María de la Luz Guerrero-González

In recent years, phosphorus (P) nanoparticles have emerged as promising alternatives to conventional fertilizers. This study evaluated zeolite-fixed hydroxyapatite nanoparticles (nHAP) for greenhouse tomato cultivation, comparing their efficiency with phosphate rock (positive P input) and quartz sand (negative P Carrier). Material characterization by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and zeta potential analysis revealed that zeolite was identified predominantly as clinoptilolite, phosphate rock as phosphate-bearing aluminosilicates, and quartz sand as crystalline quartz; in all cases, the materials exhibited negatively charged surfaces. Hybrid fertilizers were formed through electrostatic interactions between zeolite and nHAP, confirming the successful development of a zeolite-based carrier for nanohydroxyapatite delivery. Application of 0.01 g·L⁻¹ nHAP increased the effective quantum yield of Photosystem II by 0.64 compared to the control at midday. Fruit firmness showed no significant differences among treatments. The highest sugar and soluble solids content was observed with 0.1 g·L⁻¹ nHAP (6.84 °Brix), whereas the 1 g·L⁻¹ treatment enhanced pigment concentrations, reaching 5.9 mg·g⁻¹/g chlorophyll a, 2.92 mg·g⁻¹ chlorophyll b, and 2.82 mg·g⁻¹ carotenoids. The 0.01 g·L⁻¹ dose of nHAP maintained quality characteristics and marginally increased yield; however, yield decreased at higher nHAP concentrations, opening new research opportunities to optimize this nanofertilizer.

Heavy metal contamination in soils is a growing concern due to anthropogenic activities, and Allium sativum (garlic) has shown tolerance to mercury pollution. We analyzed the physiological and molecular responses of garlic cloves exposed to HgCl₂ at 0, 5000, 23,000, and 46,000 mg/kg for 2, 3, and 4 h. The germination percentage was lower than 46,000 mg/kg Hg for 4 h. We also analyzed the expression levels of NAC transcription factors and found that AsNAC11 had higher expression at 46,000 mg/kg at 2 h; AsNAC17 was underexpressed and the maximum was at 2 h at 23,000 mg/kg. AsNAC20 had the highest expression (30 times more than the control) at 3 and 4 h with 23,000 mg/Kg. AsNAC27 showed the highest expression at 3 h with 23,000 mg/kg. The tissues exhibited a maximum Hg bioconcentration factor of 0.037 at 23,000 mg/kg, indicating moderate mercury absorption. However, at a concentration of 46,000 mg/kg, the BCF decreased to 0.023. Our in-silico analysis revealed that the analyzed AsNACs are associated with various abiotic stress responses. This study provides valuable insights into genes that could be utilized for genetic improvement to enhance crop resistance to mercury soil contamination.

El maíz nativo presenta una gran diversidad genética, dicha diversidad ha sido de suma importancia y base del mejoramiento genético para la resistencia a sequía, pero los estudios se han concentrado en la zona del sureste del país. El presente tuvo como objetivo evaluar las características morfológicas de 55 poblaciones de maíz nativo del estado de San Luis Potosí, evaluar la interacción genotipo x ambiente y la estabilidad en el rendimiento de grano bajo condiciones de temporal estricto. Se establecieron dos parcelas experimentales, la primera en Facultad de Agronomía y Veterinaria de la Universidad Autónoma de San Luis Potosí y la segunda en la localidad de Los Cerritos, municipio de Ahualulco, bajo un diseño de bloques al azar con dos repeticiones. En la localidad de Los Cerritos se tuvo una mejor expresión fenotípica por lo cual se utilizó para la caracterización morfológica, mientras que la variable rendimiento se analizó con un análisis de varianza combinado y posteriormente se aplicó el modelo de regresión en los sitios (SREG) para estudiar la interacción. La estabilidad fue modelada utilizando la gráfica GGE biplot. El análisis de varianza para la caracterización morfológica presentó diferencias altamente significativas para todas las variables. La evaluación de interacción genotipo x ambiente mostro que las poblaciones 5, 665 y 438 fueron las más estables y con el mayor rendimiento de grano.

