Variability in cadmium stress tolerance among four maize genotypes: Impacts on plant physiology, root morphology, and chloroplast microstructure

Tingting An; Qiqiang Kuang; Yujie Wu; Yamin Gao; Yi Zhang; Bede S Mickan; Bingcheng Xu; Suiqi Zhang; Xiping Deng; Yinglong Chen

doi:10.1016/j.plaphy.2023.108135

Variability in cadmium stress tolerance among four maize genotypes: Impacts on plant physiology, root morphology, and chloroplast microstructure

Plant Physiol Biochem. 2023 Dec:205:108135. doi: 10.1016/j.plaphy.2023.108135. Epub 2023 Nov 7.

Authors

Tingting An¹, Qiqiang Kuang², Yujie Wu², Yamin Gao², Yi Zhang³, Bede S Mickan⁴, Bingcheng Xu⁵, Suiqi Zhang⁵, Xiping Deng⁵, Yinglong Chen⁶

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China; College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China; The UWA Institute of Agriculture & School of Agriculture and Environment, The University of Western Australia, Perth, 6009, Australia.
² State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China; College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China.
³ College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, China.
⁴ The UWA Institute of Agriculture & School of Agriculture and Environment, The University of Western Australia, Perth, 6009, Australia.
⁵ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China.
⁶ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China; The UWA Institute of Agriculture & School of Agriculture and Environment, The University of Western Australia, Perth, 6009, Australia. Electronic address: yinglong.chen@uwa.edu.au.

PMID: 37979572
DOI: 10.1016/j.plaphy.2023.108135

Abstract

Cadmium (Cd) is detrimental to both plants and humans. Maize (Zea mays L.) genotypes exhibit variations in Cd accumulations. This study examined variations in Cd accumulation and tolerance among four maize genotypes with contrasting root morphology. The four maize genotypes were cultivated in a semi-hydroponic system with three Cd concentrations (0, 10, 20 μmol L^-1). The effects of Cd on plant growth and physiology were assessed 39 days after transplanting. Results showed that root characteristics were positively correlated with root Cd accumulation and the bioconcentration factor under Cd20 treatment. Genotypes Shengrui999 and Zhengdan958 exhibited higher total Cd content than Xundan29 and Zhongke11 under Cd20 conditions. Cd toxicity led to membrane degradation of chloroplast mesophyll cells, loosening and swelling of grana lamella, and reduced starch reserves. The greater tolerance of Shengrui999 and Zhengdan958 was contributed to factors such as root biomass, shallower root depth, higher Cd content, accumulation of osmolyte such as soluble protein, antioxidant activities such as catalase (CAT), and the presence of phytohormone gibberellic acid. The study establishes a link between root morphology, Cd accumulation, and tolerance in maize plants, as demonstrated by the higher Cd accumulation and shallower root system in Cd-tolerant genotypes. This research provides a foundation for breeding maize cultivars better suited for adaptation to moderate Cd-contaminated environments.

Keywords: Cd bioconcentration and translocation; Energy dispersive X-ray microanalysis; Maize; Root parameters; Stress tolerance.

MeSH terms

Cadmium* / metabolism
Chloroplasts / metabolism
Humans
Plant Breeding
Plant Physiological Phenomena
Plant Roots
Soil Pollutants* / metabolism
Zea mays

Substances

Cadmium
Soil Pollutants