Iqbal Hussain

Acetyl and butyryl cholinesterase inhibitory sesquiterpene lactones from Amberboa ramosa

BackgroundAlzheimer’s disease (AD) is characterized by a progressive memory loss that leads to a profound emotional disturbance in later stages. As no safe and effective drug is yet available for the treatment of AD, secondary metabolites from plants may be instrumental in meeting this challenge. Keeping in view this point we evaluated sesquiterpenes of medicinal plant Amberboa ramosa for their cholinesterase inhibitory activity.ResultsFour sesquiterpene lactones have been isolated from the ethyl acetate soluble fraction of Amberboa ramosa. In which one compound Amberbin C (1) was found to be new while other three Amberin (2), Amberbin A (3), and Amberbin B (4) were previously reported ones. The structures of the isolated compounds were elucidated using different spectroscopic techniques. Isolated compounds were tested for their inhibitory potential against acetyl cholinesterase and butyryl cholinesterase enzymes. All compounds showed excellent inhibitory activities against acetyl cholinesterase and butyryl cholinesterase.ConclusionsA new sesquiterpene lactone has been isolated and fully characterized, the sesquiterpene lactones from Amberboa ramosa showed good inhibitory activities against acetyl cholinesterase and butyryl cholinesterase enzymes, this study indicated that sesquiterpene lactone can become interesting lead molecules in drug development against Alzheimer’s disease (AD).

Hydrogen peroxide modulates antioxidant system and nutrient relation in maize (Zea mays L.) under water-deficit conditions

A pot experiment was conducted to investigate the effect of presowing seed treatment with H2O2 (20, 40, 60, 80, 100, 120, and 140 mM) in maize grown under water-deficit conditions (moisture maintained at 100% and 60% field capacity). Higher germination rates were recorded when seeds were soaked in 140 mM of H2O2. A marked decline in photosynthetic pigments and increase in the concentration of proteins, H2O2, malondialdehyde (MDA), and ascorbic acid (AsA) were recorded in maize plants under water-deficit conditions. Drought stress caused a decline in potassium (K+) and calcium (Ca2+) contents while an increase in iron (Fe2+) and phosphorous (P) contents was recorded in maize plants. Activities of different antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) were also greatly enhanced in response to water-limited supply. Among different concentrations of H2O2 (20, 40, 60, 80, 100, 120, and 140 mM), seed treatment with 140 mM of H2O2 greatly reduced degradation of photosynthetic pigments, decreased MDA levels, and increased the concentration of AsA and activities of different antioxidant enzymes under water-deficit conditions. Hydrogen peroxide treatment stimulated the antioxidant system that resulted in the induction of drought tolerance of maize plants in terms of higher shoot and root fresh and dry masses.

Advances in microbe-assisted reclamation of heavy metal contaminated soils over the last decade: A review

Contamination of agricultural soils with trace metals present lethal consequences in terms of diverse ecological and environmental problems that entail entry of metal in food chain, soil deterioration, plant growth suppression, yield reduction and alteration in microbial community. Metal polluted soils have become a major concern for scientists around the globe. Phytoremediation involves the hyperaccumulation of metals in different plant parts. Phytoremediation of metals from polluted soils could be enhanced through inoculation with metal resistant plant growth promoting (PGP) bacteria. These PGP bacteria not only promote plant growth but also enhance metal uptake by plants. There are a number of reports in the literature where PGP bacterial inoculation improves metal accumulation in different plant parts without influencing plant growth. Therefore, there is a need to select PGP bacterial strains which possess the potential to improve plant growth as well as expedite the phytoremediation of metals. In this review, we have discussed the mechanisms possessed by PGP bacteria to promote plant growth and phytoremediation of metals. The central part of this review deals with the recent advances in microbial assisted-phytoremediation of metals.