Sedimentable solids generated in aquaponic systems are mainly composed of organic waste, presenting molecules such as phytate, which can be a potential source of inorganic nutrients through mineralization. This work aimed to isolate and identify phytase-producing bacteria and evaluate the inoculation effects of pure strains on mineralization and nutrient release from solid waste generated in aquaponic systems at different oxygen and temperature conditions. The bacteria were isolated from the settleable solids of a commercial aquaponic system and molecularly identified by amplifying the 16S rRNA gene. Subsequently, two tests were carried out: 1. Test for the biochemical identification of phytase-producing bacteria; 2. In vitro mineralization test, where the ability to mineralize phytate and release nutrients under different oxygen conditions [0 rpm (2.1 mg L⁻¹) and 200 rpm (7.8 mg L⁻¹)] and temperatures (24 and 37 °C) were evaluated. Our findings show that two pure strains of Lysinibacillus mangiferihumi can mineralize phytate under conditions of 200 rpm and 24 °C, mainly increasing the mineralization of PO4- and Ca, a property that has not yet been reported for this species. On the other hand, at 0 rpm and 24 °C, an increase in K was observed (control conditions), while the conditions of 200 rpm and 24 °C, regardless of bacterial inoculation, favored a rise in S, Mg, and Fe. The Lysinibacillus strains obtained in this investigation are of great importance due to their application in agriculture and the optimization of mineralization in aquaponic systems. A proper combination of oxygen and temperature will lead to a greater availability of nutrients for the growth and development of vegetables.

Opuntia megarrhiza is an endemic plant used in Mexican traditional medicine for the treatment of bones fractures in humans and domestic animals. One of the most used technique for the detection and characterization of the structure of phytochemical compounds is the Gas Chromatography Coupled to Mass Spectrometry. The goals of the present study were to identify and characterize the phytochemical compounds present in wild individuals of O. megarrhiza using this analysis. We used chloroform and methanol extracts from cladodes, and they were analyzed by gas chromatography-electron impact-mass spectrometry. We obtained 53 phytochemical compounds, 19 have been previously identified with some biological activity. Most of these compounds are alkanes, alkenes, aromatic hydrocarbons, fatty acids, and ketones. We detected some fragmentation patterns that are described for the first time for this species. The variety of metabolites presents in O. megarrhiza justifies the medicinal use of this plant in traditional medicine and highlight it as a source of phytochemical compounds with potential in medicine and biotechnology.

The establishment of plant–fungus mutualistic interaction requires bidirectional molecular crosstalk. Therefore, the analysis of the interacting organisms secretomes would help to understand how such relationships are established. Here, a gel-free shotgun proteomics approach was used to identify the secreted proteins of the plant Arabidopsis thaliana and the mutualistic fungus Trichoderma atroviride during their interaction. A total of 126 proteins of Arabidopsis and 1027 of T. atroviride were identified. Among them, 118 and 780 were differentially modulated, respectively. Bioinformatic analysis unveiled that both organisms’ secretomes were enriched with enzymes. In T. atroviride, glycosidases, aspartic endopeptidases, and dehydrogenases increased in response to Arabidopsis. Additionally, amidases, protein-serine/threonine kinases, and hydro-lyases showed decreased levels. Furthermore, peroxidases, cysteine endopeptidases, and enzymes related to the catabolism of secondary metabolites increased in the plant secretome. In contrast, pathogenesis-related proteins and protease inhibitors decreased in response to the fungus. Notably, the glutamate:glyoxylate aminotransferase GGAT1 was secreted by Arabidopsis during its interaction with T. atroviride. Our study showed that GGAT1 is partially required for plant growth stimulation and on the induction of the plant systemic resistance by T. atroviride. Additionally, GGAT1 seems to participate in the negative regulation of the plant systemic resistance against B. cinerea through a mechanism involving H₂O₂ production.

