Encapsulation Reduces the Deleterious Effects of Salicylic Acid Treatments on Root Growth and Gravitropic Response

Abstract

The role of salicylic acid (SA) on plant responses to biotic and abiotic stresses is well documented. However, the mechanism by which exogenous SA protects plants and its interactions with other phytohormones remains elusive. SA effect, both free and encapsulated (using silica and chitosan capsules), on Arabidopsis thaliana development was studied. The effect of SA on roots and rosettes was analysed, determining plant morphological characteristics and hormone endogenous levels. Free SA treatment affected length, growth rate, gravitropic response of roots and rosette size in a dose-dependent manner. This damage was due to the increase of root endogenous SA concentration that led to a reduction in auxin levels. The encapsulation process reduced the deleterious effects of free SA on root and rosette growth and in the gravitropic response. Encapsulation allowed for a controlled release of the SA, reducing the amount of hormone available and the uptake by the plant, mitigating the deleterious effects of the free SA treatment. Although both capsules are suitable as SA carrier matrices, slightly better results were found with chitosan. Encapsulation appears as an attractive technology to deliver phytohormones when crops are cultivated under adverse conditions. Moreover, it can be a good tool to perform basic experiments on phytohormone interactions.

Protective effects of chitosan based salicylic acid nanocomposite (CS-SA NCs) in grape (Vitis vinifera cv. ‘Sultana’) under salinity stress

“…Considering that SA and CS have shown effective effects on plant growth, physiological, and biochemical parameters, especially anthocyanins and enzymes, the combination of nanoparticles (CS-SA NCs) may have a synergistic effect due to the effect of chitosan 22 CS-SA treatments with the lowest encapsulated ratio reduced the toxicity of free SA on Arabidopsis thaliana. In this system, plants treated with capsule, CS-SA had more root and rosette growth than plants treated with free SA 23 .…”

Carrier‐based delivery system of phytohormones in plants: stepping outside of the ordinary

“…This process includes a bioactive compound that is the core material encapsulated within the carrier matrix. The carrier matrix must possess properties like flexibility to effectively encapsulate bioactive compounds (Sampedro-Guerrero et al, 2022). Biopolymers are natural components derived from natural sources by chemical or biological methods; for example, sodium alginate, chitosan and cellulose (Díez-Pascual, 2022).…”

“…The ability to accurately control endogenous hormone levels through PGR encapsulation allows for a targeted response to stress in various plant tissues and organs (Liu et al, 2024). Moreover, the regulated release of different agricultural products and improved bioavailability have been made possible by the encapsulation of phytohormones (Sampedro-Guerrero et al, 2023). This approach creates new opportunities to improve plant stress tolerance, which is crucial for contemporary farming.…”

“…Encapsulation of active molecules can be an effective method to reduce/or manage the various stresses in plants through enhancement of the plant immunity; for example, encapsulated salicylic acid provides resistant against Fusarium verticillioides and Sclerotium rolfsii in maize and rice (Kumaraswamy et al, 2019;Panichikkal et al, 2021). Further, encapsulation releases particles with high hydrophilicity and lipophilicity, which enhances their ability to penetrate plant tissues and activate plant antioxidant mechanisms (Marques Mandaji et al, 2022;Sampedro-Guerrero et al, 2023). The very interesting thing is that the encapsulation of biological control agents shows targeted-specific activity and slow delivery (Campos et al, 2014).…”

Efficient strategies for controlled release of nanoencapsulated phytohormones to improve plant stress tolerance

“…SA controls several aspects of plant development, including seed germination, root differentiation and growth, photosynthesis, stomatal closure, senescence, flowering, and fruit yield [ 16 ]. Interestingly, SA enhances plant antioxidant capacity at low concentrations but causes pleiotropic effects and susceptibility to abiotic stresses at highest ones [ 17 , 18 ]. It plays a key role in inducing the systemic acquired resistance to various pathogens and, in coordination with ABA, regulates plant defense responses against pathogens and pests [ 19 ].…”