Exogenous Application Of Ascorbic Acid Research Articles

Erratum to: Metabolic responses of tea (Camellia sp.) to exogenous application of ascorbic acid

Erratum to: Metabolic responses of tea (Camellia sp.) to exogenous application of ascorbic acid

Metabolic responses of tea (Camellia sp.) to exogenous application of ascorbic acid

Effects of exogenous application of ascorbic acid on physiological and metabolic changes in tea were investigated in the present study. The highest improvement in yield was evident in response to regular application (a day after every harvest) of ascorbic acid at 600 ppm followed by 400 ppm. Foliar application of ascorbic acid (600 ppm) at regular intervals enhanced chlorophyll a and b contents besides a significant increase in total polyphenols and catechins when compared to the untreated control. Exogenous application of ascorbic acid at alternate harvesting rounds increased the activity of polyphenol oxidase whereas ascorbate peroxidase remained unchanged. An increase in phenylalanine ammonia lyase activity was noticed with foliar application of ascorbic acid irrespective of its concentrations. Theaflavins and thearubigins of made tea showed an increase when ascorbic acid was applied with 400 and 600 ppm at alternate intervals. The scores of brewed tea liquor characteristics, viz. infusion, color, strength, and briskness were higher even at the lower concentration of ascorbic acid treatment. Results suggest that foliar application of ascorbic acid (400 ppm) proved to be a useful measure to improve the yield, physiological attributes, and antioxidant properties of tea.

Effect of Picloram on Somatic Embryogenesis from Leaf-sheath Explants in Diploid Musa acuminata cv. Njalipoovan

Embryogenic callus was obtained from leaf sheath explants on MS supplemented with 16.56 μM picloram in Musa acuminata (diploid) cv. Njalipoovan (AB). Exogenous application of ascorbic acid on somatic embryogenesis at optimal level accelerated the conversion rate of the embryos. Shoot and root developed from the embryos on MS incubated in dark. Further growth of plantlets obtained on half strength of MS under light conditions. Regenerated plantlets showed 100% survival. Key words: Musa acuminata cv. Njalipoovan, Picloram, Somatic embryogenesis D. O. I. 10.3329/ptcb.v21i1.9612 Plant Tissue Cult. & Biotech. 21(1): 83-87, 2011 (June) - Short communication

Effect of exogenous application of ascorbic acid on antioxidant enzyme activities, proline contents, and growth parameters of Saccharum spp. hybrid cv. HSF-240 under salt stress

The present study was undertaken to examine the effects of exogenous application of ascorbic acid (AA) through different modes on growth and associated biochemical parameters in Saccharum spp. hybrid cv. HSF-240, under salt stress. In a pot experiment, AA was applied through irrigation or foliar-spray at the concentrations of 0.1, 0.5, and 1 mM with or without 100 mM NaCl concentration. Vegetative growth measurements, antioxidant enzyme activities (POD and SOD), and protein and proline contents of plants were recorded to study the effects of these treatments. The presence of salt reduced the growth of sugarcane plants. The AA application not only mitigated the inhibitory effects of salt stress but also induced a stimulatory effect on all the studied growth parameters. The activities of antioxidant enzymes (POD and SOD) as well as proline contents of plants were increased, although the protein contents were decreased after AA application. The exogenous application of AA through either way significantly alleviated the adverse effects of salinity on growth and biochemical parameters of sugarcane plants. However, in this study, the AA application through irrigation proved to be a better option in mitigating the adverse effects of salinity.

Heat-stress induced inhibition in growth and chlorosis in mungbean (Phaseolus aureus Roxb.) is partly mitigated by ascorbic acid application and is related to reduction in oxidative stress

The rising temperatures (>35°C) are proving detrimental to summer-sown mungbean genotypes that experience inhibition of vegetative and reproductive growth. In the present study, the mungbean plants growing hydroponically at varying temperatures of 30/20°C (control), 35/25, 40/30, and 45/35°C (as day/night 12 h/12 h) with (50 μM) or without ascorbic acid (ASC) were investigated for effects on growth, membrane damage, chlorophyll loss, leaf water status, components of oxidative stress, and antioxidants. The ASC-treated plants showed significant improvement in germination and seedling growth especially at 40/30 and 45/35°C. The damage to membranes, loss of water, decrease in cellular respiration, and chlorophyll were significantly prevented by ASC treatment to plants growing at these temperatures. The oxidative stress measured as malondialdehyde and hydrogen peroxide content was observed to be significantly lower at high temperatures with ASC application. The activities of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase increased at 40/30°C but decreased at 45/35°C in the absence of ASC while with its application, the activities of these enzymes were appreciably resorted. Among all the antioxidants, the endogenous ASC content decreased to the greatest extent at 45/35°C grown plants indicating its vital role in affecting the response of mungbean to heat stress. Exogenously applied ASC raised its endogenous content along with that of glutathione and proline at 45/35°C. The findings indicated that heat stress-induced inhibition in growth and chlorosis was associated with decrease in leaf water status and elevation of oxidative stress, which could partly be prevented by exogenous application of ASC. Its role in imparting protection against heat stress is discussed.

