Biomaterial Database

Repair of radiation-induced single-strand breaks in DNA of barley embryo. 1977

S Tano, and H Yamaguchi

Repair of single-strand breaks induced by gamma-irradiation was studied in barley embryos. Nuclei were isolated from embryos at specified times after initiation of water absorption under different temperature conditions. From the shift of the peak of DNA in alkaline sucrose gradient, it was observed that clear repair of induced breaks occurred in the irradiated embryo during 2 h after soaking. However, this type of repair was not observed after 5 h up to 16 h, because natural degradation of DNA also occurred in the non-irradiated embryos. The estimated mol. wt. of DNA from the non-irradiated dry embryo was 0.93 X 10(-8) daltons; on the other hand, it was decreased to 0.15 X 10(-8) daltons by 30 kR of gamma-irradiation. This decreased mol. wt. recovered to 0.52 X 10(-8) daltons (64% recovery) after 2 h soaking at 25 degrees C. The repair observed in this experiment was not dependent on the regular synthesis of macromolecules, especially DNA.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA
D004307	Dose-Response Relationship, Radiation	The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.	Dose Response Relationship, Radiation,Dose-Response Relationships, Radiation,Radiation Dose-Response Relationship,Radiation Dose-Response Relationships,Relationship, Radiation Dose-Response,Relationships, Radiation Dose-Response
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D014158	Transcription, Genetic	The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.	Genetic Transcription