Amelioration of salt stress effects on the morpho-physiological, biochemical and K/Na ratio of <i>Vicia faba</i> plants by foliar application of yeast extract

Abstract

Salinity is one of the most severe environmental stresses that negatively affects field crops' development and biochemical properties on a widespread global scale. Consequently, aiming to reduce the negative impact of salinity on plants, the objective of the current work was to study the effect of foliar spraying with two doses of yeast extract (2 and 4 g/L) on improving the growth of Vicia faba plants under NaCl stress (100 mM). The recorded results indicated that 100 mM NaCl level significantly decreased all investigated growth metrics (shoot height, root length, number of leaves, leaf area, fresh and dry weights of shoot and roots). Likewise, concentration of chloroplast pigments and the contents of total soluble protein and sugars were reduced in salt stressed faba bean leaves. Nevertheless, data revealed that V. faba plants grown under NaCl stress and sprayed with yeast extract had better growth behavior than those unsprayed. It was found that yeast extract treatment had the ability to induce significant recovery for the reduction occurred in vegetative growth of V. faba plants which exposed to salinity stress by more enhancement of pigment, total soluble protein and sugars contents. Among the yeast extract doses, 2 g/L significantly improved plant growth, biochemical traits and exposed high Mg, K, P content and K/Na ratio in V. faba plants grown under saline stress. It was found that treating V. faba plants with yeast extract can significantly restore the loss of vegetative growth caused by salt stress.