Heat shock-induced ascorbic acid accumulation in leaves increases cadmium tolerance of rice (Oryza sativa L.) seedlings

Ascorbic acid (AsA) is the most abundant antioxidant in plants and plays a role in responding to oxidative stress. It has been shown that AsA plays a role in protecting against abiotic stresses. Rice seedlings stressed with 5 μM CdCl2 showed typical Cd toxicity (chlorosis and increase in malondialdehyde content). Rice seedlings pretreated with heat shock at 45°C (HS) or H2O2 under non-HS conditions resulted in the increase in ascorbic acid (AsA) content and the AsA/dehydroascorbate ratio in rice leaves. Exogenous application of AsA or L-galactonone-1, 4-lactone (GalL), a biosynthetic precursor of AsA, under non-HS conditions, which resulted in an increase in AsA content in leaves, enhanced subsequent Cd tolerance of rice seedlings. Pretreatment with imidazole, an inhibitor of NADPH oxidase, under HS conditions significantly decreased H2O2 and AsA contents in leaves and reduced subsequent Cd tolerance of rice seedlings. We also observed that pretreatment with lycorine, which is known to inhibit the conversion of GalL to AsA, significantly inhibited HS-induced AsA accumulation in leaves and reduced HS-induced protection against subsequent Cd stress of rice stress. It appears that HS- or H2O2-induced protection against subsequent Cd stress of rice seedlings is mediated through AsA. The time-course analyses of HS in rice seedlings demonstrated that the accumulation of H2O2 preceded the increase in AsA. Based on the data obtained in this study, it could be concluded that the early accumulation of H2O2 during HS signals the increase in AsA content, which in turn protects rice seedlings from oxidative damage caused by Cd.

ASCORBIC ACID AND TISSUE BROWNING IN MANGO CV HINDI BE-SENNARA FRUITS (Mangifera indica L.) UNDER COLD STORAGE

This study was conducted to find out the relationship between ascorbic acid (AA), and internal browning (IB) incidence in Hindi Be-sennara mango fruits (Mangifera indica L.) during cold storage (4oC). Ascorbic acid content in two main parts (stem and calyx end of fruit) and three sub-main parts (peels, inner and outer pulps) of the fruits were measured. Internal browning in mango fruits found to be dependant on the fruit AA content. Exogenous application of AA (5.6 mM) decreased IB incidence when the fruits immersed for 24 hour compared to these immersed in water for the same time and stored at ambient conditions for 35 days. Mango fruits pre-storage immersing in diluted AA (5.6 mM), water is absorbed throughout the peel cells causing an increase on AA content and a decrease on its concentration. The decrease of IB incidence was appeared due to such increase on AA content in inner and outer parts of the fruit. This protection of the treated fruits may be related to the consumption of the externally added AA. Therefore, it could be said that the application of AA increases mango fruit quality, through protecting the from development of IB, also, the obtained results indicated that such treatment maintain the total phenols (TP) content in fruits during cold storage constant.

Impact of Exogenous Ascorbic Acid on Antioxidant Activity and Some Physiological Traits of Common Bean Subjected to Salinity Stress

The role of ascorbic acid as a key molecule antioxidant involves in biotic and abiotic stress has already been well described. Recent study indicates that it also participates in the detoxification of generated reactive oxygen species due to abiotic stresses. Thus, In order to study effects of salt stress and ascorbic acid on antioxidant enzyme activity, chlorophyll content, lipid peroxidation and abscisic acid accumulation of bean an experiment was conducted. The exogenous application of ascorbic acid in nutrition solution of bean plants indicated that later is involve in reduction of antioxidant enzyme activity and increase of resistance to salt stress. We observed that antioxidant enzyme activity increased due to salt stress and ascorbic acid via eliminating of reactive oxygen species decreased activities. Moreover, abscisic acid and lipid peroxidation were affected of salt stress. Increase of ascorbic acid concentration at 100 mM NaCl treatment prevented of lipid peroxidation and decreased generation of malondialdehyde as final product of peroxidation of membrane lipids. However, at high level of salinity, ascorbic acid did not significant effect on reduction of lipid peroxidation. Whereas, chlorophyll content decreased by reactive oxygen species. Ascorbic acid increased chlorophyll content at all of stressed and non-stressed treatments. Abscisic acid assay showed that, accumulation of this hormone increased under salt stress treatments and raise of ascorbic acid concentration in nutrition solution of stressed plants prevented of abscisic acid accumulation. Our data provide strong support to the hypothesis that exogenous of ascorbic acid reduces the harmful effects of salinity and increases resistance to salinity in bean plant.

