• Korean Journal of Environmental Biology
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• v.19 no.3
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• pp.205-210
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• 2001

To determine the effect of low dose gamma radiation on the germination and enzyme activities, seeds of Chinese cabbage (Brassica compestris L. cv. Hanyoreum) and radish (Raphanus sativus L. cv. Chungsukoungzoung) were irradiated at the dose of 2-50 Gy. The germination rate of irradiation group was higher than that of the control. Especially it was highest at the early stage. The germination rate of Chinese cabbage was high at 2 Gy and 8 Gy irradiation group and that of radish was high at 2 Gy, 6 Gy and 10 Gy irradiation group. Growth of both seedlings of Chinese cabbage and radish increased positively in low dose irradiation group. The height of Chinese cabbage was noticeably high at 4 Gy and 10 Gy irradiation group and that of radish at 6 Gy irradiation group. The protein contents of seedlings from seeds irradiated with the low dose gamma radiation was higher than the control, especially at the early stage. The enzyme activities of seedlings from seeds irradiated with the low dose gamma radiation was high at 4 Gy and 10 Gy irradiation group. These results suggest that the germination, growth and enzyme activities of old vegetable seeds could be promoted by the low dose gamma radiation.

• KSBB Journal
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• v.28 no.6
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• pp.415-422
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• 2013

Gamma irradiation (${\gamma}IR$) is widely used for radiotherapy as a treatment of cancer cells although it has a risk to damage normal cells. Inflammation is regarded as one of side effects of ${\gamma}IR$ while the effect of low dose of ${\gamma}IR$ on inflammation has not been researched well. Here, we investigated the inflammatory responses of low dose of ${\gamma}IR$ on murine spleen cells. It was evaluated if ${\gamma}IR$ affected the mitogen-induced lymphocyte proliferation, the regulation of various inflammatory cytokines (IFN-${\gamma}$, IL-2, IL-17, IL-4, IL-10), and the involvement of Ikaros and MAPK/NF-${\kappa}B$ medicated mechanism. Exposure of $^{137}Cs-{\gamma}IR$ below 2 Gy decreased the lymphocytes proliferative response to mitogens (LPS, ConA) except at the lowest dose, 0.05 Gy. IL-17, IL-2 and IL-4 mRNA increased at 0.5 and 2 Gy, but not altered at 0.05 Gy. IL-10, anti-inflammatory cytokine, increased only at 0.05 Gy. In regard to intracellular signaling, p-JNK, p-p38 and p-$I{\kappa}B{\alpha}$ were not changed, whereas the activation of ERK and Ikaros increased at the lowest dose. These results suggest that exposure of ${\gamma}IR$ less than 0.5 Gy (or below 0.05 Gy) has beneficial effects as a radiation hormesis on immune function.

• Journal of Microbiology and Biotechnology
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• v.12 no.6
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• pp.1010-1012
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• 2002

In order to isolate carotenoid-hyperproducing yeast, low-dose gamma irradiation was used as means of mutagenesis. Phaffia rhodozyma was treated by gamma irradiation of less than 10 kGy, which is considered to be a wholesome irradiation condition established by the Food and Drug Administration. Through repeated rounds of gamma irradiation and visual screening, mutant 3A4-8 was obtained. It produced a $3,824{\mu}g$ carotenoid/g yeast, 69% higher content than $2,265{\mu}g/g$ yeast of the unirradiated one. This result indicates that low-dose gamma irradiation could be used as means of mutagenesis to obtain carotenoid-hyperproducing strain of Phaffia rhodozyma, since only carotenoid-hyperproducing yeast survived gamma irradiation by scavenging oxygen radicals generated by radiolysis of water.

• Korean Journal of Environmental Biology
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• v.20 no.3
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• pp.197-204
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• 2002

Gourd seeds were irradiated with the doses of 0-20 Gy to investigate the effect of the low dose $\gamma$-radiation on the early growth and physiological activity. The stimulating effects of the low dose y- radiation on the early growth were not noticeably high, but were increased generally at 4-16 Gy irradiation group. The catalase and peroxidase activity of cotyledon from seeds irradiated with $\gamma$- radiation were increased at 8 Gy irradiation group. The photochemical activity of leaf was noticeably high at 4 Gy irradiation group. The photochemical yield of PSII, estimated as Fv/Fm, decreased with increasing illumination time by 50% after 4 hrs in the control and 8 Gy irradiation group, while Fo slightly increased. However, Fv/Em in the 4 Gy irradiation group decreased by 40% of inhibition, indicating that photoinhibition decreased by the low dose $\gamma$- radiation. Changes in the effective quantum yield of PSII, $\varphi_{PSII}$ and 1/Fo- l/Fm, a measure of the rate constant of excitation trapping by the PSII reaction center, showed similar pattern to Fv/Em. NPQ decreased by 70% after photoinhibitory treatment with showing similar pattern between the control and the irradiation group. These results showed the positive effect of low dose $\gamma$- radiation on the seedling growth and the reduction of photoinhibition in the 4 Gy irradiation group.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.270-277
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• 2001

To observe the stimulating effect of low dose ${\gamma}$ radiation on the dormancy breaking and growth, microtubers induced in vitro of two potato (Solanum tuberosum L. cv. Dejima and cv. Superior) cultivars with different storage duration were irradiated with ${\gamma}$ radiation at the dose of $0.5{\sim}30$ Gy. Sprouting rate, growth and tuber yield of ‘Dejima’ microtuber were increased by ${\gamma}$ radiation in the range of $2{\sim}16$ Gy. In the microtuber of ‘Superior’, the sprouting rate was promoted by 2 Gy and 4 Gy irradiation, and the growth and tuber yield by 0.5 Gy and 4 Gy irradiation. There were not that much difference in chlorophyll content of potato plantlet by the low dose ${\gamma}$ irradiation. These results suggested that low dose ${\gamma}$ radiation stimulated the dormancy breaking and potato growth.

