The impact of acid rain on cadmium phytoremediation in sunflower (Helianthus annuus L.)

Jiawen Zhong; Yeqing Liu; Xinheng Chen; Zihao Ye; Yongtao Li; Wenyan Li

doi:10.1016/j.envpol.2023.122778

The impact of acid rain on cadmium phytoremediation in sunflower (Helianthus annuus L.)

Environ Pollut. 2024 Jan 1;340(Pt 2):122778. doi: 10.1016/j.envpol.2023.122778. Epub 2023 Oct 18.

Authors

Jiawen Zhong¹, Yeqing Liu¹, Xinheng Chen¹, Zihao Ye¹, Yongtao Li², Wenyan Li³

Affiliations

¹ College of Natural Resources and Environment, Joint Institute for Environmental Research & Education, South China Agricultural University, Guangzhou 510642, China.
² College of Natural Resources and Environment, Joint Institute for Environmental Research & Education, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Arable Land Conservation (South China), MOA, South China Agricultural University, Guangzhou 510642, China; Guangdong Province Key Laboratory for Land Use and Consolidation, South China Agricultural University, Guangzhou 510642, China.
³ College of Natural Resources and Environment, Joint Institute for Environmental Research & Education, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Arable Land Conservation (South China), MOA, South China Agricultural University, Guangzhou 510642, China; Guangdong Province Key Laboratory for Land Use and Consolidation, South China Agricultural University, Guangzhou 510642, China. Electronic address: lily1984191@scau.edu.cn.

PMID: 37863250
DOI: 10.1016/j.envpol.2023.122778

Abstract

Sunflower is an ideal crop for phytoremediation of cadmium-contaminated farmland, as it brings economic benefits while conducting soil remediation. Due to industrial emissions and car exhaust, Cd contaminated areas are often accompanied by acid rain. However, the impact of acid rain on the Cd remediation capacity of sunflowers and its potential influencing factors are unclear. An experiment was manipulated to elucidate the effects of Cd concentration (0,10,50,100 μmol/L) and acid rain (pH 4.0) on the phytoremediation ability of sunflowers, in which the properties of them were explored. The results indicated that Cd stress is the main factor affecting the growth of sunflowers. Without AR, Cd treatment decreased sunflower biomass by 67.5-85.6%. Under AR, Cd treatment decreased sunflower biomass 53.9-86.4%. Compared without AR, the relative chlorophyll content with AR increased by 22.3-23.1%, while the YII with AR decreased by 6.5-20.0%. There was an interaction between acid rain and Cd stress on antioxidant enzyme activity. With AR, CAT activity at 0 μmol/L Cd treatment increased by 25.6%, compared without AR. Whether there is acid rain or not, the POD and SOD activities were increased at 10, 50 μmol/L Cd treatment, but they were decreased at 100 μmol/L Cd treatment. Among them, acid rain exacerbated the impact of POD activity (decreased by 31.4%) at 100 μmol/L Cd treatment and SOD activity (decreased by 15.1%) at 50 μmol/L Cd treatment, compared without AR. In this experiment, the phytoremediation capacity of sunflowers mainly depended on the concentration of Ca in the leaves and their antioxidant capacity. Acid rain enhanced 77.5% the total Cd accumulation at 10 μmol/L Cd treatment, compared without AR. Acid rain exacerbated the damage of Cd to the chloroplast structure of sunflowers, and reduced the accumulation of starch particles. The study findings may be useful for improving the phytoremediation of Cd-contaminated soil.

Keywords: Acid rain; Antioxidant enzyme; Cadmium; Chlorophyll fluorescence; Phytoremediation; Sunflower.

MeSH terms

Acid Rain*
Antioxidants
Biodegradation, Environmental
Cadmium / analysis
Cadmium / toxicity
Helianthus*
Soil / chemistry
Soil Pollutants* / analysis
Soil Pollutants* / toxicity
Superoxide Dismutase

Substances

Cadmium
Acid Rain
Antioxidants
Soil Pollutants
Soil
Superoxide Dismutase