Mecanismos de respuesta frente a la deficiencia de nutrientes en el cultivo de Cacao en la costa ecuatoriana.

Cocoa is one of the most important crops not only for Ecuador, but also worldwide. Nutritional deficiencies in the crop, in general nutritional disorders, inhibit or decrease the growth and production of cocoa. When the plant fails to assimilate these chemical elements, it is forced to enter stress conditions. These conditions change depending on the plant species and its phenological age. However, the processes of photosynthesis and transpiration are seriously affected, but these actions can also produce response mechanisms that adjust their homeostasis through the expression of different biochemical processes, responsible for the transport and assimilation of nutrients. These substances produce the formation of elicitors that are still being studied, because their functions are not completely known. Under this context, the research work compiled information on the various plant mechanisms that plants use in response to nutrient deficiency. The results indicate that plants, as an alternative, use several chemical and physiological routes, to avoid energy waste. Among the main physiological responses, we have: the regulation of stomata, decrease in leaf area, increase in photon capture, lower respiration rates, lower amount of photoprotective pigments, photoinhibition, improved nutrient absorption in conjunction with symbionts. In relation to the chemical responses, we have epoxidation of xanthophylls, better carboxylation rates of ribulose, increase in the photochemical activity of PSII by cytochrome, increase in salicylate levels in the leaf and increase in the content of alkaloids/polyphenols. In this concept, the plant developed a unique capacity to cope, over time, with nutrient deficiency, avoiding energy consumption and loss in grain yield to a minimum.

Cocoa is one of the most important crops not only for Ecuador, but also worldwide. Nutritional deficiencies in the crop, in general nutritional disorders, inhibit or decrease the growth and production of cocoa. When the plant fails to assimilate these chemical elements, it is forced to enter stress conditions. These conditions change depending on the plant species and its phenological age. However, the processes of photosynthesis and transpiration are seriously affected, but these actions can also produce response mechanisms that adjust their homeostasis through the expression of different biochemical processes, responsible for the transport and assimilation of nutrients. These substances produce the formation of elicitors that are still being studied, because their functions are not completely known. Under this context, the research work compiled information on the various plant mechanisms that plants use in response to nutrient deficiency. The results indicate that plants, as an alternative, use several chemical and physiological routes, to avoid energy waste. Among the main physiological responses, we have: the regulation of stomata, decrease in leaf area, increase in photon capture, lower respiration rates, lower amount of photoprotective pigments, photoinhibition, improved nutrient absorption in conjunction with symbionts. In relation to the chemical responses, we have epoxidation of xanthophylls, better carboxylation rates of ribulose, increase in the photochemical activity of PSII by cytochrome, increase in salicylate levels in the leaf and increase in the content of alkaloids/polyphenols. In this concept, the plant developed a unique capacity to cope, over time, with nutrient deficiency, avoiding energy consumption and loss in grain yield to a minimum.

El cacao es uno de los cultivos de mayor importancia no solo para el Ecuador, sino también a nivel mundial. Las deficiencias nutricionales en el cultivo, en general los desórdenes nutricionales inhiben o disminuyen el crecimiento y la producción de cacao. Cuando la planta no logra asimilar estos elementos químicos la obligan a entrar en condiciones de estrés, estas condiciones son cambiantes dependiendo la especie vegetal y su edad fenológica. Sin embargo, los procesos de fotosíntesis y traspiración son seriamente afectados, pero estas acciones también puedo producir mecanismos de respuesta que ajustan su homeostasis mediante la expresión de diferentes procesos bioquímicos, responsables del trasporte y asimilación de nutrientes. Estas sustancias producen la formación elicitores que aún siguen en estudio, debido a que sus funciones no son conocidas completamente. Bajo este contexto el trabajo de investigación recopiló información sobre los diversos mecanismos vegetales, que las plantas utilizan como respuesta a la deficiencia de nutrientes. Los resultados indican que las plantas como alternativa utilizan varias rutas químicas y fisiológicas, esto con el fin de evitar desgaste energético. Entre las principales respuestas fisiológicas, tenemos: la regulación de estomas, disminución del área foliar, incrementando en la captura de fotones, menores tasas de respiración, menor cantidad de pigmentos fotoprotectores, fotoinhibición, mejora absorción de nutrientes en conjunto con simbiontes. Con relación a las respuestas químicas tenemos: epoxidación de las xantofilas, mejores tasas de carboxilación de la ribulosa, aumento de la actividad fotoquímica del PSII por citocromo, aumento de niveles de salicilato en hoja y aumento del contenido de alcaloides/polifenoles. En este concepto la planta desarrollo una capacidad única para sobrellevar, en el tiempo, la deficiencia de nutrientes, evitando en lo mínimo el consumo energético y perdida en el rendimiento de grano.