Open Access

ARTICLE

Differential Effects of Ammonium and Nitrate on Growth Performance of Glechoma longituba under Heterogeneous Cd Stress

by Yanwei Feng, Wen Lei, Rui Gu, Ping Zhao, Shijun Ni, Ningfei Lei

1 College of Earth Sciences, Chengdu University of Technology, Chengdu, 610101, China
2 College of Landscape Architecture, Sichuan Agricultural University, Chengdu, 610101, China
3 College of Environment, Chengdu University of Technology, Chengdu, 610101, China
4 Geological Party 105, Guizhou Provincial Bureau of Geology and Mineral Exploration and Development, Guiyang, 550018, China

* Corresponding Authors: Shijun Ni. Email: ; Ningfei Lei. Email:

Phyton-International Journal of Experimental Botany 2020, 89(3), 667-679. https://doi.org/10.32604/phyton.2020.010160

Received 14 February 2020; Accepted 27 March 2020; Issue published 22 June 2020

Abstract

Water, minerals, nutrients, etc., can be shared by physiological integration among inter-connected ramets of clonal plants. Nitrogen plays an important role in alleviating cadmium (Cd) stress for clonal plants. But how different forms of nitrogen affect growth performance of clonal plants subjected to heterogeneous Cd stress still remains poorly understood. A pot experiment was conducted to investigate the differential effects of ammonium and nitrate on growth performance of Glechoma longituba under heterogeneous Cd stress. In the experiment, parent ramets of Glechoma longituba clonal fragments were respectively supplied with modified Hoagland solution containing 7.5 mM ammonium, 7.5 mM nitrate or the same volume of nutrient solution without nitrogen. Cd solution with different concentrations (0, 0.1 or 2.0 mM) was applied to offspring ramets of the clonal fragments. Compared with control (N-free), nitrogen addition to parent ramets, especially ammonium, significantly improved antioxidant capacity [glutathione (GSH), proline (Pro), peroxidase (POD,) superoxide dismutase (SOD) and catalase (CAT)], PSII activity [maximum quantum yield of PSII (F_v/F_m) and effective quantum yield of PSII (ΦPSII)], chlorophyll content and biomass accumulation of the offspring ramets suffering from Cd stress. In addition, negative effects of nitrate on growth performance of whole clonal fragments were observed under Cd stress with high concentration (2.0 mM). Transportation or sharing of nitrogen, especially ammonium, can improve growth performance of clonal plants under heterogeneous Cd stress. The experiment provides insight into transmission mechanism of nitrogen among ramets of clonal plants suffering from heterogeneous nutrient supply. Physiological integration might be an important ecological strategy for clonal plants adapting to heterogeneous environment stress conditions.

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