Lanthanum supplementation with abscisic acid modulates rhizosphere dynamics through changes in nitric oxide synthesis in wheat.

Lanthanum (La), a rare earth element (REE) found its wide applications in the agricultural land practices. Utilization of La as a fertilizer is based on its concentration for staple crops, including wheat (Triticum aestivum). We have investigated the role of a beneficial dose of La (60 μM) along with ABA (10 μM) in improving wheat root dynamics and defense systems (ascorbate-glutathione pathway, secondary metabolites, and nitric oxide (NO) biosynthesis). Co-application of La60 and ABA significantly enhanced all the root dynamic attributes along with defense systems and reduced production of reative oxygen species (ROS). The use of the NO inhibitor c-PTIO [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxy-3-oxide], proved that the impact of co-application of La60 and ABA on root growth dynamics was mediated by NO biosynthesis. Thus, this study could work as the base to understand the dose-dependent behavior of La in plants, offering valuable implications for enhancing crop resilience, optimizing agricultural practices, and mitigating the detrimental effects of La toxicity on wheat root development. This research gives a comprehensive insight into root dynamics influenced by ABA with La dose optimisations in wheat.