Response of Maize Seedlings to Cadmium Application after Different Time Intervals

Present study was conducted to appraise the inhibitory effects of cadmium applied at different time intervals on various growth and biochemical parameters in two maize lines, Maize-TargetedMutagenesis 1 and 2 (MTM-1 and MTM-2). Twenty-day-old seedlings were exposed to 0, 3, 6, 9, and 12 mg CdCl2 kg−1 sand. Both maize lines exhibited significant perturbations in important biochemical attributes being employed for screening the crops for cadmium tolerance. The results showed that a higher concentration of cadmium (12 mg CdCl2 kg−1) considerably reduced the plant growth in line MTM-1 on the 5th, 10th, and 15th day after the treatment. In contrast, irrespective of exposure time, the plant biomass and leaf area did not show inhibitory effects of cadmium, specifically at 3 mg CdCl2 kg−1 in line MTM-2. In addition, MTM-2 was found to be more tolerant than line MTM-1 in terms of lower levels of hydrogen peroxide (H2O2), malondialdehyde (MDA) contents, and relative membrane permeability (RMP). Moreover, H2O2, MDA, RMP, and anthocyanin increased at all levels of cadmium in both lines, but a significant decline was observed in photosynthetic pigments, total free amino acids, and proline contents in all treatments particularly on the 10th and 15th day after treatment.

Mitigating the Effects of Salinity by Foliar Application of Salicylic Acid in Fenugreek

Present research work was conducted to alleviate the salinity-induced harmful effect on biomass production and physiochemical attributes of fenugreek by foliar application of salicylic acid. Two varieties (Deli Kabul and Kasuri) were grown in salt treated (100 mM NaCl) and untreated (0 mM NaCl) growth medium. Two levels of salicylic acid (0 mg L−1 and 100 mg L−1) were applied through foliar method. Salinity stress significantly reduced the growth biomass in both varieties. Higher shoot fresh weight was recorded in Deli Kabul, while lower in Kasuri. Such reduction in growth biomass was mitigated by the foliar application of SA in both plants. Salinity caused a marked reduction in gas exchange attributes including net CO2 assimilation rate, transpiration rate, stomatal conductance, and substomatal CO2 concentration. Exogenous applied salicylic acid also overcomes the reduction in gas exchange attributes of the plants. The varieties “Deli Kabul” and “Kasuri” showed higher and lower net CO2 assimilation rate, respectively. These results indicate that growth medium salinity induced reduction in biomass production, gas exchange attributes, and also chlorophyll contents whereas the application of SA through foliar method can be used to protect plant growth and improve these attributes under salt stress.

Effect of Salt Stress on Different Growth and Biochemical Attributes in Two Canola (Brassica napus L.) Cultivars

A pot experiment was conducted to appraise the differences in salinity tolerance in two canola cultivars (Shiralec and Dunkeld). The experiment was laid out in completely randomized design with five replications. Four salinity levels [0, 120, 150, and 180 mM sodium chloride (NaCl)] were used in this study. Salt stress caused a marked decrease in plant fresh and dry masses, photosynthetic pigments, and anthocyanins and increase in malondialdehyde (MDA), hydrogen peroxide (H2O2), and leaf phenolics. We have observed that salt tolerance ability of cv. Shiralec is greater than that of Dunkeld in terms of lower salt-induced decline in fresh and dry masses, photosynthetic pigments, lower MDA, H2O2 contents, and greater leaf phenolics.

Exogenous proline and glycinebetaine mitigate cadmium stress in two genetically different spring wheat (Triticum aestivum L.) cultivars

A pot experiment (completely randomized design with four replications) was conducted to appraise the role of exogenously applied proline and glycinebetaine in ameliorating the inhibitory effects of cadmium (Cd) in two wheat cultivars, namely Millat-2011 and Punjab-2011. The Cd stress caused a marked decrease in shoot fresh and dry masses, leaf chlorophylls, carotenoids, anthocyanins, and phenolic contents while increase in tissue malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents. Foliar spray of proline and glycinebetaine caused a significant change in growth and physiochemical attributes of two wheat cultivars under Cd stress. Although both proline and glycinebetaine were effective, plants treated with proline had markedly greater shoot and root fresh masses, leaf phenolics, lesser degradation of chlorophylls, and accumulation of MDA and H2O2 contents under Cd stress. Of the two wheat cultivars, Millat-2011 exhibited better tolerance to Cd toxicity in terms of greater leaf phenolics, lesser damage to photosynthetic pigments, and reduced accumulation of MDA and H2O2 contents.

