TY - JOUR
T1 - Respiratory burst oxidases and apoplastic peroxidases facilitate ammonium syndrome development in Arabidopsis
AU - Podgórska, Anna
AU - Burian, Maria
AU - Dobrzyńska, Katarzyna
AU - Rasmusson, Allan G.
AU - Szal, Bożena
PY - 2021/1
Y1 - 2021/1
N2 - Ammonium-nitrogen (NH4+) nutrition is linked to metabolic over-reduction for plants. The characteristic symptom of sole NH4+ nutrition is growth suppression, signifying this condition as the ammonium syndrome. In the present study, we investigated the mechanism of perception of high NH4+ conditions in Arabidopsis thaliana plants by examining apoplastic reactive oxygen species (ROS) metabolism. Major enzyme activity and a special pattern of expression of NADPH-dependent respiratory burst oxidases (RBOH) was found in Arabidopsis individuals cultured under NH4+ as the sole nitrogen source. This oxidative burst is independent of RBOHD/F expression and does not activate typical intracellular signalling pathways. In addition, elevated superoxide dismutase and apoplastic secretory peroxidase activities contributed to hydrogen peroxide (H2O2) accumulation in plants exposed to NH4+ nutrition. Consequently, higher H2O2 contents were determined in the extracellular space and were localised cytochemically. H2O2 is a substrate for cell wall cross-linking peroxidases, which showed enhanced activity in the presence of NH4+. Increase of cell wall polymerisation, could in turn inhibit cell elongation and slow down growth, as observed under NH4+ toxicity.
AB - Ammonium-nitrogen (NH4+) nutrition is linked to metabolic over-reduction for plants. The characteristic symptom of sole NH4+ nutrition is growth suppression, signifying this condition as the ammonium syndrome. In the present study, we investigated the mechanism of perception of high NH4+ conditions in Arabidopsis thaliana plants by examining apoplastic reactive oxygen species (ROS) metabolism. Major enzyme activity and a special pattern of expression of NADPH-dependent respiratory burst oxidases (RBOH) was found in Arabidopsis individuals cultured under NH4+ as the sole nitrogen source. This oxidative burst is independent of RBOHD/F expression and does not activate typical intracellular signalling pathways. In addition, elevated superoxide dismutase and apoplastic secretory peroxidase activities contributed to hydrogen peroxide (H2O2) accumulation in plants exposed to NH4+ nutrition. Consequently, higher H2O2 contents were determined in the extracellular space and were localised cytochemically. H2O2 is a substrate for cell wall cross-linking peroxidases, which showed enhanced activity in the presence of NH4+. Increase of cell wall polymerisation, could in turn inhibit cell elongation and slow down growth, as observed under NH4+ toxicity.
KW - Ammonium toxicity
KW - Apoplastic reactive oxygen species
KW - Cell wall peroxidase
KW - Cell wall polymerisation
KW - Respiratory burst oxidase homolog
KW - Stress perception
UR - http://www.scopus.com/inward/record.url?scp=85092202151&partnerID=8YFLogxK
U2 - 10.1016/j.envexpbot.2020.104279
DO - 10.1016/j.envexpbot.2020.104279
M3 - Article
AN - SCOPUS:85092202151
SN - 0098-8472
VL - 181
JO - Environmental and Experimental Botany
JF - Environmental and Experimental Botany
M1 - 104279
ER -