Seed priming with nitric oxide and foliar glycine betaine application mitigates Cadmium toxicity and improves wheat...

Cadmium (Cd) contamination of agricultural soils, from industrial and phosphate fertilizer inputs, poses a major threat to wheat production and food safety worldwide. A pot experiment was performed to study the effects of nitric oxide (NO) seed priming and foliar application of glycine betaine (GB) on morphological, physiological, and yield attributes of wheat under Cd stress. Cadmium stress significantly reduced the physiological, morphological, enzymatic, and non-enzymatic activities, chlorophyll contents, yield, and its related traits such as the number of spikes, spike length, awn length, total number of spikelets per plant, fertile spikelets, grain length, rachis length, 1000 grain weight, and total grain weight, whereas, significant increase was observed in the levels of reactive oxygen species (ROS) such as H₂O₂, along with Cd accumulation in shoots compared with the control conditions. However, co-application of NO seed priming and foliar applications of GB significantly improved antioxidant enzyme activities, enhanced photosynthetic activity, increased the accumulation of total soluble proteins (TSP), proline content, and improved the yield components of wheat plants under Cd stress. Our results reveal that the coordinated use of NO seed priming and GB foliar application mitigates Cd phytotoxicity, enhances wheat's defensive metabolism, and significantly improves yield. This strategy presents a cost-effective, practical phyto-management approach to cultivate wheat in Cd-affected soils, contributing to both land remediation and food security.