Ameliorating Effect of Silicon on Growth Vigor, Physiological and biochemical Traits of Salinized Canola Seedlings (Brassica napus L.)

Abstract

In the present study the ameliorating effects of Si nutrition supplied as 1 mmol L−1 sodium silicate were proved on the seedling growth of canola (Brassica napus L.) seedlings under salinity stress (i.e. 0, 30, 60, 90 and 120 mmol L−1sodium chloride). Salinity obviously disrupted cellular homeostasis, something was evident in the decreased percent of scavenging HO-free radical and Metal chelating %, and hence reduction in photosynthetic pigments contents (chl.a and carotenoids). Silicon nutrition, however, enabled canola cells to balance between the steady-state levels of different ROS through improving the detoxification of the excess ROS. This was prevalent in higher scavenging percent of HO- and metal chelating. In addition, Si maintained membranes integrity through improved levels of lipid peroxidation inhibition %. Si buffered oxidative stress through sustaining the enzymatic and non-enzymatic scavenging capacity of reactive oxygen species in salt-stressed plants. Enzymatic antioxidants such as (CAT, SOD, APX, and POS) activities as well as non-enzymatic antioxidants such as carotenoids contents phenolics contents increased at 120 mmol L−1 sodium chloride. Thus, silicon nutrition alleviated the deleterious effects of salinity on the growth of canola plants through increased reactive oxygen species scavenging capacity (enzymatically and non-enzymatically), maintaining the membrane integrity of seedling cells as evidenced by raising the reducing power contents, sustained higher levels of chlorophyll. Consequently, enhance seedlings growth observations.