Effect of ethanol, putresciene and acetic acid on cadmium accumulation and toxicity in Indian mustard.

• All three agents significantly improved stress tolerability in mustard plants. • Heavy metal attenuating capacity of ethanol and acetic acid depicted. • Putresciene pretreatment showed best tolerance closely followed by acetic acid. Rapid increase in the accumulation of Cd in plants interrupt with metabolism thus inhibiting the growth and development. Hence, finding a remedy for Cd detoxification and improvement of plant's tolerability to metal toxicity is crucial. In this report, we investigate the differential responses to putrescine (PU), ethanol (ET) and acetic acid (AA) on Cd toxicity in conditions of metal aggregation and stress permissiveness in Indian mustard (Brassica juncea L.). Brassica juncea seedlings (12 day-old) were dealt with Cd (0.5 mM CdCl 2) alone and in combinations of PU (0.5 mM), 0.3% and 0.6% of ET and AA (250 µM) in hydroponic culture for three days. The enhancement in Cd concentration in the plant system induced reduction in growth, biomass and chlorophyll content due to heightened oxidative damage (raised malondialdehyde, MDA content; hydrogen peroxide, H 2 O 2 level) and gradual decrease in antioxidant defense. Cd treatment along with application of PU, ET and AA enhances growth of the plants as quantitated by biomass; represses oxidative damage; increases ascorbate-glutathione (AsA-GSH) and the activities of antioxidant enzymes (superoxide dismutase, SOD; glutathione reductase, GR; glutathione-S-transferase, GST; catalase, CAT; guaciol peroxidase, POX; glutathione peroxidase, GPx; polyphenol peroxidase, PPO; ascorbate peroxidase, APx; monodehydroascorbate reducatase, MDHAR and dehydroascorbate reductase, DHAR. Results indicated that PU, ET and AA plays a vital role in mustard seedlings by mitigating Cd toxicity and increasing the stress tolerance, through upregulating the antioxidant defense systems. Amelioration of heavy metal stress by ET and AA is being reported for the first time in this report. Although PU has been found to be the best among the three the ameliorating capacity of PU and AA are almost similar. [ABSTRACT FROM AUTHOR]