Physiological Effects of Smoke-water and Karrikinolide on Wheat Seedlings Grown under Boron Stress

Abstract

Abstract: It is well-recognized that plant-derived smoke and karrikinolide (KAR1) are capable of promoting seed germination and seedling growth in many plants. In addition, recent findings have suggested that smoke and KAR1 can alleviate the deleterious effects of unfavorable environmental conditions on plant growth. In this study, we aimed to determine the effects of smoke-water and KAR1 on growth and physiological parameters in wheat (Triticum aestivum L.) seedlings subjected to boron (B) stress. To accomplish this goal, 7-day-old seedlings were grown in nutrient solutions containing 12 mM boric acid with or without the presence of smoke-water (0.4 and 1%) and KAR1 (0.1 µM) for 5 days. Hydrogen peroxide, malondialdehyde, proline, total phenolic contents, antioxidant enzyme activities, and B concentration were determined for each treatment group. The results of the present study show that smoke-water and KAR1 improve root growth and decrease B accumulation in wheat seedlings under B stress. Moreover, KAR1 and smoke-water (0.4%), albeit not significant, led to a slight reduction in B-triggered oxidative injury. Our findings also suggest that the increased activities of glutathione reductase, peroxidase, and superoxide dismutase in B-treated seedlings return almost to control levels in the presence of KAR1 and smoke-water (0.4%). In conclusion, this study provides evidence that smoke and KAR1 have the potential to be used in agriculture in order to reduce the negative effects of excess B on plant growth.