Layered double hydroxide as nanocarrier of Tryptophanfor the development of novel agro-inputs

MARIA FLORENCIA SALCEDO; ANA GARROTE; GIPSY PEÑA RAMIREZ; VERA ALVAREZ; LEONARDO CANO; ROMINA OLLIER; ANDREA YAMILA MANSILLA

Maceió

Encuentro; XXI Brazilian Materials Research Society Meeting (XXI B-MRS); 2023

The application of free amino acids has multiple functions as biostimulants of plant growthand development. Particularly, the use of Tryptophan (Trp) has positive effects on cropgrowth and productivity, as well as mitigating the negative effect abiotic stress [1].Nevertheless, tryptophan (Trp) is an aromatic chemical compound that is susceptible tophotooxidation and degradation upon exposure to UV light, which give it limitations when itcomes to ensuring its effectiveness on a productive scale [2]. Layered double hydroxides(LDH) belong to the class of anionic clays whose structure is based on layers similar tobrucite (Mg(OH) [3]. Our working hypothesis is based on the fact that LDH functionalizedwith Trp (LDH-Trp) have high potential as a novel active compound for applicationpurposes, since the functionalized nanoclays confer stability to the active principle. In thepresent work, an HDL of Mg-Al was synthesized by co-precipitation and subsequentlymodified by ion exchange to tailor it for use as a Trp nano-carrier. The developednanocarrier was characterized by Fourier-transform infrared spectroscopy (FTIR), whichdemonstrated the successful incorporation of Trp into the LDH matrix. Subsequently, therelease profiles of Trp were determined. The biological functionality of LDH-Trp was testedin a bioassay in Arabidopsis thaliana plant model system. The primary root growth ofArabidopsis seedlings is strongly inhibited by high concentrations of free Trp. Arabidopsisseedlings cultivated in LDH-Trp exhibited similar root growth than free Trp. Our findingssuggest a promising scenario for employing LDH as a nanocarrier of Trp in the developmentof novel agro-inputs.