Chitosan nanoparticles as carrier systems for the plant growth hormone gibberellic acid

Abstract

This work concerns the development of nanocarriers composed of alginate/chitosan (ALG/CS) and chitosan/tripolyphosphate (CS/TPP) for the plant growth regulator gibberellic acid (GA). ALG/CS nanoparticles with and without GA presented mean size of 450±10nm, polydispersity index (PDI) of 0.3, zeta potential of -29±0.5mV, concentrations of 1.52×10 and 1.92×10 nanoparticles mL, respectively, and 100% encapsulation efficiency. CS/TPP nanoparticles with and without GA presented mean size of 195±1nm, PDI of 0.3, zeta potential of +27±3mV, concentrations of 1.92×10 and 3.54×10 nanoparticles mL, respectively, and 90% encapsulation efficiency. The nanoparticles were stable during 60days and the two systems differed in terms of the release mechanism, with the release depending on factors such as pH and temperature. Bioactivity assays using Phaseolus vulgaris showed that the ALG/CS-GA nanoparticles were most effective in increasing leaf area and the levels of chlorophylls and carotenoids. The systems developed showed good potential, providing greater stability and efficiency of this plant hormone in agricultural applications.

Evaluation of the effects of polymeric chitosan/tripolyphosphate and solid lipid nanoparticles on germination of Zea mays, Brassica rapa and Pisum sativum

“…Although not tested separately in the present study, it is known that the CS polymer is nontoxic and for this reason has considerable potential for applications in agriculture, where it can act as a biostimulant and/or reduce abiotic stress in plants, as well as increase resistance against pathogens (Pichyangkura and Chadchawan, 2015). According to this, in recent studies of our group, different CS-based nanoparticles have been shown to not impair germination and initial growth of Phaseolus vulgaris (Pereira et al, 2017a(Pereira et al, , 2017b. Regarding the acetic acid, the concentration present in the CS/TPP nanoparticles is 0.038 mM, and as described in literature the phytotoxic effects of acetic acid on seeds are observed in concentration higher than 4 mM (Tunes et al, 2012).…”

Effect of Some Nano Particle Materials on Leaf Area, Photo Synthetic Pigments and Minerals Content of Mango Trees

“…Zong et al (2016) in edible rape (Brassica rapa L.) found that, foliar application of chitosan promoted the plant growth and leaf chlorophyll contents. So, Pereira et al (2017) reported that, bioactivity assays using Phaseolus vulgaris showed that the alginate/chitosan (ALG/CS)-GA3 nanoparticles were most effective in increasing leaf area and the levels of chlorophylls and carotenoids.…”

Chitosan-Based Agronanochemicals as a Sustainable Alternative in Crop Protection

“…Plant growth regulators, also known as plant hormones, such as gibberellins, auxins, abscisic acid, cytokinin and ethylene are chemical substances responsible for regulating plant growth and plant cell development. Chitosan-gibberellic acid nanoparticles exhibited a 37% and 82% increase of root development and leaf area in French bean, respectively, compared to the free hormone, gibberellic acid [38]. Apart from that, more lateral roots were formed upon supplementation of chitosan-γ-polyglutamic acid-gibberellic acid nanoparticles on French bean seedlings compared to the free hormone [39], hence highlighting the benefits of the nanoparticulate systems.…”

“…Upon treatment, the seedlings showed an increase of leaf area, chlorophyll and carotenoids amount. [38] Chitosan-thiamine nanoparticles, 27 kDa, 85%…”