones

Biostimulant Effects of Cerium on Seed Germination and Initial Growth of Tomato Seedlings

The rare earth element (REE) cerium (Ce) can act as a biostimulant in diverse crop plants. The effects of 0, 5, 10, and 15 µM Ce (supplied as CeCl3 7H2O) on seed germination and the initial growth of tomato (Solanum lycopersicum L.) cv. Vengador were evaluated. After a 12 h imbibition, the weight of the seeds treated with 15 µM Ce was 37.5% greater than that observed in the control. The germination index of the seeds treated with 5 µM Ce was greater than 100% (101.93%), though when applying 10 µM Ce this index was 17.53% lower than the control seeds. Nevertheless, Ce treatments did not significantly affect the coefficient of velocity of germination, relative seed germination, germination index, radicle length, dry biomass, or relative growth. Interestingly, shoot length increased significantly in the treatments with 5, 10, and 15 µM Ce. This tendency was also observed in the dry biomass weight and relative growth of the shoots. Hence, Ce has a stimulating effect on germination and initial growth in tomato cv. Vengador shoots. In particular, there was a priming effect of Ce on seeds, reflected in a higher weight gain in Ce-treated seeds, which indicated greater water absorption. Therefore, Ce can be an alternative to accelerate the production time of tomato seedlings in seedbeds