Four compounds, the flavone linarin (1), the triterpene lupenone (2), the tocopherol (vitamin E, 3), and the new natural alkaloid 1,2,3,4-tetrahydro-1,1-dimethyl-6,7-isoquinolindiol (affineine, 4), were the major natural products isolated from Zanthoxylum affine (syn. Zanthoxylum fagara, Rutaceae). Compound 1 is highly abundant in this plant and was isolated as a white precipitate obtained from the acetone and methanol extracts. The structure of these four compounds was established by 1D and 2D NMR spectroscopy including 1H, 13C, DEPT, COSY, HSQC, and HMBC experiments. The hexane, acetone, and methanol extracts, as well as 1, were evaluated for their potential phytotoxic effects in pre- and post-emergent assays, as well as to identify their mechanisms of action. As pre-emergent phytotoxic agents, the hexane, acetone, and methanol extracts inhibited germination and residual growth (root and stem elongation) of Lactuca sativa (lettuce) and Lolium perenne (perennial ryegrass). As post-emergent agents, they inhibited dry biomass. Compound 1 acts as a pre-emergent herbicide, by inhibiting germination, seed respiration, residual seedling growth and, notably, root hair development. Furthermore, 1 inhibited the synthesis of ATP and the electron transport chain of isolated spinach chloroplasts; in this way, it behaves as a Hill reaction inhibitor. The site of inhibition was located at the donor site of PSII from the oxygen evolving complex to QA, thus acting as a multisite compound. These results suggest that compound 1 can be used as a lead for a potential green herbicide with different targets.

<p>COVID-19 has had an impact on the regional and worldwide agricultural value chain, jeopardizing food security. It is time to reassess the approach of the agri-food sector and to consider that the food supply and plant health, as agrosystemic services, must depend on strategies with a low impact on productive and environmental assets. One strategy is the use and optimization of microbial genetic resources (MGR) related to agroecosystems as a source of balance, functionality, productivity, inhibition of the impact of pests and pathogens, and contribution to the profitability of agri-food activity. It is necessary to strengthen and develop regional agricultural systems that are dynamic, that mitigate damages to the environment and produce nutritional and nutraceutical foods that ensure human health. Agricultural sciences are undergoing changes in scientific paradigms that will benefit the agri-food sector if we are able to learn from the impacts of an extensive technological agriculture. Approaching agriculture from an agro-systemic point of view in which the crop-community is the functional biological unit of study and to preserve the MGR diversity are the greatest challenges to create sustainable and resilient strategies and technologies that contribute towards human health and help prevent risks during health crises such as the ongoing COVID-19 pandemic.</p>

<p>Actualmente, los estudios sobre agentes de control biológico de origen microbiano (ACB-M) generalmente están enfocados en la caracterización taxonómica mediante el uso de marcadores moleculares convencionales y en evaluar la capacidad antagónica/mecanismos de acción <em>in vitro</em>, en invernadero y eventualmente bajo condiciones de campo. Los ACB-M se centran principalmente en cepas de <em>Trichoderma</em>, <em>Paecilomyces, Beauveria</em>, <em>Pseudomonas</em> y <em>Bacillus</em>. Aunque la investigación en México en este campo ha sido muy activa en los últimos años, el desarrollo e innovación de una mayor diversidad de bioplaguicidas registrados y comercializados puede ser potenciada. En este contexto, el uso de técnicas vanguardistas en la era de las ciencias ómicas (genómica, transcriptómica, y metabolómica) enfocadas a la correcta afiliación taxonómica de los ACB-M y en el estudio de mecanismos de acción y comportamiento agroecológico es determinante para la bioprospección y uso extensivo de estos ACB-M de manera eficaz, biosegura y costo-efectiva. En el marco de la celebración internacional de la sanidad vegetal, la presente revisión analiza críticamente el estado del conocimiento y de aquellos aspectos que limitan la bioprospección y el uso extensivo de ACB-M con énfasis en México, desde la aplicación de las ciencias ómicas para la identificación, selección y estudio de los mecanismos de acción de dichos agentes hasta la difusión y socialización del conocimiento científico generado. Se pretende promover la reflexión sobre este campo del conocimiento e incentivar la nueva generación ACB-M con una visión holística y sistémica en beneficio de una agricultura sustentable y resiliente.</p>

The fungus Fusarium oxysporum f. sp. gladioli is one of the main pathogenic microorganisms of the ornamental genus Gladiolus. The attack of this microorganism includes corms and different plant phenological stages. In this study, different microscopic techniques and fluorochromes were used to evaluate the effect of J. curcas oil and acylglycerides, namely trilinolein, triolein, monomyristin and dimyristin, on the morphology, membrane integrity (%), viability (%) and germination (%) of F. oxsporum f sp. gladioli. Phase-contrast optical photomicrographs and scanning microscopy showed that J. curcas oil and the triglycerides triolein and trilinolein caused the formation of numerous vacuoles, alterations in the morphology of the outer covering of the mycelium and conidia, and inhibition of membrane activity in the fungus during 24 h of incubation. The fluorochromes used detected no permanent damage to the viability of the conidia. The high germination percentage of the conidia of Fusarium oxysporum f. sp. gladioli indicates that the damage caused by the application of the treatments was fungistatic rather than fungicidal and did not cause cell death.

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