The objective of this experiment was to evaluate the effects of feeding different levels concentrations of dietary calcium propionate (CaPr) on lambs’ growth performance; ruminal fermentation parameters; glucose–insulin concentration; and hypothalamic mRNA expression for neuropeptide Y (NPY), agouti-related peptide (AgRP), and proopiomelanocortin (POMC). Thirty-two individually fed lambs were randomly assigned to four treatments: (1) control diet (0 g/kg of CaPr), (2) low CaPr, (30 g/kg dry matter (DM)), (3) medium CaPr, (35 g/kg DM), and (4) high CaPr (40 g/kg DM). After 42 days of feeding, lambs were slaughtered for collecting samples of the hypothalamus. Data were analyzed as a complete randomized design, and means were separated using linear and quadratic polynomial contrast. Growth performance was not affected (p ≥ 0.11) by dietary CaPr inclusion. The ruminal concentration of total volatile fatty acids (VFA) increased linearly (p = 0.04) as dietary CaPr increased. Likewise, a linear increase in plasma insulin concentration (p = 0.03) as dietary CaPr concentration increased. The relative mRNA expression of NPY exhibited a quadratic effect (p < 0.01), but there were significant differences in the mRNA expression of AgRP and POMC (p ≥ 0.10). Dietary calcium propionate did not improve lamb growth performance in lambs feed with only forage diets. Intake was not correlated with feed intake with mRNA expression of neuropeptides.

Herbal formulas during pregnancy have been used in developing countries. Despite that, the potential effects on the mother and offspring and whether those supplements elicit epigenetic modifications is still unknown. Therefore, our objectives were to determine the effects of supplemental herbal choline source (BCho) on the percentage of 5-hmC in whole blood from gestating ewes and their offspring, as well as determining the milk quality and growth of the offspring. Thirty-five gestating Rambouillet ewes were randomly assigned to five treatments: T1, supplementation of 4 g per day (gd⁻¹) of BCho during the first third of gestation; T2, supplementation of 4 gd⁻¹ of BCho during the second third of gestation; T3, supplementation of 4 gd⁻¹ of BCho during the last third of gestation; T4, supplementation of 4 gd⁻¹ of BCho throughout gestation; and T5, no BCho supplementation (control). For the 5-hmC DNA analysis, whole blood from ewes was sampled before pregnancy and at each third of gestation (50 days). Whole blood from lambs was sampled five weeks after birth. The evaluation of the nutritional programming effects was conducted through the percentages of 5-hmC in the lambs. Compared with other treatments, the whole blood from ewes supplemented during T1 and T4 had the greatest 5-hmC percentages (p < 0.05). However, only ewes fed BCho throughout gestation (T4) maintained the greatest percentages of 5-hmC (p < 0.05). The lamb growth performance indicated that the BCho maternal supplementation did not affect the nutritional programming. However, the lambs born from ewes supplemented during T2 had the greatest 5-hmC percentages (p < 0.05). Our data suggest that ewes supplemented during T4 with BCho increase and maintain the percentages of 5-hmC in whole blood, and the offspring born from ewes supplemented with BCho during T2 maintained the greatest percentages of 5-hmC 35 d after they were born.

Dehydrins (DHNs) are intrinsically disordered proteins expressed under cellular dehydration-related stresses. In this study, we identified potential proteolytic PEST sequences located at the central and C-terminal regions from the Opuntia streptacantha OpsDHN1 protein. In order to evaluate these PEST sequences as proteolytic tags, we generated a translational fusion with the GUS reporter protein and OpsDHN1 coding sequence. We found a GUS degradation effect in tobacco agro-infiltrated leaves and Arabidopsis transgenic lines that expressed the fusion GUS::OpsDHN1 full-length. Also, two additional translational fusions between OpsDHN1 protein fragments that include the central (GUS::PEST-1) or the C-terminal (GUS::PEST-2) PEST sequences were able to decrease the GUS activity, with PEST-2 showing the greatest reduction in GUS activity. GUS signal was abated when the OpsDHN1 fragment that includes both PEST sequences (GUS::PEST-1-2) were fused to GUS. Treatment with the MG132 proteasome inhibitor attenuated the PEST-mediated GUS degradation. Point mutations of phosphorylatable residues in PEST sequences reestablished GUS signal, hence these sequences are important during protein degradation. Finally, in silico analysis identified potential PEST sequences in other plant DHNs. This is the first study reporting presence of PEST motifs in dehydrins.