Abstract

Restoration of acidic/highly contaminated sites is particularly challenging, and thus practitioners may require targeting stress tolerant species for restoration. Phytoremediation technology is efficient, eco-friendly and cost-effective, and one of the candidate species for phytoremediation of highly acidic mine wastelands is Neyraudia reynaudiana. However, the threshold of acidity above which it becomes inhibitory for emergence and establishment of the species as well as the effect on cellular structure are still unclear. In this study, we specifically aimed to understand how acid stress may affect early life stage processes such as seed germination, and seedling growth and cellular integrity. This was achieved by assessing germination capacity, germination potential and rate, biomass production and plasma membrane integrity in root tips after exposing seeds to a gradient of acid stress (pH 5.5, 4.5, 3.5 and control). The results showed that acid treatment with pH 3.5 adversely affected seed germination and seedling growth of N. reynaudiana, and severely damaged the root apex plasma membrane and the subcellular mitochondria and chloroplasts in the epicotyl. The germination potential and germination rate of seeds treated with acid solution with pH 4.5 were significantly higher by 23-29 % and 5-10 % than those of other acid stress treatments, while the effects of acid treatments with pH 4.5 and 5.5 on root growth and biomass of N. reynaudiana germinants were subtle. It can be concluded that N. reynaudiana tolerates acidity as low as pH 4.5 through maintaining plasma membrane integrity and subcellular structure. From phytoremediation viewpoint, sowing seeds of N. reynaudiana on acidic mine wastes with pH >= 4.5 would result in early establishment success.

Keywords

Cell relative activity; Epicotyl elongation; Germination characteristics; Phytoremediation; Restoration ecology

Published in

Flora
2020, Volume: 263, article number: 151549
Publisher: ELSEVIER GMBH

SLU Authors

• Tigabu, Mulualem

  • Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
    
  • Fujian Agriculture and Forestry University

UKÄ Subject classification

Ecology
Botany


Publication identifier

DOI: https://doi.org/10.1016/j.flora.2020.151549

Permanent link to this page (URI)

https://res.slu.se/id/publ/104875