Work

Silica-based nanoencapsulation of proline enhances plant heat stress tolerance via antioxidant and hormonal regulation

Year: 2026

Type: article

Abstract: Heat stress (HS) severely affects plant growth and productivity worldwide. The application of osmoprotectant compounds, such as proline, has been shown to mitigate these effects; however, excessive or uncontrolled proline uptake can lead to pleiotropic effects that compromise plant development. Encapsulation technology offers a promising alternative to achieve a gradual and controlled release of proline, improving its protective efficiency. In this work, proline (Pro) was encapsulated using silica (Si:Pro) and chitosan (Ch:Pro) matrices at different ratios by a spray-drying process, an industrially scalable technique with potential relevance for agricultural applications. The proper homogenization of the Si or Ch matrices with Pro enabled the formulation of suspensions with suitable rheological behavior for efficient atomization. This subsequently allowed effective drying and the obtention of free-flowing particles with high thermal stability compared with non-encapsulated proline, and satisfactory encapsulation efficiencies. These properties allowed the use of Si:Pro and Ch:Pro samples at the three formulated ratios for subsequent biological experiments. In Arabidopsis thaliana , free Pro treatment negatively affected root and rosette growth under non-stress conditions, whereas encapsulated Pro, particularly Si:Pro, mitigated these effects through controlled release. Under HS conditions, plants treated with Si:Pro showed markedly enhanced growth, with root length increasing by ~80%, rosette area by ~100%, and fresh weight by ~20% compared with HS-treated controls. Furthermore, Si:Pro treatment promoted a more balanced hormonal profile, characterized by a roughly twofold increase in salicylic acid (SA), a threefold increase in abscisic acid (ABA), and an approximate 50% reduction in indole-3-acetic acid (IAA) relative to HS-treated plants. Moreover, plants treated with Si:Pro + HS exhibited moderate expression of proline biosynthetic genes, increased ascorbate peroxidase (APX) and glutathione reductase (GR) activities, and decreased lipid peroxidation, collectively supporting an enhanced redox homeostasis. Therefore, silica-based encapsulation of proline provides a controlled delivery system that reduces toxicity, enhances thermotolerance, and maintains physiological and hormonal balance in Arabidopsis thaliana under HS. These findings support its potential as a sustainable and scalable strategy to improve plant resilience, while highlighting the need for further optimization and validation across crop systems and environmental conditions.

Source: Plant Nano Biology

DOI: 10.1016/j.plana.2026.100264

Authors: Vanessa A. Avendaño, Jimmy Sampedro-Guerrero, Aurelio Gómez-Cadenas, Carolina Clausell-Terol

Institutions: Universitat Jaume I, Instituto de Tecnología Cerámica

Language: English

Topic: Plant Stress Responses and Tolerance

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $2,380