Salt-Induced Changes in Physio-Biochemical and Antioxidant Defense System in Mustard Genotypes

Salinity stress is a major factor limiting plant growth and productivity of many crops including oilseed.The present study investigated the identification of salt tolerant mustard genotypes and better understanding the mechanism of salinity tolerance.Salt stresses significantly reduced relative water content(RWC),chlorophyll(Chl)content,K^(+) and K^(+)/Na^(+) ratio,photosynthetic rate(P N),tran-spiration rate(Tr),stomatal conductance(gs),intercellular CO_(2) concentration(Ci)and increased the levels of proline(Pro)and lipid peroxidation(MDA)contents,Na+,superoxide(O_(2)^(•−))and hydrogen peroxide(H_(2)O_(2))in both tolerant and sensitive mustard genotypes.The tolerant genotypes maintained higher Pro and lower MDA content than the salt sensitive genotypes under stress condition.The activities of superoxide dismutase(SOD),catalase(CAT),peroxidase(POD),glutathione peroxidase(GPX),monodehydroascorbate reductase(MDHAR)and dehydroascorbate reductase(DHAR)were increased with increasing salinity in salt tolerant genotypes,BJ-1603,BARI Sarisha-11 and BARI Sarisha-16,but the activities were unchanged in salt sensitive genotype,BARI Sarisha-14.Besides,the increment of ascorbate peroxidase(APX)activity was higher in salt sensitive genotype as compared to tolerant ones.However,the activ-ities of glutathione reductase(GR)and glutathione S-transferase(GST)were increased sharply at stress conditions in tolerant genotypes as compared to sensi-tive genotype.Higher accumulation of Pro along with improved physiological and biochemical parameters as well as reduced oxidative damage by up-regulation of antioxidant defense system are the mechanisms of salt tolerance in selected mustard genotypes,BJ-1603 and BARI Sarisha-16.

Antidepressant,anxiolytic and anti-nociceptive activities of ethanol extract of Steudnera colocasiifolia K.Koch leaves in mice model

Objective:To estimate the antidepressant,anxiolytic and antinociceptive activities of ethanol extract of Steudnera colocasiifolia K.Koch(S.colocasiifolia)leaves.Methods:Swiss albino mice treated with 1%Tween solution,standard drugs and ethanol extract of S.colocasiifolia,respectively,were subjected to the neurological and antinociceptive investigations.The tail suspension test and forced swimming test were used for testing antidepressant activity,where the parameter is the measurement of immobility time.Anxiolytic activity was evaluated by hole board model.Anti-nociceptive potential of the extract was also screened for centrally acting analgesic activity by using formalin induced licking response model and acetic acid induced writhing test was used for testing peripheral analgesic action.Results:Ethanol extract of S.colocasiifolia significantly decreased the period of immobility in both tested models(tail suspension and forced swimming models)of antidepressant activity.In the hole board model,there was a dose dependant(at 100 and 200 mg/kg)and a significant increase in the number of head dipping by comparing with control(1%Tween solution)(P<0.05 and P<0.001).In formalin induced licking model,a significant inhibition of pain compared to standard diclofenac sodium was observed(P<0.05 and P<0.001).In acetic acid induced test,there was a significant reduction of writhing response and pain in mice treated with leaves extract of S.colocasiifolia at 200 mg/kg body weight(P<0.05 and P<0.001).Conclusions:The results proofed the prospective antidepressant,anxiolytic and antinociceptive activities of ethanol extract of S.colocasiifolia leaves.