Enhancement of Regeneration Potential and Variability by γ-Irradiation in Cultured Cells of Scilla Indica
TL;DR: Induced mutagenesis in callus tissues was studied in the medicinal plant Scilla indica irradiated with different doses of γ-radiation and both diploid and mixoploid plants but no tetraploids were obtained.
Abstract: Induced mutagenesis in callus tissues was studied in the medicinal plant Scilla indica irradiated with different doses of γ-radiation ranging from 2.5 to 20 Gy. Low doses accelerated the cell division and growth rate of the tissues whereas high doses repressed growth rate and resulted in lethality of tissues. Various cytological and chromosomal abnormalities were observed in the irradiated calli, the degree of which depended upon the dosage. Low doses of irradiation also promoted the regenerating capacity of the calli tissues and plants regenerating from them exhibited better growth and vigour compared to normal plants. High doses led to loss of regenerating capacity and promoted formation of malformed and stunted plants. Cytological study of regenerants revealed both diploid and mixoploid plants but no tetraploids were obtained.
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TL;DR: Investigating alterations in the photosynthesis and antioxidant capacity of red pepper seedlings produced from gamma-irradiated seeds revealed that irradiation altered the compositions of photosynthetic pigments as well as the activities of antioxidant enzymes, however, these shifts were not directly related to the increase in early growth.
Abstract: To characterize the stimulatory effects of low-dose gamma radiation on early plant growth, we investigated alterations in the photosynthesis and antioxidant capacity of red pepper (Capsicum annuum L.) seedlings produced from gamma-irradiated seeds. For two cultivars (Yeomyung and Joheung), three irradiation groups (2, 4, and 8 Gy, but not 16 Gy) showed enhanced development, although Fv/Fm, the maximum photochemical efficiency of Photosystem II (PSII), did not differ significantly among any of the four groups. In contrast, values for 1/Fo — 1/Fm, i.e., a measure of functional PSII content, decreased in the irradiated groups of ‘Yeomyung’ but increased in those of ‘Joheung’. Pigment analyses and enzyme activity assays revealed that irradiation altered the compositions of photosynthetic pigments (chlorophylls and carotenoids) as well as the activities of antioxidant enzymes (superoxide dismutase and glutathione reductase). However, these shifts were not directly related to the increase in early growth, although they were cultivar-and developmental stage-dependent In addition, the effects of irradiation on the enzymatic activities measured here were at opposition between the two cultivars.
173 citations
TL;DR: The main results from studies on the effect of g-irradiations on plants, focusing on metabolic alterations, modifications of growth and development, and changes in biochemical pathways especially physio- logical behaviour are reported.
Abstract: Research on the basic interaction of radiation with biological systems has contributed to human society through various applications in medicine, agriculture, pharmaceuticals and in other technolog...
151 citations
Cites background from "Enhancement of Regeneration Potenti..."
...It has been reported that low level doses of g-irradiation enhance glutathione reductase activity (Chakravarty and Sen 2001)....
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TL;DR: The results demonstrate for the first time that the carotenoid pigments are the most radio-sensitive and fastest recovering compounds in plants, and that SOD, APX, and ascorbate are important inducible factors for improving stress resistance through the use of gamma-irradiation.
Abstract: We investigated the effects of low-dose inplanta irradiation on red pepper plants treated with gamma rays of 2, 4, 8, and 16 Gy. Growth was stimulated at 2 and 4 Gy but inhibited at 8 and 16 Gy. Photochemical quenching (qP) increased slightly in all treatment groups for 1 d after irradiation (DAl), whereas non-photochemical quenching (NPQ) decreased more noticeably. These changes in qP and NPQ were transient and had almost recovered to the control level by 2 DAl. Although carotenoid pigments also fluctuated during the experimental period, chlorophylls were almost entirely insensitive to the gamma rays. Irradiation also partially protected leaves from a decrease in photochemical efficiency (Fv/Fm) under conditions of UV-B (2.2 W m-2) and high light intensity (800 μmol m-2 s-1). This enhanced stress resistance could be partly explained by higher levels of SOD and APX activities, as well as ascorbate content. Our results demonstrate for the first time that the carotenoid pigments are the most radio-sensitive and fastest recovering compounds in plants, and that SOD, APX, and ascorbate are important inducible factors for improving stress resistance through the use ofin planta gamma-irradiation.
