Elevated CO₂ mitigates the effects of cadmium stress on vegetable growth and antioxidant systems

Abstract

Prior to the industrial revolution, the concentration of CO 2 , one of the main greenhouse gases, was 280 μmol/mol; today, it is over 400 μmol/mol (Sekhar et al. 2023). The continuous increase in CO 2 concentration is one of the primary challenges that need to be addressed in the global response to climate change. In addition to raising global temperatures, eCO 2 concentrations also affect other environmental factors and directly or indirectly affect plant growth, physiology and other responses in many ways, including those of vegetables. Although CO 2 is one of the most commonly used fertilisers in agricultural glasshouse facilities, the effects of eCO 2 levels on the growth of vegetables, such as tomatoes (Solanum lycopersicum L.) (Halpern et al. 2018), celery (Apium graveolens L.) (Liu et al. 2020), kale (Brassica oleracea L.) (Chowdhury et al. 2021), cucumbers (Cucumis sativus L.) (Song et al. 2020), peppers (Capsicum annuum L.) (Kumari et al. 2019) and aubergines (Solanum melongena L.) (Xu et al. 2021), vary depending on the vegetable species and other factors. Cadmium (Cd) is a non-essential heavy metal element for plant growth and is highly mobile and readily absorbed by plants (Zulfiqar et al. 2022). At a certain level, Cd contamination can be toxic to plants, inhibiting plant growth and various physiological responses, including cellular ultrastructure (Alves et al. 2020), photosynthesis (Rafique et al. 2019) and antioxidant properties (Taie et al. 2019).However, the effects of eCO 2 and heavy metal stress conditions on plant growth and physiology are less