Evaluation of chitooligosaccharide application on mineralaccumulation and plant growth in Phaseolus vulgaris

Abstract

tChitooligosaccharides (COS) – water soluble derivatives from chitin, are an interesting group of moleculesfor several biological applications, for they can enter plant cells and bind negatively charged molecules.Several studies reported an enhanced plant growth and higher crop yield due to chitosan application insoil grown plants, but no studies have looked on the effect of COS application on plant mineral nutrientdynamics in hydroponically grown plants. In this study, Phaseolus vulgaris was grown in hydroponicculture and the effect of three different concentrations of COS on plant growth and mineral accumulationwas assessed. There were significant changes in mineral allocations for Mo, B, Zn, P, Pb, Cd, Mn, Fe, Mg,Ca, Cu, Na, Al and K among treatments. Plant morphology was severely affected in high doses of COS,as well as lignin concentration in the stem and the leaves, but not in the roots. Chlorophyll A, B andcarotenoid concentrations did not change significantly among treatments, suggesting that even at higherconcentrations, COS application did not affect photosynthetic pigment accumulation. Plants grown athigh COS levels had shorter shoots and roots, suggesting that COS can be phytotoxic to the plant. Thepresent study is the first detailed report on the effect of COS application on mineral nutrition in plants,and opens the door for future studies that aim at utilizing COS in biofortification or phytoremediationprograms.