134 citations
TL;DR: In this article, the effect of various γ-irradiation doses (0, 5, 10, 15 and 20 G) on the enhancement of secondary metabolites production and antioxidant properties of rosemary callus culture was investigated.
Abstract: Effect of various γ-irradiation doses (0, 5, 10, 15 and 20 G) on the enhancement of secondary metabolites production and antioxidant properties of rosemary callus culture was investigated. The obtained data showed a highly metabolic modification of chemical constituents and various antioxidant defense enzymes (APX, CAT, SOD and GR), which gradually increased in response to radiation doses, while reduced (GSH), ascorbic acid (AsA) contents, total soluble protein, total soluble amino acids, total soluble sugars and PAL activity positively correlated with the increased doses. On the other hands the high irradiation levels significantly increased the accumulation of various oxidative burst (MDA, H2O2 and O2−). Meanwhile, higher doses of gamma irradiation positively enhanced secondary products accumulation of total phenols and total flavonoids in rosemary callus culture.
133 citations
TL;DR: Gamma irradiation increased biomass accumulation and seed yield in both treatments, and increased the chlorophyll content, photosynthetic activity, and activities of peroxidase and superoxide dismutase in drought-stressed soybean leaves.
Abstract: Drought stress is the main limiting factor in soybean production. However, no work has been done on how the application of a low dose of gamma rays could help to overcome water deficits during critical stages of soybean development. Gamma rays at a dose of 20 Gray (Gy) were applied to dry seeds of soybean before planting. Two levels of soil moisture (80% field capacity for well-watered control and 35% for drought-stressed treatment) were applied at pod initiation. Gamma irradiation increased biomass accumulation and seed yield in both treatments. It also increased the chlorophyll content, photosynthetic activity (14CO2 fixation) and leaf water potential and enhanced the enzyme activities of RuBPCase and PEPCase of control plants compared with drought-stressed plants. Gamma irradiation (20 Gy) increased the soluble sugars, protein and proline content and the activities of peroxidase and superoxide dismutase in drought-stressed soybean leaves. It also increased the chloroplast size, which was reduced by dro...
75 citations
Cites background from "Enhancement of Regeneration Potenti..."
...Previous studies have shown that relatively low-doses ionizing irradiation on plants and photosynthetic microorganisms are manifested as accelerated cell proliferation, germination rate, cell growth, enzyme activity, stress resistance and crop yields (Chakravarty and Sen, 2001)....
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References
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TL;DR: In vivo redox biosensing resolves the spatiotemporal dynamics of compartmental responses to local ROS generation and provide a basis for understanding how compartment-specific redox dynamics may operate in retrograde signaling and stress 67 acclimation in plants.
Abstract: In experiments with tobacco tissue cultured on White's modified medium (basal meditmi hi Tnhles 1 and 2) supplemenk'd with kiticthi and hidoleacctic acid, a slrikin^' fourlo (ive-told intTease iu yield was ohtaitu-d within a three to Tour week j^rowth period on addition of an aqtteotis exlrarl of tobacco leaves (Fi^'ures 1 and 2). Subse(iueutly it was found Ihiit this jnoniotiou oi' f^rowih was due mainly though nol entirely to inorj^auic rather than organic con.stitttenls in the extract. In the isolation of Rrowth factors from plant tissues and other sources inorj '̂anic salts are fre(|uently carried along with fhe organic fraclioits. When tissue cultures are used for bioassays, therefore, il is necessary lo lake into account increases in growth which may result from nutrient elements or other known constituents of the medium which may he present in the te.st materials. To minimize interference trom rontaminaitis of this type, an altempt has heen made to de\\eh)p a nieditmi with such adequate supplies of all re(iuired tnineral nutrients and cotntnott orgattic cottslitueitls that no apprecial»le change in growth rate or yield will result from the inlroduclion of additional amounts in the range ordinarily expected to be present in tnaterials to be assayed. As a point of referetice for this work some of the culture media in mc)st common current use will he cotisidered briefly. For ease of comparis4)n Iheir mineral compositions are listed in Tables 1 and 2. White's nutrient .solution, designed originally for excised root cultures, was based on Uspeuski and Uspetiskaia's medium for algae and Trelease and Trelease's micronutrieni solution. This medium also was employed successfully in the original cttltivation of callus from the tobacco Iiybrid Nicotiana gtauca x A', tanijadorffii, atitl as further modified by White in 194̂ ^ and by others it has been used for the
63,098 citations
TL;DR: Variability among regenerated plants was also found after field testing and colchicine treatment was not effective for the production of tetraploid plants.
