Campus Units

Agronomy, Botany, Zoology

Document Type

Article

Publication Version

Published Version

Publication Date

1993

Journal or Book Title

Canadian Journal of Botany

Volume

71

Issue

9

First Page

1153

Last Page

1168

DOI

10.1139/b93-136

Abstract

Photosynthesizing soybean plants were exposed to '"0, to study the incorporation of labeled water-insoluble photosynthates in ovules at various developmental stages. Using autoradiographic techniques on sectioned material, we show that the distribution of labeled carbon in different ovular tissues is regulated spatially and temporally. During zygote through globular stages of embryo development, labeled assimilates accumulate in integumentary tissue adjacent to the micropylar and chalazal poles of the embryo sac. A chalazal vascular trace and two adfunicular vascular strands are the pathways for accumulation of I4C in these regions. Up through the proembryo stage, movement of labeled photoassimilates into the lateral regions of the embryo sac seems blocked by a cuticle-like layer between the endothelium and embryo sac. At the globular embryo stage, the greatest accumulation of label is still at the chalazal and the micropylar ends of the embryo sac, but fragmentation of the cuticle-like barrier coincident with cellularization of endosperm allows channeling of labeled carbon from adjacent integumentary tissue into the embryo sac as well. Autoradiographic evidence for carbon flow into the embryo sac can be correlated with ultrastructural and morphological changes in time in ovular and endosperm tissues enclosing the embryo.

Comments

This article is published by Chamberlin, Mark A., Harry T. Horner, and Reid G. Palmer. "Nutrition of ovule, embryo sac, and young embryo in soybean: an anatomical and autoradiographic study." Canadian Journal of Botany 71, no. 9 (1993): 1153-1168. doi: 10.1139/b93-136.

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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