• Journal of Radiation Protection and Research
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• v.24 no.3
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• pp.123-129
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• 1999

Tomato (Lycopericum esculentum $M_{ILL}$ cv. Seokwang and cv. Housemomotaro) seeds were irradiated with the doses of $1{\sim}20$ Gy from $^{60}Co$ $\gamma$-ray source to investigate the effect of the low dose $\gamma$-ray radiation on the early growth and resistance to subsequent high dose of radiation. Germination rate of seeds irradiated with low dose $\gamma$-ray was enhanced in Seokwang cultivar but not in Housemomotaro cultivar. Seedling height increased in 4 Gy and 8 Gy irradiation group of both cultivars. Plant height of Seokwang cultivar was depressed in low dose irradiation group but fresh weight was increased in 2 Gy and 4 Gy irradiation group. In Housemomotaro cultivar, plant height increased in 12 Gy and 20 Gy irradiation group and fresh weight increased in 4 Gy and 20 Gy irradiation group. Growth inhibition of tomato plants by high dose radiation was noticeably reduced by pre-irradiation of low dose radiation. Resistance to subsequent high dose of radiation was enhanced in 2 Gy and 8 Gy Irradiation group of Seokwang cultivar and in 2 Gy and 12 Gy irradiation group of Housemomotaro cultivar.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.410-414
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• 1995

Adaptive response induced by low dese .gamma.-ray irradiation in human cervical carcinoma cells was examined. Cells were exposured to low dose of .gamma.-ray irradiation in human cervical carcinoma cells was examined. Cells were exposured to low dose of .gamma.-ray (1-cGy) followed by high doses of r-ray irradiation (0,1,2,3,5,7 and 9Gy for chlnogenic assay or 1.5Gy for micronucleus assay) with various time intervals. Survival fractions of cells in both low dose-irradiated and unirrated groups were analyzed by clonogenic assay. Surviva fractions of low dose-irradiated in cell survival was maximum when low and high dose irradiation time interval was 4 hr. Frequencies of micronuclei which is an indicative of chromosome aberration were also enutained from survival fractions analyzed by clonogenic assay, maximum when low and high dose irradiation time interval was 4hr. Frequencies of micronuclei which is an indicative of chromosome aberration were also enumerated in both low dose-irradiated and unirradiated groups. In consiststent with the result obtained from survival fractions analyzed by clonogenic assay, maximum reduction in frquencies of micronuclei was observed when low dose radiation was given 4 hr prior to high response to subsequent high dose .gamma.-ray irradiation in human cervical carcinomal cells. Our data suggest that one of the possible mechanisms of adaptive response induced by low dose rediation is the increase in repair of DNA double strand breaks in low dose radiation-adapted cells.

• Journal of Photoscience
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• v.9 no.2
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• pp.397-399
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• 2002

The seedling height, leaf width and leaf length of pepper increased in plants grown from seeds irradiated with the low dose of 4 Gy. The $O_2$ evolution in the 4 Gy irradiation group was 1.5 times greater than the control. Pmax was decreased with increasing illumination time by 20% in the control, while hardly decreased in the 4 Gy irradiation group. Fv/Fm was decreased with increasing illumination time by 50% after 4 hours, while Fv/Fm in the 4 Gy irradiation group was decreased by 37% of inhibition, indicating that the low dose $\gamma$ radiation increased resistance of plants to photoinhibition.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.324-327
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• 2000

Soybean (Glycine max L. cv. Hwangkeum) seeds were irradiated with the dose of $0{\sim}20$ Gy to investigate the effect of the low dose ${\gamma}-ray$ radiation on the early growth and resistance to subsequent high dose of radiation. Germination rate was not enhanced in the seeds irradiated with low dos ${\gamma}-ray$ but plant height and fresh weight increased in the low dose irradiation group. The optimal radiation dose for the growth increasing was 8 Gy in soybean plant. Growth inhibition of soybean plants by high dose radiation was noticeably reduced by pre-irradiation of low dose radiation, Resistance to subsequent high dose of radiation was effective in 8 Gy and 20 Gy irradiation group.

• Food Science of Animal Resources
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• v.31 no.6
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• pp.843-850
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• 2011

This study investigated the effect of low dose ${\gamma}$-irradiation on the damage of the cell envelopes and antibiotic sensitivity profiles of Bacillus cereus, Escherichia coli, and Salmonella Typhimurium. The bacteria suspension in tryptic soy broth was exposed to the ${\gamma}$-irradiation doses of 0, 1, 1.5, 3, and 5 kGy, and then stored at $0^{\circ}C$ for 24 h. A viability test, an antimicrobial sensitivity profile, and an electron microscopy were performed to observe the effects due to ${\gamma}$-irradiation treatment. B. cereus could survive the ${\gamma}$-irradiation up to 5 kGy while E. coli and S. Typhimurium were all deactivated at 1.5 kGy and 5 kGy, respectively. At 5 kGy, the cell count of B. cereus was significantly reduced, and the survived bacteria cells retained their important features. There were no significant changes observed in the antimicrobial sensitivity profile (p>0.05) for the recovered bacteria after irradiation treatment. Low dose ${\gamma}$-irradiation below 3 kGy was found to be insufficient to achieve decontamination of B. cereus and S. Typhimurium. Cell envelope damage and deactivation of different bacteria did not occur in the same manner; thus, deferent doses of ${\gamma}$-irradiation may be required for deactivation of different bacteria.