Physiological effects of stigmasterol on growth, productivity and certain metabolic activities of two economic crop plants grown under salinity stress

Abstract

The objective of the present work is to study the effect of various levels of salinity (0, 100, 150 and 200 mM NaCl) on growth, some related metabolic activities and productivity of flax (Sakha 2) and faba bean (Sakha 1). Also, the present investigation was focused on the effect of seed soaking in stigmasterol (200 ppm) to alleviate or at least modify the pattern of changes induced by the salinization treatment. The main experimental results can be briefly summarized in the following points: 1- The obtained results revealed that all growth criteria (shoot and root length, leaf area, number of leaves per plant, fresh and dry weights of both shoot and root system) were markedly reduced with increasing salinity levels, and the inhibitory effect of salt stress was much more pronounced at the highest level of salinity and in flax compared with faba bean plant at different stages of plant growth and development. Applications of stigmasterol by seed soaking led to a significant increase in the above growth characteristics of salt stressed flax and faba bean plants, as compared with those of the corresponding saline stressed plants. 2- Increasing the salinity levels caused marked decreases in the contents of IAA and GA3, and marked increases in the levels of ABA in both plants at vegetative stage. Application of stigmasterol resulted in marked and progressive increases in the IAA and GA3 levels and a decrease in ABA content in the two studied plants.