Corniculatin A, a new flavonoidal glucoside from Oxalis corniculata

Oxalis corniculata L. (creeping wood sorrel) is medicinally important member of family Oxalidaceae, and is distributed in the tropical and subtropical regions of the world. It has been used in different systems of traditional medications for different diseases. Corniculatin A, a new flavonoid glucoside, was isolated from the ethyl acetate soluble fraction of the whole plant along with luteolin, luteolin-7-O-β-D-glucoside and β-sitosterol-3-O-β-D-glucoside, This is the first report of these compounds from this species. Their structures were elucidated on the basis of spectral data including mass and 2D NMR experiments.

Phenological application of selenium differentially improves growth, oxidative defense and ion homeostasis in maize under salinity stress

The underlying mechanism of selenium (Se) mediating plant salt tolerance is not well understood and information on how plant growth and development is regulated by phenological Se application (20 and 40 mg/L) under salinity stress is scarce. In present study, we have appraised the impact of phenological Se application on growth, antioxidant defense system and ionic imbalance in maize under salinity. Salinity (12 dS m-1) reduced growth, concentration of chlorophyll and K+ in root and leaf. Contrarily, salinity increased toxic Na+, malondialdehyde (MDA) and H2O2 concentration that resulted in oxidative damage. Lower level of Se application (20 mg/L) increased growth and chlorophyll by reducing oxidative damage due to high cell concentrations of MDA and H2O2. Se reduced endogenous levels of H2O2 and MDA under salinity. Moreover, Se regulated antioxidant defense system by increasing the activities of antioxidant enzymes (SOD, POD and CAT) and influenced the concentrations of non-enzymatic antioxidants (phenolics and flavonoids). Se-induced better antioxidant system protected plants from oxidative damage. We have also recorded substantial increase in K+ and decrease in Na+ concentration in plants treated with 20 mg/L Se under salinity stress. The impact of Se on plant growth and development is linked with the growth stage of exogenous application. Foliar Se at reproductive and both vegetative and reproductive stages improved salinity tolerance in maize compared with vegetative stage.

Glycine betaine counteracts the inhibitory effects of waterlogging on growth, photosynthetic pigments, oxidative defence system, nutrient composition, and fruit quality in tomato

ABSTRACT Glycine betaine (GB) is an important organic compound mediating plant responses to environmental stresses. However, despite ample research on this biomolecule, the potential of GB in mitigating the effects of waterlogging in plants has not been established. Therefore, we studied the influence of GB on growth and physiology of tomato plants under waterlogged conditions. Waterlogging reduced plant growth, degraded chlorophyll, and increased concentration of malondialdehyde and hydrogen peroxide that deteriorated membrane integrity. Waterlogging increased catalase and peroxidase activities. Waterlogging increased the concentration of Na and reduced concentrations of K. Reductions in root Ca were also recorded. GB enhanced growth, concentration of chlorophyll and activities of superoxide dismutase, catalase, and peroxidase that in turn protected the plants from oxidative damage. GB decreased Na while increasing leaf and root K and stem and fruit Ca under waterlogging. Waterlogging reduced fruit quality. There was decrease in protein, fat, and total dissolved solids and an increase in fruit moisture, P, and Na in plants under waterlogging. GB enhanced fruit quality largely by improving fruit protein, ash, fat, TDS, and Ca, while it decreased fruit Na. The results of this study suggest the use of GB for commercial production of tomato where waterlogging is likely.