An Integral Hybrid Polymeric Biostimulant to Cope With Drought Stress in Bread Wheat

Drought-induced water scarcity is a pressing challenge in agriculture, as it is exacerbated by climate change. Superabsorbent polymers (SAPs) have emerged as effective tools to mitigate drought stress by improving soil water retention and nutrient delivery. However, the environmental concerns surrounding synthetic SAPs necessitate the development of sustainable, biobased alternatives. This study evaluates the efficacy of two innovative biobased SAPs, alginate-based (SAP) and alginate-chitosan-based (BioSAP), compared to a commercial polyacrylate (PAK) in enhancing drought resilience in bread wheat (Triticum aestivum). Physiological parameters, including Turgor Loss Point (TLP), leaf water potential, stomatal conductance, electrolyte leakage, and proline content, were monitored under well-watered and drought-stressed conditions. The results demonstrate that BioSAP significantly improved drought tolerance by enhancing osmotic adjustment, delaying TLP. BioSAP-treated plants exhibited superior resilience, with reduced cell damage and moderated proline accumulation, indicating efficient stress tolerance. The dual functionality of BioSAP, combining water retention with biostimulant properties, promoted metabolic adaptations, including solute mobilization and cell wall rigidity. These findings highlight the potential of biobased SAPs, particularly BioSAP, as a sustainable alternative for drought stress mitigation, contributing to environmentally friendly and efficient agricultural practices.