Premium
A CYTOPHOTOMETRIC STUDY OF NUCLEIC ACIDS AND PROTEINS IN THE SHOOT APEX OF WHITE SPRUCE
Author(s) -
Cecich Robert A.,
Lersten Nels R.,
Miksche Jerome P.
Publication year - 1972
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1972.tb10115.x
Subject(s) - primordium , biology , apex (geometry) , histone , dna , botany , nucleic acid , rna , etiolation , ontogeny , microbiology and biotechnology , biochemistry , genetics , gene , enzyme
During the annual three‐phase growth cycle of white spruce [ Picea glauca (Moench) Voss] the vegetative shoot apex changed in anatomical configuration. Relative amounts of DNA, histones, RNA, and proteins were measured in three cytohistological zones and were related to the anatomical changes during ontogeny. An extended period of DNA synthesis (S) and G 2 preceded an increase in the number of apical initial cells which were part of the mammillary apex. While DNA and histones were generally synchronous during ontogeny, the ratio of DNA to histone increased on June 20. This loss of histone and subsequent increases in RNA and cytoplasmic proteins preceded the appearance of needle primordia on next year's apex. We propose that induction of the apex to reorganize and form needle primordia occurred when the DNA was in a 2C condition, following the loss of histone on June 20.