Effects of varied magnesium and potassium nutrition on wheat grown under ambient and elevated atmospheric carbon dioxide conditions

Official URL: http://risc01.sabanciuniv.edu/record=b1606650 (Table of Contents)

Atmospheric carbon dioxide (CO₂) has been continuously increasing from 280 μmol mol-1 in 1800’s up to 395 μmol mol-1 as of today and projected to elevate to some point in between 530 and 970 μmol mol-1 by the end of the 21st century. This study aimed to understand how low magnesium (Mg) and potassium (K) supply affects plant growth and physiology in an elevating CO₂ environment using two major wheat species (Triticum aestivum cv. Adana 99 and Triticum durum cv. Sarıçanak 98) as model plants. As expected low Mg and K treatments resulted in retarded biomass production and occurrence of severe leaf deficiency symptoms. Photosynthesis rate was significantly induced by elevated CO₂ treatments, however this induction was hampered by low Mg and K supply. Elevation of CO₂ resulted in accumulation of carbohydrates in source leaves particularly in low-Mg and low-K plants. In plants grown with adequate Mg and K, shoot and root biomass, root length and volume were significantly increased with elevated CO₂. However, growth enhancement resulting from elevated CO₂ was less pronounced in low-Mg and low-K plants. Total antioxidant capacity, lipid peroxidation and membrane stability were altered by low Mg and K supply irrespective of the [CO₂] treatments. Due to the detrimental effects of low Mg and K supply on phloem export of carbohydrates, photosynthesis rate, root properties linked to nutrient uptake from soil, antioxidative system and membrane structure, nutritional status of plants with Mg and K has crucial importance to take advantage of an atmosphere with elevating CO₂ levels.