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Essential nutritional components are quantified in the study in addition to major antioxidants, carotenoids, phenols and flavonoids. Their antioxidant activities were also analyzed using DPPH, ABTS and hydrogen peroxide radical scavenging activities and by determining their iron reducing power. Results indicated that the highest quantity of nutritional and antioxidant components was obtained in red variety (4.63 mg/g ascorbic acid, 10.32 mg/g total carotenoid content, 61.50 mg/g total flavonoid content, 310.27 mg/g total phenolic content) followed by orange, yellow and green varieties. Similar trend was observed while analyzing their antioxidant activities by different methods. In studying correlation between components and antioxidant activity, a strong correlation was obtained for ABTS radical scavenging activity with total phenolic content (R2 = 0.722) and total carotenoid contents (R2 = 0.709), while moderate correlation was observed for ABTS radical scavenging activity with total flavonoid contents (R2 = 0.517) and ascorbic acid (R2 = 0.673).
The present study was conducted to evaluate the effect of NaCl on growth and some key antioxidants in chickpea. Eight genotypes of chickpea were grown hydroponically for 15 days and then treated with different concentrations of salt [0 mM (T0), 25 mM (T1), 50 mM (T2), 75 mM (T3), and 100 mM (T4)]. Salinity showed marked changes in growth parameters (fresh and dry weight of root and shoot). The level of lipid peroxidation was measured by estimating malondialdehyde content. Lipid peroxidation increases with the increase in NaCl concentration in all genotypes but salt-tolerant genotypes (SKUA-06 and SKUA-07) were least affected as compared to other genotypes. The chlorophyll content was also affected with elevated levels of NaCl. Increased concentration of salt increased the activity of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase in all chickpea genotypes but maximum activity was observed in salt-tolerant (SKUA-06 and SKUA-07) genotypes. Two genotypes of salt-tolerant and salt-sensitive varieties were analyzed further by real time PCR which revealed that the expression of SOD, APX and CAT genes were increased by NaCl in the salt-tolerant variety. The enhancement in tolerance against salt stress indicates that the genes involved in the antioxidative process are triggered by oxidative stress induced by environmental change. The results indicate that NaCl-induced oxidative stress hampers the normal functioning of the cell. The efficient antioxidants play a great role in mitigating the effect of NaCl stress in chickpea. This screening of NaCl-tolerant genotypes of chickpea can be performed on salt-affected land.
Enhanced yield of tomato has ever been an important issue due to its nutritional value and various dietary consumption forms. But, efficient yield increase can never be achieved without using environmentally safe means e.g. innate resistance. In present study, tomato innate antifungal resistance has been boosted up using Penicillium oxalicum, and then various aspects of resistance modulation have been explored in details. Two tomato varieties of differential antifungal resistance (Dinaar and Red Tara) were treated with six P. oxalicum strains which screened the best inducer strain (Pn 5); which remarkably controlled disease incidence (DI) of Alternaria alternata. Inducer was not only responsible for almost two times production of phenolics, alkaloids and terpenoids in Red Tara, but it also non-significantly triggered same biochemicals in Dinaar. Hemicellulose showed only 40 % increase in variety of least antifungal resistance. During quantification assays of peroxidase (POD), phenyl ammonia lyase and polyphenol oxidase, more or less the same doubling trend was recorded in susceptible variety, while only POD had significant enhancement in resistant variety under the influence of fungal inducer. It was also recorded that inducer not only modulated quantity of enzyme (glucanase), but its isozyme package was also altered. Colorimetric quantifications of lignin, cellulose and pectins proved that biotic inducer strengthened the physical structure of plant cells by increasing these contents from 30 to 120 %. The above investigation collectively comes with the recommendation of an efficient and environmentally safe inducer (P. oxalicum); which, can be used to control fungal pathogens.