Inducing Salt Tolerance in Wheat by Exogenously Applied Ascorbic Acid through Different Modes

ABSTRACT In order to assess whether exogenous application of ascorbic acid (AsA) through different ways could alleviate the adverse effects of salt-induced adverse effects on two wheat cultivars differing in salinity tolerance, plants of a salt tolerant (‘S-24’) and a moderately salt sensitive (‘MH-97’) cultivar were grown at 0 or 120 mM sodium chloride (NaCl). Ascorbic acid (100 mg L−1) was applied through the rooting medium, or as seed soaking or as foliar spray to non-stressed and salt stressed plants of wheat. Salt stress-induced reduction in growth was ameliorated by exogenous application of ascorbic acid through different ways. However, root applied AsA caused more growth enhancement under saline conditions. Leaf ascorbic acid, catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities were also maximal in salt stressed plants of both cultivars treated with AsA through the rooting medium. Furthermore, leaf ascorbic acid, CAT, POD, and SOD activities were higher in salt stressed plants of ‘S-24’ than those of ‘MH-97’. Root applied AsA caused more enhancements in photosynthetic rate. Root applied AsA caused more reduction in leaf sodium (Na+) compared with AsA applied as a seed soaking or foliar spray. Overall, AsA-induced growth improvement in these two wheat cultivars under saline conditions was cultivar specific and seemed to be associated with higher endogenous AsA, which triggered the antioxidant system and enhanced photosynthetic capacity.

Amelioration of salinity tolerance in Solanum tuberosum L. by exogenous application of ascorbic acid

The present investigation envisaged revealing the role of exogenous application of ascorbic acid in increasing resistance against NaCl stress. Shoot apices from 60-d-old, in vitro-grown plants of two commercially important cultivars of Solanum tuberosum L., cvs. Desiree and Cardinal, were inoculated on Murashige and Skoog (MS) medium supplemented with 0.5 mM ascorbic acid for 72 h as a pretreatment. Pretreated and non-pretreated shoot apices were transferred to MS medium containing different concentrations of NaCl (0-140 mM; eight treatments). Results were recorded for morphological (shoot length, shoot number, root length, root number, and number of nodes) and biochemical features (protein, peroxidase, catalase, and superoxide dismutase activities) after 60 d of salt treatment. Similarly, 60-d-old, well-proliferated callus cultures were also pretreated with ascorbic acid for 24 h and transferred to an optimized callus proliferation medium containing different concentrations of salt. Results were recorded after 60 d of salt treatment for percentage relative fresh weight growth and biochemical parameters. Salinity severely inhibited all the growth parameters in both the cultivars. Pretreatment with ascorbic acid to both salt-treated plants and callus cultures showed significant differences with respect to almost all of the growth and biochemical parameters studied. Protein content as well as catalase and superoxide dismutase activities increased significantly in both the cultivars, although peroxidase activity showed a decreasing trend in ascorbic acid-pretreated plants as well as callus cultures.

Exogenously applied ascorbic acid alleviates salt-induced oxidative stress in wheat

Although ascorbic acid (AsA) is one of the most important and abundantly occurring water soluble antioxidants in plants, relatively little is known about its role in counteracting the adverse effects of salt stress on plant growth. To address this issue that whether exogenous application of ascorbic acid (AsA) through rooting medium could alleviate the adverse effects of salt stress on wheat plants, a hydroponic experiment was conducted under glasshouse conditions using two wheat cultivars, S-24 (salt tolerant) and MH-97 (moderately salt sensitive). Plants of both cultivars were subjected to 0 or 150 mM NaCl solution supplemented with 0, 50, or 150 mg L −1 AsA for 58 days. Imposition of salt stress reduced the growth of both wheat cultivars by causing reduction in photosynthesis, and endogenous AsA level, and enhancing accumulation of Na + and Cl − coupled with a decrease in K + and Ca 2+ in the leaves and roots of both cultivars thereby decreasing tissue K +/Na + ratio. However, root applied AsA counteracted the adverse effects of salt stress on the growth of cv. S-24 only, particularly at 100 mg L −1 AsA level. AsA-induced enhancement in growth of salt-stressed plants of S-24 was associated with enhanced endogenous AsA level and CAT activity, and higher photosynthetic capacity, and accumulation of K + and Ca 2+ in the leaves. Although root applied AsA did not improve the growth of salt-stressed plants of MH-97, it enhanced endogenous level of AsA, CAT activity, photosynthetic capacity, and leaf K + and Ca 2+. These findings led us to conclude that root applied AsA counteracts the adverse effects of salt stress on growth of wheat by improving photosynthetic capacity of wheat plants against salt-induced oxidative stress and maintaining ion homeostasis, however, these effects were cultivar specific.

Ascorbate Oxidase Activity in Rice Shoot Apices during Panicle Initiation

There was a decrease in the ascorbate oxidase activity in the shoot apices of Oryza sativa L. cv BAM 11, a photo-sensitive rice variety. Ascorbic acid content in the shoot apex increased and exogenous application of ascorbic acid resulted in an earliness in panicle initiation. Photoperiodic treatment promoted panicle initiation with an early and faster decline in ascorbate oxidase activity. Decline in the activity of ascorbate oxidase showed a negative correlation with the increase in ascorbic acid content.