Development and assessment of alginate microparticles for the controlled release of bioactive compounds to plants

• Autor(a) principal: Magalhães, Pedro António Ribeiro
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/39780
• topic: Alginate; Biopolymers; Controled-delivery systems; Drougth stress; Microstructures; Peptides; Photosynthesis; Metabolomic; Stress tolerance

Taking advantage of the biodegradability, marginal-toxicity, and the ability to form hydrogels, alginate (ALG) can be used to the controlled-delivery of active substances to plants. Since biopolymers as well as other biostimulants can promote growth and mitigate drought stress in plants, the combination can be synergetic in plants. Thus, the main objective of this work was to develop alginate microstructures and evaluate their effect in plant model species. Firstly, was study how synthesis parameters can affect alginate hydrogel structure. After obtaining alginate microparticles (CAG), was evaluated is effect in the germination and development of tomato (Solanum lycopersicum L.) and wheat (Triticum aestivum L.) seeds. Finally, evaluated the effect of CAG without or with the incorporation of PpT-2 peptide (CAG@PpT-2), in morphology, physiology and metabolic profile of tomato plants (Solanum lycopersicum L. cv Micro-Tom) grown under optimal conditions and under water stress conditions. In general, drying method was the one that most affected ALG hydrogels morphology and swelling capacity. When applied during germination, CAG promoted the germination and development of seeds. In tomato plants, CAG positively affected leaf morphology, photosynthetic process, phytohormone accumulation, and altered the metabolic profile. In stressed plants, the same beneficial effect was observed. PpT-2 alone had a beneficial effect on non-photochemical phase of photosynthesis and promoted the accumulation of phytohormones. The conjugation, CAG@PpT-2, did not potentiate the effect of each but maintained a beneficial effect on leaf morphology and in the non-photochemical phase of photosynthesis.