Abstract
To clarify the mechanism of submerged macrophytes disappearance and supply the necessary theory for the vegetation restoration in eutrophic Lake Taihu, effects of the moderate nutrients concentration, excessive NH<sub>4</sub><sup>+</sup>－N and PO<sub>4</sub><sup>3－</sup>－P in the water column on the antioxidant defense system in submerged macrophyte, <i>Vallisneria asiatica</i>, were studied with the 20－day aquarium experiments. The results showed that the moderate concentration of nutrients can promote the metabolism of <i>V. asiatica</i>. Either excessive NH<sub>4</sub><sup>+</sup>－N or PO<sub>4</sub><sup>3－</sup>－P could cause the oxidative stress to cells of <i>V. asiatica</i>, expressed as decreased contents of chlorophyll a (Chl.a) and protein, and the enhancement of catalase (CAT) activities in leaves of <i>V. asiatica</i>. In addition, 0.6 mg・<i>l</i><sup>－1</sup> of PO<sub>4</sub><sup>3－</sup>－P caused more oxidative damages to <i>V. asiatica</i> than 3.5 mg・<i>l</i><sup>－1</sup> NH<sub>4</sub><sup>+</sup>－N. The results indicated that the antioxidative protection mechanisms could be activated but still could not prevent the damage of the metabolism system in <i>V. asiatica</i> exposed to either excessively high concentrations of NH<sub>4</sub><sup>+</sup>－N or PO<sub>4</sub><sup>3－</sup>－P. Therefore, it is necessary to establish a dual control strategy of N and P for the restoration of <i>V. asiatica</i> in eutrophic Lake Taihu.
| Translated title of the contribution | Metabolic and Antioxidant Responses of <i>Vallisneria asiatica</i> to Different Concentrations of Dissolved Inorganic Nitrogen and Phosphorus |
|---|---|
| Original language | Japanese |
| Pages (from-to) | 105-112 |
| Number of pages | 8 |
| Journal | 日本水処理生物学会誌 |
| Volume | 50 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2014 |