Ultrasound-enhanced seed hydration: impacts on seedling vigor, gene expression and absorption kinetics in maize, bean...

Various methods have been explored to improve seed hydration, reduce hydration time and improve germination rates, such as seed priming methods and non-invasive technologies like ultrasound. Several reports have highlighted ultrasound technology's positive effects on germination and seedling development by enhancing water absorption. However, a comprehensive study investigating ultrasound's impact on seed water uptake dynamics, gene expression linked to seed hydration, and its association with germination rates has not yet been conducted.

The present study tested the contribution of ultrasound technology in enhancing seed hydration of three crop species with high economic value: pepper, maize and bean, its impact on germination and in the expression of genes involved in the germination process. Moreover, scanning electron microscopy and numerical simulation were utilized to evaluate the structural changes in seed coat in response to ultrasound. The study employed a variety of models to analyse hydration kinetics and found that ultrasound treatment consistently improved water uptake in all three studied species. Specifically, seeds exposed to ultrasound showed faster and higher water absorption rates, enhanced seedling growth, and significant modulation of gene expression. The treatment led to overexpression of aquaporin-coding genes and repression of genes involved in the abscisic acid (ABA) biosynthesis.

Overall, ultrasound treatment proved to be an effective priming strategy, enhancing seed hydration kinetics, modulating the expression of genes involved in water transport and ABA biosynthesis, and promoting germination and seedling growth, particularly in bean seeds. These findings highlight the potential of ultrasound technology as a sustainable tool to improve seed performance and bring valuable knowledge to the field of seed physiology and agricultural technology. © 2025 Society of Chemical Industry.