Related Experiment Video
Updated: May 5, 2026

Non-radioactive in situ Hybridization Protocol Applicable for Norway Spruce and a Range of Plant Species
Published on: April 17, 2009
A tracheid-differentiation factor from pine needles
1Department of Botany and Microbiology, University College of Wales, SY23 3DA, Aberystwyth, Dyfed, U.K..
Abstract:
Exogenous indol-3yl-acetic acid (IAA), alone and together with several cytokinins, was ineffective in promoting the complete differentiation into tracheids of cambial derivatives of Pinus contorta Dougl.; IAA alone promoted cambial cell division and primary-wall growth in cambial derivatives throughout the stem's length. In contrast, a single pair of needles on a stem cutting in light promoted neither cambial cell division nor primary-wall growth in cambial derivatives but did promote complete differentiation of cambial cells into tracheids; tracheids differentiated only near the junction of the foliated short shoot with the stem. Clear inter-and intracellular differences in the extent of tracheid differentiation occurred in response to a single needle pair and have suggested the hypothesis that a specific tracheid-differentiation factor regulates the differentiation of cells into proto-, meta-, or secondary-xylem tracheary elements through an interaction with IAA.
Related Concept Videos
The Bronchial Tree
The trachea, commonly known as the windpipe, is a tube that connects the larynx (voice box) to the bronchi. At a point called the carina, it bifurcates into two primary bronchi. The right primary bronchus is wider, shorter, and more vertical than the left primary...
Forced Transdifferentiation
Artificial...
Primary and Secondary Growth in Roots and Shoots
Cellular Differentiation
A zygote is a...
Morphogenesis
Cell Signaling in Plants

