Effect of 28-homobrassinolide on the drought stress-induced changes in photosynthesis and antioxidant system of Brassica juncea L.

Abstract

To investigate the effect of exogenously applied 28-homobrassinolide (HBL) on drought-stressed plants, photosynthesis and antioxidant systems were examined in Indian mustard (Brassica juncea L.). Seedlings of Indian mustard were subjected to drought stress for 7 days at the 8-14 (DS1)/15-21 (DS2) days' stage of growth and then returned to normal conditions of growth. These seedlings were sprayed with HBL (0.01 lM) at the 30-day stage and were sampled at 60 days to assess the changes in growth, photosynthesis and antioxidant enzymes. Plants exposed to stress at either of the stages of growth exhibited a significant decrease in growth and photosynthesis. The exposure of plants to stress at an earlier stage (DS1) was more inhibitory than that at a later stage (DS2). However, the follow-up treatment with HBL significantly improved the values of these parameters and also overcame the inhibitory effect of water stress.

Establishment of sensitive and resistant variety of tomato on the basis of photosynthesis and antioxidative enzymes in the presence of cobalt applied as shotgun approach

“…cat, POs, sOD and that of proline content (table 13) in different cultivars of tomato in the present study is a biochemical adaptation of these cultivars to protect themselves against the oxidative stress that burst out in response to co stress. the literature of the recent years strongly favors this fact further as an increased in the antioxidant system was observed when the plants were exposed to co (chatterjee et al, 2006), nickel (alam et al, 2007), cadmium (hasan et al, 2008; hayat et al, 2009), aluminum (ali et al, 2008) and copper (Fariduddin et al, 2009). the present investigation reveals that co stress caused a significant reduction in the Nr activity of tomato cultivars.…”

Brassinosteroids improve photosystem II efficiency, gas exchange, antioxidant enzymes and growth of cowpea plants exposed to water deficit

“…With respect to water deficit in particular, BRs have been shown to mitigate the negative effects on gas exchange of Brassica juncea plants, increasing the photosynthetic rate, stomatal conductance and water-use efficiency (Fariduddin et al 2009). In addition, this substance also can reduce the oxidative damages due to increases in antioxidant enzyme activities in Lycopersicon esculentum plants (Yuan et al 2010).…”

Brassinosteroids Implicated in Growth and Stress Responses

“…These benefi cial effects resulted in higher leaf area, biomass production, grain yield, and yield-related parameters in the stress-treated plants. Results obtained by Fariduddin et al ( 2009a ) indicate that BRs may alleviate drought stress through activation of enzymatic antioxidant system such as CAT, APX, and SOD as well as stimulation of photosynthesis process in Brassica juncea plants. In drought-stressed Chorispora bungeana plants, BRs inhibited lipid peroxidation, measured in terms of malondialdehyde content, and stimulated antioxidant enzyme activity, chlorophyll content, and photosynthesis.…”