Mild ammonium stress increases chlorophyll content in Arabidopsis thaliana

• Published in: Plant signaling & behavior Vol. 10; no. 3; p. e991596
• Main Authors: Sanchez-Zabala, Joseba, González-Murua, Carmen, Marino, Daniel
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01-01-2015
• Subjects: Adaptation, Physiological; ammonium; Ammonium Compounds - metabolism; Ammonium Compounds - toxicity; Arabidopsis - metabolism; Arabidopsis thaliana; chlorophyll; Chlorophyll - metabolism; natural variation; Nitrates - metabolism; Nitrogen - metabolism; nitrogen nutrition; Plant Diseases; Short Communication; SPAD; Stress, Physiological; Arabidopsis thaliana; N, nitrogen; NH4+, ammonium; SPAD; natural variation; ammonium; chlorophyll; nitrogen nutrition; NO3−, nitrate; Chl, chlorophyll
• ISSN: 1559-2316; 1559-2324; 1559-2324
• DOI: 10.4161/15592324.2014.991596

Nitrate (NO
3
−
) and ammonium (NH
4
+
) are the main forms of nitrogen available in the soil for plants. Excessive NH
4
+
accumulation in tissues is toxic for plants and exclusive NH
4
+
-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 NH
4
+
or 1 mM NO
3
−
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.