The present study reports a high frequency in vitro propagation protocol through apical bud sprouting and basal organogenic nodule formation in shoot tip explants of Decalepis hamiltonii, an endemic and endangered medicinal liana. Among different combinations of plant growth regulators (PGRs) and growth additives, maximum of 8.20 shoots per explant with mean shoot length of 6.54 cm were induced on Murashige and Skoog’s medium (MS) supplemented with 5.0 µM 6-benzyladenine (BA) + 0.5 µM indole-3-acetic acid (IAA) + 30.0 µM adenine sulphate (ADS) through apical bud sprouting. On single cytokinin treatment explants did not exhibit good multiplication but showed nodulation (N₁) from the basal cut end similar to cytokinin–auxin combination (N₂). Between two types of nodular tissues, N₂ was proved to be better for maximum shoot regeneration (15.40 shoots per explant) and shoot length (4.56 cm) when cultured on MS medium supplemented with 5.0 µM BA, 0.5 µM IAA, 30.0 µM ADS and 1.0 µM gibberellic acid (GA₃). Microshoots were efficiently rooted on half-strength MS medium supplemented with 2.5 µM α-naphthalene acetic acid (NAA). After successful acclimatization in Soilrite, 95.10 % plantlets were survived in field conditions. Histological investigation proved useful in ascertaining the callogenic nature of the regenerating nodular tissue formed at the basal cut end of shoot tip explant. Acclimatized plantlets were studied for the estimation of chlorophyll and carotenoid content as well as the net photosynthetic rate (PN) during subsequent days of transfer to ex vitro condition. Moreover, acclimatization had a significant effect on biomass production and the synthesis of 2-hydroxy-4-methoxy benzaldehyde (2HMB). Maximum fresh weight (3.78 gm/plant), dry weight (0.39 gm/plant) of roots and 2HMB content (15.94 µg/ml of extract) were noticed after 8 weeks of acclimatization.
The plants of mung bean (Vigna radiata L. Wilczek) were raised from the seeds soaked in water (control), IAA or 4-C-IAA (10⁻⁶, 10⁻⁸ or 10⁻¹⁰ M) for 8 or 12 h. The plants were allowed to grow in a net house and were sampled at 30 and 45 days after sowing (DAS). Both IAA and 4-Cl-IAA significantly affected the growth (length, fresh and dry mass of roots and shoots), the number of nodules, their fresh and dry mass and the activity of nitrogenase. However, the contents of nitrogen and carbohydrate exhibited a decrease in response to both the auxins. 4-Cl-IAA, at a concentration of 10⁻⁸ M, generated the best response. Moreover, 4-Cl-IAA at other two concentrations (10⁻⁶ and 10⁻¹⁰ M) was much more active than any of the IAA concentration used.
Salt stress is among the major abiotic stresses that adversely affect the global crop production and its adverse impacts are getting more serious in the regions where saline water is used for irrigation. It induces reactive oxygen species, alters the activity of antioxidant system and adversely affects the process of photosynthesis. Various strategies have been employed to mitigate the deleterious effects of salt stress. Presently, the recommended strategies to overcome the adverse effects of salt stress include the use of tolerant cultivars, ameliorative water management and diverse cultural practices. However, none of these approaches have been found to be fully effective under salt stress conditions. An alternative and technically simpler approach to induce salt stress tolerance is the exogenous application of plant growth regulators (PGRs). This technique has gained significant importance during the past decade. PGRs have been implicated to regulate a wide range of metabolic and physiological activities in plants, ranging from cell division and organogenesis to protection against biotic and abiotic stresses. One of the important factors for enhanced plant productivity by PGRs is their efficiency to overcome the salt-induced stress conditions. Recent findings on the effects of brassinosteroids and polyamines on the salt stress tolerance of crops open new avenues to address the salinity problems. This review enlightens the role of brassinosteroids and polyamines in different plant processes like their role in regulation of photosynthesis, antioxidant systems and other related aspects, thereby improving overall performance of plants.
Phytoremediation of Cd, As, Cu, and Zn by Spirulina Platensis is one of the most cost-effective approaches and environmental friendly technologies used to remediate contaminants from contaminated water. The removal rates of Cd, As, Cu, and Zn in the field experiment were 14.95, 9.45, 35.55, and 73.95 μg/g/d, respectively. The highest concentrations of these metals accumulated in S. Platensis after 90 d of the laboratory/field collected samples were 58.9/98.68, 29.86/47.98, 43.28/235.86, and 249.67/390.65 μg/g dry wt., respectively, over the experiment. Only 55% Cd, 35% As, 85% Cu, and 95% of Zn removed from the water were used by S. Platensis. The bioconcentration factors were recorded for the metals in field/laboratory: for Cd (BCF=90/536), As (BCF=135/2,155), Cu (BCF=34,200/62,300) and Zn (BCF=32,500/95,300). The data obtained suggest that cyanobacterium S. Platensis has promising potential and can be used in a synergistic way to remediate wastewater polluted by Cd, As, Cu, and Zn.
