Plants can suffer ammonium (NH4 + ) toxicity, particularly when NH4 + is supplied as the sole nitrogen source. However, our knowledge about the underlying mechanisms of NH4 + toxicity is still largely unknown. Lemna minor, a model duckweed species, can grow well in high NH4 + environment but to some extent can also suffer toxic effects. | Transcriptomic and physiological analysis of common duckweed Lemna minor responses to NH4 toxicity