Effects of cadmium toxicity on growth and biochemical properties of chickpea (Cicer arietinum L.)

Growing concerns about climate change require more knowledge regarding plant-environment interaction and more importantly how our economically important crops are adopting diverse heavy metal pollutants to confer food security. The effect of cadmium (Cd) on the growth and biochemical features of chickpea ( Cicer arietinum L.) plants grown in sand culture was evaluated to better understand heavy metal toxicity and crop adaptability during the present study. Four different concentrations of Cd namely 250 µM, 500 µM, 750 µM and 1000 µM along with control were considered at 7 days, 14 days, and 21 days of treatment on selected Chickpea var. BARI Chola 5. Growth was determined by measuring fresh weight and height. Several biochemical tests (e.g. protein, proline, antioxidant enzymes, and lipid peroxidation) were conducted using root samples mainly in addition to leaves for chlorophyll and sugar measurements. Due to Cd application, chickpea plants exhibited stunted growth with chlorosis, and plant height and weight were reduced compared to control-treated plants. Also, Cd toxicity resulted in a reduction in chlorophyll a, chlorophyll b, and total chlorophyll in the leaves of chickpeas. Though exposure of Cd at 7 days of treatment showed variable response in reducing and total sugar content; both the 14 and 21 days of treatment exerted a depletion. Cd stress increased proline content from 7 to 21 days of treatment in the chickpea roots. However, total protein content was found to be declined in Cd-treated chickpea roots compared to control. Cd treatment caused an increase in peroxidase and catalase activity whereas membrane damage rate decreased with increasing concentration of Cd. The present study demonstrated how crop plants like chickpeas are physically and biochemically adapted to various concentrations of Cd stress with a time-series experiment and their potential to tolerate Cd at different stages of their growth.