Effect of fertilizers on Cd accumulation and subcellular distribution of two cosmos species (Cosmos sulphureus and Cosmos bipinnata)

ABSTRACT

Addition of fertilizer amendments is regarded as an ideal approach to enhancing phytoextraction. However, there is little information available on the influence of common fertilizers on Cd accumulation of two newly reported Cd accumulators, Cosmos sulphureus and Cosmos bipinnata (C. sulphureus and C. bipinnata). The effects of N (CO(NH₂)₂), NP (CO(NH₂)₂ + Ca(H₂PO₄)₂), and NPK (CO(NH₂)₂ + Ca(H₂PO₄)₂ + KCl) fertilizers on Cd accumulation and subcellular distribution of C. sulphureus and C. bipinnata were studied in a 70-d pot experiment. The results showed that Cd uptake of C. sulphureus and C. bipinnata with NPK fertilizer was significantly higher than control, N, and NP fertilizers, especially 3.8- and 4.7-fold higher than control (p < 0.05). Compared with C. bipinnata, C. sulphureus achieved higher biomass and Cd uptake in aboveground parts under fertilizer treatments, especially NPK fertilizer. The Cd subcellular distribution revealed that segregation of Cd to Cd-rich granules (MRG) might play an important role in Cd detoxification in both species. C. sulphureus is more likely than C. bipinnata to separate the Cd in MRG and reduce the partition in the heat-denatured protein fraction, especially with NPK fertilizer. Therefore, C. sulphureus combined with NPK fertilizers could be an effective method to remediate Cd-polluted farmland soils in China.

KEYWORDS:

• Cadmium
• Cosmos bipinnata
• Cosmos sulphureus
• fertilizer
• phytoremediation

Acknowledgments

We thank Alex Boon, PhD, from Liwen Bianji, Edanz Editing China (www.liwenbianji.cn/ac), for editing the English text of a draft of this manuscript.

Additional information

Funding

This research was financially supported by the National Natural Science Foundation of China (NSFC Nos. 41771509, 41771510, 41201312, 41271478), Science and Technology Service Network Initiative (KFJ-EW-STS-014), Special Project for Institute of Chinese Academic Sciences (TSYJS01) and Phytoremediation Project of Farmland Polluted by Heavy Metal in Jiyuan County (JGZJ-2015152-01).