Calcium Nanoparticles and Abscisic Acid Improve Drought Tolerance, Mineral Nutrients Uptake and Inhibitor-Mediated Photosystem II Performance in Brassica Napus

Plant yield is severely hampered by drought, affirming the urgent need to develop strategies to improve plant growth and drought tolerance. The synergistic application of ABA and calcium nanoparticles (Ca-NPs) has emerged as a promising approach for sustainable crop production and improved resistance to abiotic stress, although the underlying mechanism for foliar application of growth regulator ABA and Ca-NPs in regulating plant growth and drought tolerance in rapeseed (Brassica napus L.) remains poorly understood. To address this knowledge gap, the current study was conducted to investigate the protective role of 100-µM ABA and 100 ppm Ca-NPs in alleviating the drought stress (15