Funciones del óxido nítrico en la respuesta de la planta a la toxicidad por cadmio

Rodriguez-Gonzalez, A., Terron-Camero, L.C., Romero-Puertas, M.C. 2020. Nitric oxide functions in plant response to cadmium toxicity. Ecosistemas 29(2):1935. Doi.: 10.7818/ECOS.1935 Human activities have led to environmental pollution with heavy metals, including cadmium (Cd) which is one of the most toxic pollutants. Cd is released into the environment by mining and fertilizes application. Metal uptake by crop plants introduces Cd into the human food chain, posing to a human health concern. Although Cd is not an essential element, it can enter the roots and it is translocated throughout different tissues by a variety of unspecific transport systems, thereby competing with essential nutrients. Cadmium exposure affects numerous physiological and biochemical processes in plants and leads to limited growth and therefore yield chlorosis, and oxidative stress induced by the production of reactive oxygen species (ROS). Recently, the well-known signalling molecule, nitric oxide (NO), has been involved in plant response to Cd toxicity, although NO-dependent mechanisms are not fully characterized. In this review, the main sources for Cd contamination and the mechanisms involved in metal toxicity are discussed including the possible NO roles in plant response to this heavy metal. NO applied exogenously usually protects the plant mainly by induction of the antioxidant system. As an endogenous molecule, NO has been involved in the regulation of proteins related to oxidative metabolism, hormones, and transcription factors through posttranslational modifications