IAA-loaded layered double hydroxides nanoparticles improve the rooting efficiency of adventitious roots in Pyrus...

Pear is widely planted, with high nutritional and commercial value. Excellent pear cultivars' traits are kept for revenue creation mostly by grafting. Pyrus betulaefolia Bunge is globally recognized as a robust and stress-resistant rootstock. Clonal propagation of P. betulaefolia, which relies on the induction of adventitious roots (ARs) from stem cuttings, is a critical step in breeding programs. However, the inherently low capacity of this species to form AR poses a major challenge to efficient propagation. Indole-3-acetic acid (IAA) plays a key role in AR formation, but its practical application is limited due to its rapid degradation. In this study, we described the use of layered double hydroxides (LDH) as an effective delivery system for IAA, enhancing its stability and utilization when applied topically to P. betulaefolia cuttings, thereby improving AR formation. Comprehensive metabolic and functional analyzes revealed that LDH-IAA significantly increased the rooting rate compared to IAA alone. The optimal concentration of LDH-IAA was 4 mg/L, at which the rooting rate reached 79.2%, 1.5 times higher than that of the same concentration of IAA without LDH. This work highlights the practicality of a slow-release strategy for bioactive compounds to achieve more effective plant growth regulation and offers insights to the sustainable use of plant hormones.