| Abstract: | Drought is the most common form of abiotic stress that reduces plant growth and productivity. It causes plantinjuries through elevated production of reactive oxygen species (ROS). Potassium (K) is a vital plant nutrient thatnotably ameliorates the detrimental effect of drought stress in the plant. A pot experiment was conducted at theLaboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Japan, under controlled environment of green house to explore the role of K in mitigating drought severity in wheat (Triticum asevitum L.)seedlings. Three days after germination, seedlings were exposed to three water regimes viz., 100, 50, and 20% fieldcapacity (FC) for 21 days. Potassium was adjusted in Hoagland nutrient solution at 0, 6 and 12 mM concentrationand applied to pot instead of normal water. Results show that, water deficit stress notably reduced plant growth,biomass accumulation, leaf relative water content (RWC) along with reduced photosynthetic pigments. Increasedamount of biochemical stress markers viz., malondialdehyde (MDA), hydrogen peroxide (H2O2), methylglyoxal(MG), proline (Pro) as well as an impaired antioxidant defense system were observed in drought affected wheatplants. On the contrary, K supplementation resulted in improvement of biochemical and physiological parametersthat worked behind in improving growth and development of the wheat plants. In addition, enzymes of ascorbateglutathione (AsA-GSH) cycle were also enhanced by supplemented K that accelerated the ROS detoxification process in plant. Although glyoxalse system did not performed well till MG was detoxified might following anothershort stepped pathways. Our results revealed that drought stressed plants showed better performances in terms ofbiochemical and physiological attributes, antioxidant defense and glyoxalase system, as well as ROS detoxificationdue to K supplementation with better performance at 12 mM K added in 50% FC growing condition. |
