Phytoremediation potential of some halophytic species for soil salinity

Phytoremediation potential of six halophytic species i.e. Suaeda nudiflora, Suaeda fruticosa, Portulaca oleracea, Atriplex lentiformis, Parkinsonia aculeata and Xanthium strumarium was assessed under screen house conditions. Plants were raised at 8.0, 12.0, 16.0, and 20.0 dSm(-1) of chloride-dominated salinity. The control plants were irrigated with canal water. Sampling was done at vegetative stage (60-75 DAS). About 95 percent seed germination occurred up to 12 dSm(-1) and thereafter declined slightly. Mean plant height and dry weight plant(-1) were significantly decreased from 48.71 to 32.44 cm and from 1.73 to 0.61g plant(-1) respectively upon salinization. Na(+)/K(+) ratio (0.87 to 2.72), Na(+)/ Ca(2+) + Mg(2+) (0.48 to 1.54) and Cl(-)/SO4(2-) (0.94 to 5.04) ratio showed increasing trend. Salinity susceptibility index was found minimum in Suaeda fruticosa (0.72) and maximum in Parkinsonia aculeata (1.17). Total ionic content also declined and magnitude of decline varied from 8.51 to 18.91% at 8 dSm(-1) and 1.85 to 7.12% at 20 dSm(-1) of salinity. On the basis of phytoremediation potential Suaeda fruticosa (1170.02 mg plant(-1)), Atriplex lentiformis (777.87 mg plant(-1)) were the best salt hyperaccumulator plants whereas Xanthium strumarium (349.61 mg plant(-1)) and Parkinsonia aculeata (310.59 mg plant(-1)) were the least hyperaccumulator plants.

Acclimatory response to hydrogen peroxide and glutathione under salt-boron stress through their impact on mineral nutrition and antioxidant defense system in pigeonpea (Cajanus cajan L.)

Investigations were carried out on a salt tolerant (Manak, H77-216) and a comparatively salt sensitive (ICPL 88039) genotypes of pigeonpea (Cajanus cajan L. Millsp.) under NaCl, B and NaCl + B stress to examine the acclimatory response to H2O2, glutathione and H2O2 + glutathione through their effect on mineral nutrition, morpho-physiological parameters and antioxidant defense system. Both B and NaCl alone and their combinations had deleterious effect on dry biomass of plumule, enhanced relative stress injury (RSI), lipid peroxidation with concomitant increase in Na, Cl and B contents. However it did not bear any correlation with osmotic potential of plumule and K contents. Antioxidative enzymes like superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POX) and glutathione reductase (GR) also decreased with salt, B and salt + B treatments. However contents of H2O2 enhanced and that of ascorbate declined under aforementioned treatments. These injurious effects are partially alleviated by exogenous application of H2O2; glutathione (GSH) and H2O2 + GSH treatments. The role of H2O2 and GSH in the present study is suggestive of triggering multifunctional signal transduction in plant defense mechanisms to prevent cellular oxidation, membrane injury, lipid peroxidation and protein enzyme inactivation.