Nitric oxide (NO) is a free radical involved in plant development and in response to stress conditions. Peroxisomes are organelles which are known to be a NO source [1]. Cadmium (Cd) pollution is a factor limiting the growth and productivity of important crops and is also a risk for human health throughout the food chain. It is known that, for a proper plant root development, both under physiological and stress conditions, a cross-talk between hormones and specific contents of ROS and NO is needed [1]. Catalase (CAT) is an antioxidant enzyme found in peroxisomes which, by catalyzing the H2O2 into water and oxygen, contributes to regulate ROS content in plant cells. The goal of the study was to highlight how Cd affects NO cellular content, CAT activity, peroxisomes distribution and root development in Arabidopsis thaliana. To this, 14-day-old transgenic plants expressing cyan fluorescent protein (35S:CFP) through the addition of the peroxisomal targeting signal 1 (PTS1), which enables peroxisomes to be visualized in vivo, were grown in the presence of 60 μM CdCl2. Moreover, using a cell-permeable NO specific fluorescent probe by confocal laser scanning microscopy (CLSM), we studied how Cd affects NO root content. Data indicate that Cd altered both Arabidopsis root morphology and NO distribution. The pollutant increased the length and density of lateral roots (LRs), whereas reduced the primary root (PR) length. In addition, Cd increased NO levels in the LRs and decreased it in the PR. PTS1 signal was changed by Cd only in the PR, showing a decrease of peroxisomes distribution and intensity. Furthermore, biochemical assays indicated that Cd negatively affects CAT activity. Our findings suggest that Cd affects H2O2 metabolism and NO content by acting on peroxisomes activity, leading to root architecture alteration and confirming the role of these organelles in the mechanisms of response against this pollutant.
Analysis of the peroxisomal nitric oxide content and root architecture in Arabidopsis seedlings grown under cadmium-induced stress / Piacentini, Diego; Falasca, G.; Altamura, M. M.; Corpas, F. J.. - (2019), pp. 62-62. (Intervento presentato al convegno XII GEIRLI Meeting: New trends in redox biology: a multidisciplinary approach tenutosi a Barcellona).
Analysis of the peroxisomal nitric oxide content and root architecture in Arabidopsis seedlings grown under cadmium-induced stress
Diego Piacentini;Falasca G.;Altamura M. M.;
2019
Abstract
Nitric oxide (NO) is a free radical involved in plant development and in response to stress conditions. Peroxisomes are organelles which are known to be a NO source [1]. Cadmium (Cd) pollution is a factor limiting the growth and productivity of important crops and is also a risk for human health throughout the food chain. It is known that, for a proper plant root development, both under physiological and stress conditions, a cross-talk between hormones and specific contents of ROS and NO is needed [1]. Catalase (CAT) is an antioxidant enzyme found in peroxisomes which, by catalyzing the H2O2 into water and oxygen, contributes to regulate ROS content in plant cells. The goal of the study was to highlight how Cd affects NO cellular content, CAT activity, peroxisomes distribution and root development in Arabidopsis thaliana. To this, 14-day-old transgenic plants expressing cyan fluorescent protein (35S:CFP) through the addition of the peroxisomal targeting signal 1 (PTS1), which enables peroxisomes to be visualized in vivo, were grown in the presence of 60 μM CdCl2. Moreover, using a cell-permeable NO specific fluorescent probe by confocal laser scanning microscopy (CLSM), we studied how Cd affects NO root content. Data indicate that Cd altered both Arabidopsis root morphology and NO distribution. The pollutant increased the length and density of lateral roots (LRs), whereas reduced the primary root (PR) length. In addition, Cd increased NO levels in the LRs and decreased it in the PR. PTS1 signal was changed by Cd only in the PR, showing a decrease of peroxisomes distribution and intensity. Furthermore, biochemical assays indicated that Cd negatively affects CAT activity. Our findings suggest that Cd affects H2O2 metabolism and NO content by acting on peroxisomes activity, leading to root architecture alteration and confirming the role of these organelles in the mechanisms of response against this pollutant.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