Endoxifen, an active metabolite of tamoxifen, has been shown to be an effective anti-estrogenic agent in estrogen receptor-positive breast cancer patients. In melanoma, estrogen receptor expression is shown to be associated with disease progression. However, the therapeutic benefit of endoxifen in melanoma has not yet been evaluated. Here, we present the first demonstration of the anti-melanogenic activity of endoxifen in vitro and in vivo. The in vitro cytotoxic effect of endoxifen was tested using a cell viability assay. The in vivo anti-melanogenic activity was evaluated in B16F10 cell-bearing C57BL/6 mice, a mouse melanoma model. The general toxicity was tested in Swiss albino mice. Endoxifen exhibited greater activity against melanoma cell lines. Treatment of B16F10 mouse and SK-MEL-5 human melanoma cell lines with 10 μM of endoxifen for 48 h respectively resulted in 93.6 and 92.5% cell death. Orally administered endoxifen, at dose levels of 4 and 8 mg/kg body weight/day for 20 consecutive days, respectively reduced metastatic melanoma nodules in the lungs by 26.7 and 82.7%. Endoxifen was found to be a safe and effective anti-melanogenic agent in animal studies.
During our current study we evaluated the effect of ethylenediaminetetracetic acid (EDTA) and Enterobacter sp. CS2 on nickel stress alleviation and phytoextraction by Impatiens balsamina L in spiked soil. Nickel resistant Enterobacter sp. CS2 was isolated from soil polluted by industrial effluents. The I. balsamina seeds primed with Enterobacter sp. CS2 were raised in EDTA-supplemented soil (10 mM) contaminated with 0, 100, 200, and 300 mg kg⁻¹ Ni for 50 days. The effect of different treatments on plant growth attributes, nickel tolerance index, bioconcentration factor, and translocation factor were evaluated. The Ni stress reduced plant growth, carotenoids, and chlorophyll (chl) content. However, higher Ni uptake and proline contents were observed in plants growing in Ni-contaminated soils. The Enterobacter sp. CS2 inoculation further enhanced Ni uptake and proline contents in I. balsamina plants growing under Ni stress. The inoculated plants showed improved shoot length, root length, carotenoid content, chl ‘a’ and ‘b’ contents, root and shoot dry weight. The Ni tolerance index in Enterobacter sp. CS2-assisted plants was much higher compared to un-inoculated ones. The inoculated plants supplemented with EDTA enhanced 39%, 34%, and 30% Ni uptake in roots respectively under 100, 200, and 300 mg kg⁻¹ of Ni treatment as compared with un-inoculated plants. The data regarding bioconcentration factor and translocation factor showed that Ni phytoextraction capability of I. balsamina plants was significantly enhanced with the supplementation of Enterobacter sp. CS2 and EDTA.
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 µM) 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. The activity of antioxidant enzymes [catalase (E.C. 1.11.1.6), peroxidase (E.C. 1.11.1.7) and superoxide dismutase (E.C. 1.15.1.1)] and proline content in leaves exhibited an increase in response to both the treatment factors, where their interaction had an additive effect. It was, therefore, concluded that the elevated antioxidant system, at least in part, was responsible for amelioration of the drought stress.
Some rhizobacteria are capable of improving metal tolerance and growth of plants under heavy metal stress. The objective of the current study was isolation and subsequent application of cadmium-resistant rhizobacteria in phytoremediation by Catharanthus longifolius. The screened bacterial isolate exhibited growth-promoting attributes, including phosphate solubilization, ACCD activity, auxin, and siderophores production. The inoculation of Acinetobacter sp. CS9 under greenhouse trial improved growth and phytoextraction capability of C. longifolius plants in soils contaminated with different concentrations (0, 100, and 200 mg kg⁻¹) of Cd. The plants exhibited reduced quantity of total soluble protein, soluble sugars, and chlorophyll contents under Cd stress. On the other hand, improved chlorophyll, soluble protein, and sugar contents were observed in Acinetobacter sp. CS9-treated plants. The inoculated plants exhibited improved activity of antioxidant enzymes (SOD and CAT) and reduced malondialdehyde levels. Moreover, higher Cd uptake and translocation ratio was observed in Acinetobacter sp. CS9-inoculated plants as compared to un-inoculated ones. The current study showed that Acinetobacter sp. CS9 reduced Cd-induced oxidative stress and improved the phytoremediation capability of C. longifolius.
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