The effect of ionizing radiation on ribosomal RNA synthesis in grand rapids lettuce seeds

Yealy, Lynn P.; Stone, B. P.

doi:10.1016/s0033-7560(75)80003-2

Cited by 5 publications

(5 citation statements)

References 22 publications

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“…With the decrease in mean DNA content per cell, there is a simultaneous decrease in the rate of RNA turnover, and this reduction is also dose dependent in all the three species, except for some mutagen treatments. Such an induced decrease in RNA synthesis has been reported in irradiated seeds of lettuce (Yealy and Stone 1975). It has been suggested that the inhibition of RNA synthesis is associated with the de crease in germination due to mutagen treatments which might have destroyed the ribosomes; the radiation induced inhibition of seed germination might be either due to destruction of ribosomes (Van Huystee et al 1968) or because of ribosomal genes.…”

Section: Discussionmentioning

confidence: 88%

Nuclear DNA and RNA amounts in the wild and cultivated urd and mung beans and their M1 plants.

Ignacimuthu

Babu

1988

cytologia

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Recent advances on the molecular probing of the structure and organisation of complex eukaryotic genomes coupled with the cytogenetical analysis revealed the existence of bewilder ing complexity in the eukaryotic genome above one gene level (Dover et al. 1982). An un derstanding of the organisation of eukaryotic genome not only paves the way for elucidating genome evolution and speciation, but also enables us to explain how the total phenotype is influenced by the different facets of genome structure and organisation (Flavell 1982). Various reports so far indicate that chromosomal DNA amount is changeable to some extent within a species (Jones and Rees 1968, Ayonoadu 1974, Belford and Thompson 1981, Nagato et al. 1981, Yamamoto and Nagato 1984. Although enough reports are there with regard to the DNA amounts in various crops (Nagato et al. 1981, Resslar et al. 1981) not much work has been done on the mutant lines. In the present investigation, we examined the variation of DNA and RNA amounts in Vigna sublobata (Roxb.) Babu and Sharma (wild), V. radiata (L.) Wilczek and V. mungo (L.) Hepper (cultivars) along with their M1 generation plants to un derstand the mechanism of mutational action in the wild and cultivated species and its role in plant evolution and domestication. Materials and methodsSeeds of Vigna radiata cv. PS 16, V. mungo cv. T 9 (obtained from Pulse Research Labo ratory, IARI, New Delhi) and V. sublobata (harvested from the garden-grown progenies of a natural population collected from Palney Hills of Western Ghats, Tamilnadu) were used for the induction of mutations. Ethylmethane sulphonate (EMS) and gamma rays were used as mutagens. The dose of the physical mutagen was expressed as kilorads. Three mutagenic treatment-EMS alone, gamma rays alone and EMS+gamma rays combined-were employed. The dose treatments of EMS, gamma rays and EMS+gamma rays applied were: 0.1%, 0.2%, 0.3% and 0.4%, 10KR, 20KR, 30KR and 40KR, and 0.1%+10KR, 0.2%+20KR, 0.3%+30KR and 0.4%+40KR, respectively. EMS was dissolved in distilled water and the seeds were soaked in the aqueous solution of appropriate concentration for 10h, after 6h of pre-soaking in distilled water. The treated seeds were thoroughly washed in running water for 12h and the excess moisture was blotted off. The moisture content of the seed, before mutagen treatment, was adjusted to 10.5-11.0% by differential drying in an air oven. 60Co was used as the source of gamma rays for the irradiation of seeds, which was carried out at the irradiation unit of IARI, New Delhi, at a dose rate of 2500 rads min-1. For the com bined treatment, the seeds were first irradiated with gamma rays and then treated with EMS; a control was also maintained. Two replicates of 150 seeds each were sown in the field for each dose treatment in a randomized block design. Seeds from each plant of M1 generation were harvested separately and used for the analysis of DNA and RNA content.Feulgen cytophotometric method was used for the in situ localization of 2C DNA amount

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Section: Discussionmentioning

confidence: 88%

Nuclear DNA and RNA amounts in the wild and cultivated urd and mung beans and their M1 plants.

Ignacimuthu

Babu

1988

cytologia

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“…The inhibitory effects of ionizing radiation on hypocotyl elongation may be similar in action to those on germination (Yealy and Stone 1975) since both are essentially processes of cell elongation. Ionizing radiation decreased hypocotyl length with increasing dose which was evident in darkness ( Figure 2) but much less obvious in light (Figure 1) due to the inhibitory effects of continuous light.…”

Section: Discussionmentioning

confidence: 99%

“…of Tenn.). In previous studies (Yealy and Stone 1975) this delay was shown to be associated with the time required for repair processes involving the synthesis of ribosomal RNA which was destroyed by prior exposure to gamma irradiation. The present study describes experiments designed to determine the effects of ionizing radiation on lettuce hypocotyl elongation in conjunction with GA and FU.…”

Section: Introductionmentioning

confidence: 93%

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The Effect of Gamma‐Irradiation on Lettuce Seedling Elongation

Yealy¹,

Stone²

1976

Physiologia Plantarum

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This study was initiated to determine the effects of gammairradiation on lettuce hypocotyl elongation and ribosomal RNA synthesis relative to gibberellic acid and 5-fiuorouracil treatment. Exposure of seeds to gamma-irradiation inhibited hypocotyl elongation of seedlings grown in continuous light and darkness. The presence of 5-fiuorouracil in the incubation medium significantly retarded hypocotyl elongation; however, gibberellic acid was stimulatory to elongation in seedlings grown from irradiated and unirradiated seeds. The synthesis of ribosomal RNA was selectively depressed by 5-fluorouracil while gibberellic acid stimulated incorporation of ^H-uridine into ribosomal and transfer RNA. The observed response implies that ionizing radiation is effective in decreasing the synthesis of ribosomal and transfer RNA which is correlated with lettuce hypocotyl elongation.

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“…The biopositive effects of ionizing radiation and UV-light are mostly called "stimulation". Similar or higher radiation doses stimulate also biochemical processes such as polysome formation [9], enzyme activities [22], phenol synthesis [15] and RNA synthesis [26,29]. The applied dose rates varied between less than 0.01 Gy/s and 1000 Gy/s [17].…”

Section: Introductionmentioning

confidence: 99%

Tube growth stimulation of pine pollen by low doses of irradiation. Dose rate, reproducibility and comparison between UV-light and ionizing rays

Seibold

Zelles

Ernst

1979

Radiat Environ Biophys

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Stimulation of the tube growth of pine pollen by low doses of UV-light or X-rays is a reproducible process, but it depends strongly of the dose rate applied. It can be proved that the observed effect is more determined by dose rate and irradiation time than by the dose itself which can vary by nearly one order of magnitude for achieving the same increase in tube elongation. The range of absorbed energy at which the stimulation effect can be observed is rather broad and overlapping between UV and X-rays. In the average the UV-energy needed is 5 times higher than X-ray energy.

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The effect of ionizing radiation on ribosomal RNA synthesis in grand rapids lettuce seeds

Cited by 5 publications

References 22 publications

Nuclear DNA and RNA amounts in the wild and cultivated urd and mung beans and their M1 plants.

Nuclear DNA and RNA amounts in the wild and cultivated urd and mung beans and their M1 plants.

The Effect of Gamma‐Irradiation on Lettuce Seedling Elongation

Tube growth stimulation of pine pollen by low doses of irradiation. Dose rate, reproducibility and comparison between UV-light and ionizing rays

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