Modification of the radiosensitivity of barley seed by post-treatment with caffein. IV. Effect of the moisture content of seed and storage temperature after irradiation.
The oxygen-dependent damage which develops in barley seeds with approximately 7-8 per cent moisture content disappears after post-irradiation storage in vacuo for 48 hours at 40 degrees C and for 24 hours at 50 degrees C. When the diration of storage at 40 degrees C is extended to 384 hours, oxygen-independent damage becomes potentiated. There is oxygen-dependent damage in seeds of approximately 13.3 per cent moisture content and after the seeds have been stored in vacuo at 50 degrees C, the oxygen-dependent damage begins to increase by 168 hours, and it is very significantly potentiated by 192 hours. Under these circumstances, caffeine acts as a radioprotector only as long as the precursors of oxic damage are present in the seeds. Once these sites are lost, caffeine acts only as a radiosensitizer. The oxygen-independent damage which increases with storage at high temperature is further potentiated by caffeine.
D002110:Caffeine / Q000494:pharmacology*; D003037:Cobalt Radioisotopes; D005720:Gamma Rays; D010100:Oxygen; D011837:Radiation-Protective Agents / Q000494:pharmacology; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology; D012639:Seeds / Q000187:drug effects / Q000528:radiation effects*; D013696:Temperature
D003037:Cobalt Radioisotopes; D011837:Radiation-Protective Agents; D011838:Radiation-Sensitizing Agents; D002110:Caffeine; D010100:Oxygen