Effects of chitosan nanoparticles on seed germination and seedling growth of wheat (Triticum aestivum L.)

Resumo

Para investigar o efeito e o mecanismo das nanopartículas de quitosana (CSNPs) na germinação e crescimento de mudas de trigo (Triticum aestivum L.), conduzimos uma pesquisa sistemática sobre o impacto de diferentes concentrações (1-100 μg/mL) de CSNPs e quitosana ( SC). O resultado da espectroscopia de dispersão de energia (EDS) e microscopia confocal de varredura a laser (CLSM) mostrou que a adsorção de CSNPs na superfície de sementes de trigo foi maior do que a de CS. CSNPs tiveram efeito promotor de crescimento em uma concentração menor (5 μg/mL) em comparação com CS (50 μg/mL). Além disso, a aplicação de 5 μg/mL de CSNPs induziu a expressão gênica relacionada à auxina, acelerou a biossíntese e o transporte do ácido indol-3-acético (IAA) e reduziu a atividade da IAA oxidase, resultando no aumento da concentração de IAA na parte aérea e raízes do trigo.

Abstract

To investigate the effect and mechanism of chitosan nanoparticles (CSNPs) on the germination and seedling growth of wheat (Triticum aestivum L.), we conducted systematic research on the impact of different concentrations (1–100 μg/mL) of CSNPs and chitosan (CS). The result of energy-dispersive spectroscopy (EDS) and confocal laser scanning microscopy (CLSM) showed that adsorption of CSNPs on the surface of wheat seeds was higher than that of CS. CSNPs had growth promoting effect at a lower concentration (5 μg/mL) compared with CS (50 μg/mL). In addition, the application of 5 μg/mL CSNPs induced the auxin-related gene expression, accelerated indole-3-acetic acid (IAA) biosynthesis and transport, and reduced IAA oxidase activity resulting in the increase of IAA concentration in wheat shoots and roots. The results suggest that CSNPs have positive effect on seed germination and seedling growth of wheat at a lower concentration than CS due to higher adsorption on the surface of wheat seeds.