The control of embryogenic competence in Alfalfa (Medicago falcata L.)
type: CreativeWork
description: Somatic embryogenesis is a process by which somatic cells undergo a developmental sequence similar to that observed in zygotic embryos. This process is not only an important plant propagation technique, but it also provides an essential tool for basic research into plant embryo development and other aspects of plant physiology. One of the basic features of the initiation of somatic embryogenesis is the reactivation of the cell cycle and subsequent cell division in differentiated plant cells. The initiation of somatic embryogenesis effectively involves resetting an entire ontogenic program and presumably requires a substantial reprogramming of gene expression patterns. The reactivation of cell division may be an essential prerequisite for this genetic reprogramming. In this project, transgenic alfalfa plants carrying Arabidopsis cdc2a and, CycB1;1 promoter::gusA constructs, were used to investigate the activation of cell division during the induction of somatic embryogenesis. Promoter fragments of a sugar beet cdc2-like protein kinase gene (Bvcrk1-17. 26) fused to the gusA reporter gene were also introduced into alfalfa plants by Agrobaeterium-mediated transformation, to investigate their potential as molecular markers for re-entry into the cell division cycle. Histochemical assays of r,3 -glucuronidase (GUS) activity were carried out to investigate cell division activity patterns during direct somatic embryogenesis. The cell cycle inhibitors oryzalin and hydroxyurea were used to determine the relationship between the induction of cell division and somatic embryogenesis. The role of 2,4-D in the induction of cell division and somatic embryogenesis was also examined using these transgenic alfalfa lines. The expression patterns of the cell cycle promoter constructs in response to 2,4-D were compared with their behaviour in transgenic tobacco under the same conditions. Preliminary studies indicated that the response to 2,4-D induction treatment in activation of cell div…
abstract: Somatic embryogenesis is a process by which somatic cells undergo a developmental sequence similar to that observed in zygotic embryos. This process is not only an important plant propagation technique, but it also provides an essential tool for basic research into plant embryo development and other aspects of plant physiology. One of the basic features of the initiation of somatic embryogenesis is the reactivation of the cell cycle and subsequent cell division in differentiated plant cells. The initiation of somatic embryogenesis effectively involves resetting an entire ontogenic program and presumably requires a substantial reprogramming of gene expression patterns. The reactivation of cell division may be an essential prerequisite for this genetic reprogramming. In this project, transgenic alfalfa plants carrying Arabidopsis cdc2a and, CycB1;1 promoter::gusA constructs, were used to investigate the activation of cell division during the induction of somatic embryogenesis. Promoter fragments of a sugar beet cdc2-like protein kinase gene (Bvcrk1-17. 26) fused to the gusA reporter gene were also introduced into alfalfa plants by Agrobaeterium-mediated transformation, to investigate their potential as molecular markers for re-entry into the cell division cycle. Histochemical assays of r,3 -glucuronidase (GUS) activity were carried out to investigate cell division activity patterns during direct somatic embryogenesis. The cell cycle inhibitors oryzalin and hydroxyurea were used to determine the relationship between the induction of cell division and somatic embryogenesis. The role of 2,4-D in the induction of cell division and somatic embryogenesis was also examined using these transgenic alfalfa lines. The expression patterns of the cell cycle promoter constructs in response to 2,4-D were compared with their behaviour in transgenic tobacco under the same conditions. Preliminary studies indicated that the response to 2,4-D induction treatment in activation of cell div…
author: Zhou, Yan
license: https://dora.dmu.ac.uk/bitstreams/0ac3ca4d-79bc-4135-9b2d-c4ec46597f76/download
date published: 2004
date modified: 2026-07-24T06:18:54Z
provider: De Montfort University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: De Montfort University