Responses of wheat and barley to Acacia saligna leaf and stem extracts: influence on growth and ascorbate-glutathione cycle

Abstract

The present study aimed to study the effect of dry leaf and stem leachates of Acacia saligna on wheat’s growth and enzyme functioning (Triticum aestivum) and barley (Hordeum vulgare). Leaf leachates (LL) and stem leachates (SL) of A. saligna were applied through root and nutrient solution in different concentrations i.e., 5, 10, and 15%. Treatment of LL and SL declined the growth in terms of height and dry weight in both tested plants in concentration-dependent manner with the maximal decline due to 15% LL. In addition, content of relative water, total chlorophylls, and carotenoids decreased in both wheat as well as barley. The activity of ascorbate peroxidase, monodehydro ascorbate reductase, dehydroascorbate reductase, and glutathione reductase increased considerably due to the treatment of LL and SL. The indigenous tolerance mechanisms in wheat and barley seedlings were further strengthened in wheat and barley by increased accumulation of glycine betaine, glutathione, and ascorbate in response to LL and SL treatment. Additionally, the activity of lipoxygenase and protease were increased significantly due to LL and SL treatment with a maximal increase at higher concentrations. From the present study it can be concluded that extracts of leaf and stem of A. saligna inhibit the growth of wheat and barley significantly with a concomitant increase in the functioning of the ascorbate-glutathione (AsA-GSH) cycle. Further, both crop species showed comparable responses to A. saligna leachates.