Campus Units

Botany

Document Type

Article

Publication Version

Published Version

Publication Date

2-1977

Journal or Book Title

American Journal of Botany

Volume

64

Issue

2

First Page

207

Last Page

222

DOI

10.1002/j.1537-2197.1977.tb15720.x

Abstract

The morphology and anatomy of the shoot apex in germinating Pinus banksiana seeds is described by using scanning and transmission electron microscopy and microspectrophotometry, with special attention given to events preceding the appearance of the first leaf primordia at about 72 hr post‐imbibition. The 2C nuclei begin DNA synthesis at about 43 hr. RNA increases until 52 hr and is followed by a reduction related to cytokinesis. Protein drops after 36 hr, apparently related to digestion of storage protein bodies, which by 48 hr are about 50% digested. The resulting protein body vacuoles do not enlarge. Starch is digested just prior to appearance of the leaves and may be mediated by α‐amylase production from stacks of endoplasmic reticulum. Heterochromatin increases in the nuclei during germination and coincides with an increase in repeated nucleotide sequences. Golgi bodies increase in number after the first mitoses.

Comments

This article is published as Cecich, Robert A., and Harry T. Horner Jr. "An ultrastructural and microspectrophotometric study of the shoot apex during the initiation of the first leaf in germinating Pinus banksiana." American Journal of Botany 64, no. 2 (1977): 207-222. doi: 10.1002/j.1537-2197.1977.tb15720.x.

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Language

en

File Format

application/pdf

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