FIGHTING AGAINST PLANT SALINE STRESS: DEVELOPMENT OF A NOVEL BIOACTIVE COMPOSITE BASED ON BENTONITE AND L-PROLINE

MERINO DANILA; IGLESIAS MJ; MANSILLA Y; CASALONGUÉ C; ALVAREZ V

CLAYS AND CLAY MINERALS

CLAY MINERALS SOC

Año: 2021

0009-8604

Soil salinity constitutes one of the most critical environmental stresses affecting crop productivity, which must be urgently increased to meet the growing global demand for food. This unprecedented challenge requires actions that go beyond traditional practices. The use of nanotechnology in the agricultural field is rising today after the success of drug delivery nanosystems in health and pharmacology. In this context, this work deals with developing a new nanocomposite that tends to increase plants´ tolerance to saline stress by combining a natural bentonitenanoclay (Bent) with a phytoactive and osmoprotective compound, the amino acid L-Proline (Pro).The Bent-Pro nanocomposite synthesis method, its final chemical structure, andits in vitro bioactivity were fully addressed.Results indicate that Bent can retain a maximum of 14.4% (w/w) of Pro. The (001) diffraction peak of Bent shifted to lower angles in the X-ray diffraction pattern of Bent-Pro, indicating that Pro has a monolayer arrangement between Bent layers. The results of transmission electron microscopy additionally supported this result. Moreover, it has been found that Pro is also retained on the edges or external surface of Bent, as indicated by thermogravimetric analysis and scanning electron microscopy. Besides, Pro functional groups identified by Fourier Transform Infrared Spectroscopy indicated that it is present in its zwitterionic form. The role of Bent-Pro as plant saline stress protector was assayed on the plant model, Arabidopsis thaliana (A. thaliana), demonstrating that it mitigates the detrimental effects of NaCl-mediated salt stress on seed germination and the leaf chlorophyll level, thus highlighting the relevance of this contribution and the versatility and broad applicability of clays.