tailieunhanh - Báo cáo y học: "The topless plant developmental phenotype explained"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: The topless plant developmental phenotype explained! | Minireview The topless plant developmental phenotype explained Karen S Osmont and Christian S Hardtke Address Department of Plant Molecular Biology University of Lausanne Biophore Building CH-1015 Lausanne Switzerland. Correspondence Christian S Hardtke. Email Published 30 April 2008 Genome Biology 2008 9 219 doi gb-2008-9-4-219 The electronic version of this article is the complete one and can be found online at http 2008 9M 219 2008 BioMed Central Ltd Abstract The molecular-genetic cues that regulate plant embryo pattern formation are the subject of intense scrutiny at present. Recent work in Arabidopsis implicates the TOPLESS protein in auxindependent transcriptional repression highlighting once again the crucial role of auxin signaling during embryogenesis. Biologists have long been fascinated by the question of how body patterns are specified during embryogenesis starting from an undifferentiated zygote. In animals embryogenesis typically lays down the adult body plan whereas in higher plants embryogenesis produces a minimal plant - the seedling. Consequently the vast majority of adult organs in plants are only initiated during post-embryonic growth. Nevertheless embryogenesis is of pivotal importance for adult plant development because post-embryonic growth is driven by pools of stem cells established during embryogenesis. These are laid down in the primary seedling meristems and yield the above- and below-ground structures such as leaves and roots of the adult. In the model plant Arabidopsis thaliana embryogenesis involves highly patterned and predictable cell divisions. The first zygotic division is asymmetric generating a smaller apical cell from which most of the embryo proper will be derived and a second basal cell that gives rise to the suspensor and part of the root meristem and cap 1 . A subsequent series of highly stereotypic divisions eventually leads to formation of embryonic tissues along a .