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Acta Prataculturae Sinica ›› 2021, Vol. 30 ›› Issue (7): 139-147.DOI: 10.11686/cyxb2020259

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Metal accumulation characteristics and physiological response of Kummerowia striata to manganese stress

Xin-hang LI(), Ze-hua XIAO, Xue-shao KUANG, Wu-min WANG, Liang-yu LUO, Wen-sheng LIU()   

  1. College of Life Science and Technology,Central South University of Forestry and Technology,Changsha 410004,China
  • Received:2020-06-02 Revised:2020-08-19 Online:2021-07-20 Published:2021-06-03
  • Contact: Wen-sheng LIU

Abstract:

This research studied the tolerance mechanism of plants to manganese stress. Individual plants of Kummerowia striata were collected from localities contaminated or not contaminated by heavy metals and cultivated under different concentrations of manganese [0 (Control), 1000, 5000, 10000, 15000, 20000 μmol·L-1]. The effects of manganese stress on the phenotype, physiological and biochemical features, and manganese accumulation characteristics of K. striata from these two sources were evaluated. It was found that, as the concentration of Mn increased: 1) The root dry weight, shoot dry weight, and root∶shoot ratio of K. striata from both localities decreased; when the concentration of Mn was in the range 5000-20000 μmol·L-1, compared with the Control, the shoot and root dry weight of plants from the contaminated locality decreased by 4.34%-27.71% and 19.00%-66.06%, respectively; while the shoot and root dry weight for plants from the uncontaminated locality decreased by 16.33%-49.77% and 27.90%-77.54%, respectively. 2) The contents of chlorophyll, soluble sugar and proline and the activities of superoxide dismutase and peroxidase in leaves of K. striata from the two localities showed a pattern of initial increase and then decrease with increasing Mn exposure, while the content of soluble protein gradually decreased and the content of malondialdehyde gradually increased. 3) The Mn content of the roots, stems, and leaves of K. striata from both localities increased. When grown at the Mn concentration of 20000 μmol·L-1, the Mn content of K. striata sourced from the contaminated and uncontaminated areas was 16.53 and 13.41 times than that of the Control, respectively. Therefore, the Mn accumulation capacity and Mn tolerance of the K. striata from the contaminated locality are higher than in plants sourced from the uncontaminated locality. High activities of antioxidant enzymes appear to be an important physiological mechanism of K. striata tolerance to high Mn stress.

Key words: Mn stress, heavy metal contaminated area, Kummerowia striata, physiological and biochemical features, accumulation characteristics