Physio-Biochemical Indexes as Indicators of Cadmium Tolerance in <i>Brassica napus</i> L. Cultivars
Yu Qiu,
Shuhe Wei,
Jie Zhan,
Brett H. Robinson,
Lidia Skuza,
Jianming Xue,
Huiping Dai,
Li Zhan,
Ziyang Tang
Affiliations
Yu Qiu
College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-Resources, Qinling-Bashan Mountains Bioresources Comprehensive Development C.I.C., State Key Laboratory of Biological Resources and Ecological Environment Jointly Built by Qinba Province and Ministry, Shaanxi University of Technology, Hanzhong 723001, China
Shuhe Wei
Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
Jie Zhan
Health Management Department, Liaoning Vocational College of Medicine, Shenyang 110101, China
Brett H. Robinson
School of Physical and Chemical Sciences, University of Canterbury, Christchurch 8041, New Zealand
Lidia Skuza
Institute of Biology, Centre for Molecular Biology and Biotechnology, University of Szczecin, 71-415 Szczecin, Poland
Jianming Xue
New Zealand Forest Research Institute (Scion), P.O. Box 29237, Christchurch 8440, New Zealand
Huiping Dai
College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-Resources, Qinling-Bashan Mountains Bioresources Comprehensive Development C.I.C., State Key Laboratory of Biological Resources and Ecological Environment Jointly Built by Qinba Province and Ministry, Shaanxi University of Technology, Hanzhong 723001, China
Li Zhan
College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-Resources, Qinling-Bashan Mountains Bioresources Comprehensive Development C.I.C., State Key Laboratory of Biological Resources and Ecological Environment Jointly Built by Qinba Province and Ministry, Shaanxi University of Technology, Hanzhong 723001, China
Ziyang Tang
College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-Resources, Qinling-Bashan Mountains Bioresources Comprehensive Development C.I.C., State Key Laboratory of Biological Resources and Ecological Environment Jointly Built by Qinba Province and Ministry, Shaanxi University of Technology, Hanzhong 723001, China
Cadmium (Cd) is a non-essential heavy metal and a pervasive pollutant in agricultural soils. Despite numerous studies investigating Cd accumulation and tolerance in plants, there is a lack of systematic analysis of how various physio-biochemical indexes respond to Cd toxicity, particularly their indicative role in plant tolerance mechanisms. A pot experiment was conducted in greenhouse to assess the differences in Cd accumulation and tolerance among three Brassica napus L. cultivars (‘Hanyou 2’, ‘Hanyou 3’, and ‘Hanyou 16’) under the treatments of CK (0.18 mg kg−1 in soil), T1 (2.18 mg kg−1 in soil), T2 (4.18 mg kg−1 in soil), and T3 (8.18 mg kg−1 in soil). All three cultivars exhibited high tolerance indexes (TIs) and strong Cd tolerance when exposed to a Cd concentration of 2.18 mg kg−1 in soil (T1). There were significant positive correlations between TI and chlorophyll a (Chla), chlorophyll b (Chlb), carotenoids (Car), net photosynthetic rate (Pn), transpiration rate (Tr), and activities of antioxidant enzymes and non-enzymatic antioxidants such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione (GSH), and ascorbic acid (ASA), while negatively correlating with intercellular CO2 concentration (Ci) and malondialdehyde (MDA) content. These findings underscore the significant indicative role of these physio-biochemical indexes in elucidating Cd tolerance mechanisms in B. napus and may be used in breeding programs to develop cultivars with a high Cd-tolerance but low Cd uptake profile. However, this was a pot experiment only. Field experiments might be more useful in the future.