Abstract: Somaclonal and in vitro mutagen-induced variability was studied in grapevine. Plants of Vitis vinifera cv. Podarok Magaracha were regenerated from leaf explants through somatic embryogenesis. Chromosome counts of root tips was used for screening of regenerated plants. Among 242 studied plants, six (2.5%) tetraploids (2n=4x=76) were identified; all others were diploid (2n=2x=38). Neither chimeral, nor aneuploid plants were observed. Gamma-irradiation (5-100 Gy) increased tetraploid plant formation frequency of primary (7%) and embryogenic calluses (7.6%) and some aneuploid plants were also found. Colchicine treatment was not effective for the production of tetraploid plants. Variability among regenerated plants was also found after field testing.
89 citations
TL;DR: Irradiation may cause a shift from conditions favourable for callus growth to those favouring embryoid formation, and in media containing adenine, irradiation led to cessation of both callus Growth and embryoid Formation.
Abstract: Spiegel-Roy P. and Kochba J. Stimulation of differentiation in orange (Citrus sinensis) ovular callus in relation to irradiation of the media. Radiation Botany 13, 97-103, 1973.-Gamma irradiation of ovular callus of Shamouti orange ( Citrus sinensis ) caused a marked stimulation in embryoid formation at a dose of 16 kR. Doses of 28–32 kR proved lethal. Irradiation may cause a shift from conditions favourable for callus growth to those favouring embryoid formation. Irradiation of the medium, containing malt extract, caused as much embryoid stimulation as did irradiation of callus and medium. In media containing adenine, irradiation led to cessation of both callus growth and embryoid formation. With low kinetin and IAA, irradiation depressed callus growth and stimulated embryoid differentiation.
49 citations
Journal Article•
TL;DR: Out of four mutagens NMU was the most potent, while in the physical, gamma rays were more effective and efficient in inducing a high frequency and wide spectrum of chlorophyll mutations in the M2 followed by fast neutrons.
Abstract: Mutagenic effectiveness usually means the rate of mutation as related to dose. Mutagenic efficiency refers to the mutation rate in relation to damage. Studies on comparative mutagenic effectiveness and efficiency of two physical (gamma rays and fast neutrons) and two chemical mutagens (NMU and EMS) on two desi (G 130 & H 214), one kabuli (C 104) and one green seeded (L 345) chickpea (Cicer arietinum L.) have been reported. The treatments included three doses each of gamma rays (400, 500 and 600 Gy) and fast neutrons (5, 10 and 15 Gy) and two concentrations with two different durations of two chemical mutagens, NMU (0.01% 20h and 0.02% 8h) and EMS (0.1% 20h and 0.2% 8h). Results indicated that chemical mutagens, particularly NMU are not only more effective but also efficient than physical mutagens in inducing mutations in chickpea. Mutagenic effectiveness and efficiency showed differential behaviour depending upon mutagen and varietal type. Chemical mutagens were more efficient than physical in inducing cholorophyll as well as viable and total number of mutations. Among the mutagens NMU was the most potent, while in the physical, gamma rays were more effective. Out of four mutagens, NMU was the most effective and efficient in inducing a high frequency and wide spectrum of chlorophyll mutations in the M2 followed by fast neutrons. While gamma rays showed least effectiveness, EMS was least efficient mutagens. Major differences in the mutagenic response of the four cultivars were observed. The varieties of desi type were more resistant towards mutagenic treatment than kabuli and green seeded type.
25 citations