Miriam Irene Jiménez-Pérez

The agave wilt associated with Fusarium oxysporum (Fox) is a major disease of blue agave (Agave tequilana Weber var. azul), used to produce “Tequila” in Mexico. Little is known about the A. tequilana-F. oxysporum interaction yet understanding defense mechanisms against the pathogen is necessary for control strategies. During early Fox infection, plants trigger defense mechanisms to interrupt the compatible interaction, while Fox’s pathogenesis mechanism interacts with plant response. This study evaluated plant defense mechanisms induced by Fox in A. tequilana and their interaction with fungal pathogenesis. For this, an A. tequilana pathogenic strain (FPA), and the non-A. tequilana pathogenic strains FNPA and FOL were utilized. Early defense mechanisms evaluated were hypersensitive response (HR) and cell wall strengthening in agave roots. Resistance mechanisms evaluated included pathogenesis-related proteins (PR proteins), phytoanticipins and phytoalexins. For early defense, induced HR was greater with FPA than other strains. Cell wall strengthening was found in agave roots, plants responded differentially to different strains. Initial response to FPA and FOL was similar in PR proteins, phytoalexins and phytoanticipins production. However, the response differentiated with FOL over time, indicating an incompatible interaction. The study identified effective and ineffective defense responses of A. tequilana to Fox infection, where FPA exhibited compatibility and caused unregulated ROS and PCD, early inhibition of PR activity, extensive lignification, and saponin detoxification. In contrast, this study unveiled incompatible interactions (FNPA and FOL) because of limited colonization, localized HR with suppressed ROS, early and sustained POX activation, significant callose accumulation, moderate lignification, and phenol–saponin dynamics that help in tissue containment and recovery.

In this work, extracts from the pulp, peel, and seed of Manilkara zapota were obtained via lyophilization and oven drying. Bromatological analyses were performed to investigate variabilities in the nutritional content of fruits after nine post-harvest days. The phytochemical content of fruits was assessed by gas chromatography flame ionization detector (GC-FID), and their biological performance was studied using in vitro antibacterial and antioxidant assays (DPPH and ABTS) and in vivo toxicity models. Molecular docking was implemented to evaluate the interaction between polar compounds from chicozapote fruits with receptors involved in the pathogenesis of bacterial strains. Results revealed that water or soluble solids content did not vary after post-harvest. It was demonstrated that lyophilization or oven-drying approaches influenced the insoluble, total dietary fiber and digestible carbohydrates among samples. According to GC-FID analysis, it was observed that lyophilization and oven-drying methods also altered the content of myristic and pentadecanoic acids among the obtained extracts. It was noted that the antibacterial and antioxidant activities of extracts were weak due to their MIC (>1000 μg/mL) and IC₅₀ (>2000 μg/mL) values. Still, the toxicity of extracts was poor against Artemia salina nauplii. In silico evaluation unveiled that polar compounds in M. zapota fruits possess a high binding affinity towards the DNA gyrase B of the cultured strains. This study expands the scientific evidence regarding the influence of distinct extraction methods on the nutritional and nutraceutical content of native fruits and the importance of considering additional approaches to enhance their bioactivities.

This paper explores the introduction of problem-based learning (PBL) in Biomedical Engineering at Tecnologico de Monterrey, comparing experiences from 2014 to 2019 between medical and biomedical engineering students. Medical students consistently outperform biomedical engineering counterparts, attributed to higher admission standards. Despite minor improvements in biomedical engineering grades, the differences remain statistically insignificant. Initial challenges for students involve adapting to a self-directed learning model. Biomedical engineers excel in cell biology compared to biochemistry courses. Students recognize PBL's benefits in acquiring theoretical knowledge and facing intellectual challenges, emphasizing its value in biomedical engineering education. We conclude that PBL implementation should be considered in other engineering courses.