Insight into Cistus salviifolius extract for potential biostimulant effects in modulating cadmium-induced stress in sorghum plant

The main aim of the current study was to investigate the role of Cistus salviifolius leaves extract (CSE) in alleviating the toxic effect of cadmium (Cd) in sorghum (Sorghum bicolor) plants. The plants exposed to Cd (200 µM) exhibited limited growth, reduced biomass, and chlorophyll content compared to unstressed ones. Nevertheless, supplementation of CSE restored the negative effect of Cd and increased biomass and pigment content. CSE also increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), isocitrate dehydrogenase (ICDH), glutathione peroxidase (GPx), glutathione reductase (GR), and Glutathione-S-Transferase (GST). Furthermore, supplementation of CSE decreased lipid peroxidation and further increased the content of soluble sugar and amino acid. We also found that CSE has a promising effect in modulating the perturbations of carbon and nitrogen metabolism in sorghum plants under Cd stress by examining several carbon-nitrogen enzyme activities: phosphoenolpyruvate carboxylase (PEPC), malate dehydrogenase (NAD-MDH), glutamine synthase (GS), glutamate dehydrogenase (GDH), and aspartate aminotransferase (AAT). Overall, our results confirm that the application of CSE can be a promising mechanism to overcome the negative effects of Cd stress in sorghum plants.