Effect of starvation on the genetic activity of nucleus and nucleolar organizer.
The investigations of root meristems and hypocotyls of Lupinus albus L. starved, and then fed with 2% sucrose were carried out and several variations in nuclear and nucleolar dimensions, their ultrastructure, template activity of DNA, activities of RNA polymerases and transcriptional activity, were found. As a result of starvation, the surface area of nuclei and nucleoli decreases several times; after 24 hours, in the presence of sucrose, it grows again, but the control state is not achieved. Moreover, in a starved material the area of condensed chromatin in nucleus is increased by 1/3; after feeding, its partial recovery to the initial state is observed. The intensity of binding of 3H AMD in a fed material is increased by 1/3 as compared with the starved one. Transcriptional activity, estimated on the basis of 3H uridine incorporation is decreased in a starved material, especially in the meristematic tissue; feeding intensificates the transcriptional activity whereas the activity of endogenous RNA polymerase, investigated in hypocotyl, is drastically lowered in a starved material. Sucrose feeding does not restore the control state, though the per cent of nuclei and nucleoli revealing the activity of RNA polymerase is much higher in a fed material than in a starved one.
D002466:Cell Nucleolus / Q000378:metabolism* / Q000648:ultrastructure; D002467:Cell Nucleus / Q000502:physiology* / Q000648:ultrastructure; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D010944:Plants / Q000648:ultrastructure; D012313:RNA / Q000378:metabolism; D013217:Starvation; D013698:Templates, Genetic; D014158:Transcription, Genetic
D002843:Chromatin; D012313:RNA; D004247:DNA; D012321:DNA-Directed RNA Polymerases