title: Mild ammonium stress increases chlorophyll content in Arabidopsis thaliana.
abstract: Nitrate (NO3(-)) and ammonium (NH4(+)) are the main forms of nitrogen available in the soil for plants. Excessive NH4(+) accumulation in tissues is toxic for plants and exclusive NH4(+)-based nutrition enhances this effect. Ammonium toxicity syndrome commonly includes growth impairment, ion imbalance and chlorosis among others. In this work, we observed high intraspecific variability in chlorophyll content in 47 Arabidopsis thaliana natural accessions grown under 1 mM NH4(+) or 1 mM NO3(-) as N-source. Interestingly, chlorophyll content increased in every accession upon ammonium nutrition. Moreover, this increase was independent of ammonium tolerance capacity. Thus, chlorosis seems to be an exclusive effect of severe ammonium toxicity while mild ammonium stress induces chlorophyll accumulation.
authors: a Department of Plant Biology and Ecology ; University of the Basque Country UPV/EHU ; Bilbao , Spain.
authors: Joseba
authors: J
authors: Sanchez-Zabala
authors: Carmen
authors: C
authors: González-Murua
authors: Daniel
authors: D
authors: Marino
mesh_terms: D000222:Adaptation, Physiological; D064751:Ammonium Compounds / Q000378:metabolism / Q000633:toxicity*; D017360:Arabidopsis / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010935:Plant Diseases; D013312:Stress, Physiological
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D002734:Chlorophyll; D009584:Nitrogen
keywords: Arabidopsis thaliana; Chl, chlorophyll; N, nitrogen; NH4+, ammonium; NO3−, nitrate; SPAD; ammonium; chlorophyll; natural variation; nitrogen nutrition