Estudio del efecto de la sequía inducida por polietilenglicol en Capsicum frutescens en un sistema hidropónico

La sequía es el factor más común que limita el desarrollo y productividad de los cultivos, afectando severamente a la agricultura. En México, uno de los cultivos de importancia económica y gastronómica sensible al estrés hídrico es el género Capsicum. En el presente estudio se evaluó la aplicación de prolina en plantas de Capsicum frutescens expuestas a sequía inducida por polietilenglicol (PEG) en un sistema hidropónico. Empleando un diseño factorial 22, se evaluaron un total de 60 plántulas durante 120 h dividas en cuatro tratamientos: PEG (0 y 10 %) y Pro (0 y 10 mM) como variables de estudio. Los resultados demostraron que la exposición a 10 mM de Pro indujo un aumento significativo en la concentración de clorofila y de prolina endógena (hoja y raíz) en las plántulas en ausencia de estrés. Además, se observó un 80 % de supervivencia de las plántulas y un aumento en el contenido de prolina en aquellas que estuvieron expuestas a 10 mM Pro + 10 % PEG. De igual manera, se presentó un aumento en el contenido de clorofila (13 µg • mL-1), contenido relativo de agua (CRA) en raíz (77.6 %), porcentaje de electrolitos en hoja y raíz (~44 y ~52 % respectivamente), en comparación con el tratamiento de 0 mM Pro + 10 % PEG. Los resultados sugieren que la aplicación previa de prolina tiene un efecto positivo en la supervivencia de las plántulas bajo condiciones de sequía inducida por PEG

Physiological, Biochemical, and Molecular Response in Siete Caldos Chili Pepper Plants (<i>Capsicum frutescens</i>) Exposed to Water Deficit

Drought, exacerbated by climate change, represents a growing challenge for agriculture, significantly impacting on crops such as chili peppers (Capsicum), essential in the global diet. This work evaluated the response to water stress by suspending irrigation in Siete Caldos chili pepper plants (Capsicum frutescens). Control plants were watered every 48 h, while stress was induced in the test plants by withholding irrigation for 14 days, followed by an evaluation of recovery through rehydration on day 15. Growth parameters such as the fresh weight of the aerial part, root length, and number of flower buds showed significant differences between the two groups from the eighth day onwards. However, physiologically and biochemically stress-induced decreased relative water content, membrane stability, and chlorophyll content, coupled with increased electrolyte leakage, proline content, and antioxidant activity (catalases and peroxidases), were observed starting on the third day. These effects were more severe on day 14. At the molecular level, the expression of stress response genes (AP2, LOX2, CAT, CuSOD, MnSOD, and P5CS) was quantified at days 3, 14, and 15, revealing differences in transcript levels between the treatments. Finally, rehydration in the stressed plants resulted in the recovery of the evaluated parameters and a survival rate of 100%. Therefore, chili pepper has tolerance mechanisms that allow it to withstand a period of 14 days without irrigation, without reaching its permanent wilting point, and it can recover if conditions improve. This study underscores the complexity of plant responses and tolerance mechanisms to drought, providing insights into the behavior of semi-domesticated species

Chemical composition and antifungal activity of essential oils extracted from Pimenta dioica and Piper auritum leaves grown in Mexico

AbstractDiseases caused by mycotoxin-producing fungi, especially Aspergillus ochraceus and Fusarium moniliforme, are on the rise, leading to contamination of agricultural products and seeds during processing and storage, resulting in significant economic losses and posing serious health risks to humans and animals. Controlling these diseases primarily relies on synthetic fungicides, which can leave behind toxic residues harmful to human and animal health, as well as the environment. Various strategies have been proposed for controlling these fungal diseases, including biological control using essential oils (EOs) derived from plants. EOs extracted from plants of the Piper and Pimenta genera contain secondary metabolites with antimicrobial properties. This study aims to analyze the effect of EOs from Piper auritum and Pimenta dioica on the fungi A. ochraceus and F. moniliforme. The EOs were obtained through steam distillation, and their antifungal activity was assessed using minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and % sporulation. The phytochemical composition of the EOs was determined by GC-MS. The fungal species exhibited susceptibility to the EOs, with MIC and MFC values of 0.16 and 1.21 mg/mL, respectively, for P. dioica against A. ochraceus, and 0.43 mg/mL against F. moniliforme. Meanwhile, the MIC and MFC values for P. auritum were 0.16 and 15 mg/mL, respectively, against A. ochraceus. The EOs demonstrated effective antifungal activity, likely attributed to the presence of bioactive compounds