Physiological and biochemical attributes of bread wheat (Triticum aestivum L.) seedlings are influenced by foliar application of silicon and selenium under water deficit

In climate change scenario, drought is one of the serious environmental stress that limits agricultural productivity throughout the world. Silicon (Si) and selenium (Se) are known to effect physiological and biochemical processes under environmental stress. Therefore, this study was carried out to investigate the effects of Si and Se in alleviating the adversities of drought stress on physiological and biochemical processes in bread wheat seedlings. Treatments comprised of control (CK) (no drought stress nor Si and Se added), only drought [40% water holding capacity (WHC)], drought+Si (40% WHC with 40mM Si), drought+Se (40% WHC with 40mM Se), and drought+Si+Se (40% WHC+40mM Si+40mM Si). Plant material consisted of one bread wheat cultivar, Faislabad-2008. Data were collected for root shoot traits, physiological traits, and antioxidant enzymatic activities of shoot. Data analyses revealed that deficit irrigation inhibited the morphological attributes (root and shoot dry weight, root, and shoot length), water relation parameters, chlorophyll contents, net photosynthetic rate, transpiration rate, stomatal conductance, and CO2 concentration of wheat seedlings. On contrary, the foliage applied Si alone and in combination with Se under water deficit conditions stimulated plant growth and photosynthetic attributes, water relations, transpiration rate, and chlorophyll contents. In addition, an increase in antioxidants enzymatic activity was recorded under water deficit conditions, which was higher in wheat seedlings treated with combined application of Si and Se. Correlation analyses revealed strong association of antioxidant enzymatic activities with osmotic potential and turgor pressure. It is concluded from the study that foliage applied Si alone alleviates the negative impact of water deficit condition, while in combination with Se, both collectively found more effective in mitigating adverse effects of drought stress.