Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 15653401

Networks in leaf development.

Mary E Byrne
View original source ↗Export metadata ↓

Abstract

Shoots are characterized by indeterminate growth resulting from divisions of undifferentiated cells in the central region of the shoot apical meristem. These cells give rise to peripheral derivatives from which lateral organ initials are recruited. During initial stages of cell recruitment, the three-dimensional form of lateral organs is specified. Lateral organs such as leaves develop and differentiate along proximodistal (base-to-tip), dorsoventral (top-to bottom) and mediolateral (middle-to-margin) planes. Current findings are refining our knowledge of the genes and genetic interactions that regulate these early processes and are providing a picture of how these pathways may contribute to variation in leaf form.

Explore related subjects

Gene Expression Regulation, DevelopmentalGene Expression Regulation, PlantMeristemPlant LeavesSignal TransductionJournal ArticleReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Mary E Byrne. 2005. Networks in leaf development.. https://doi.org/10.1016/j.pbi.2004.11.009

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Developmental and embryo axis regulation of gibberellin biosynthesis during germination and young seedling growth of pea.

The expression patterns of five genes (PsGA20ox1, PsGA20ox2, PsGA3ox1, PsGA2ox1, and PsGA2ox2) encoding five regulatory gibberellin (GA) biosynthesis enzymes (two GA 20-oxidases, a GA 3beta-hydroxylase, and two GA 2beta-hydroxylases) were examined to gain insight into how these genes coordinate GA biosynthesis during germination and early postgermination stages of the large-seeded dicotyledonous plant pea (Pisum sativum). At the time the developing embryo fills the seed coat, high mRNA levels of PsGA20ox2 (primarily responsible for conversion of C20-GAs to GA(20)), PsGA2ox1 (primarily responsible for conversion of GA(20) to GA(29)), and PsGA2ox2 (primarily responsible for conversion of GA(1) to GA(8)) were detected in the seeds, along with high GA(20) and GA(29) levels, the enzymatic products of these genes. Embryo maturation was accompanied by a large reduction in PsGA20ox2 and PsGA2ox1 mRNA and lower GA(20) and GA(29) levels. However, PsGA2ox2 transcripts remained high. Following seed imbibition, GA(20) levels in the cotyledons decreased, while PsGA3ox1 mRNA and GA(1) levels increased, implying that GA(20) was being used for de novo synthesis of GA(1). The presence of the embryo axis was required for stimulation of cotyledonary GA(1) synthesis at the mRNA and enzyme activity levels. As the embryo axis doubled in size, PsGA20ox1 and PsGA3ox1 transcripts increased, both GA(1) and GA(8) were detectable, PsGA2ox2 transcripts decreased, and PsGA2ox1 transcripts remained low. Cotyledonary-, root-, and shoot-specific expression of these GA biosynthesis genes and the resultant endogenous GA profiles support a key role for de novo GA biosynthesis in each organ during germination and early seedling growth of pea.

Gene Expression Regulation, Developmental↗
PubMed2006

T-genes and limb bud development.

The T-box family of transcriptional factors is ancient and highly conserved among most species of animals. Haploinsufficiency of multiple T-box proteins results in severe human congenital malformation syndromes, involving craniofacial, cardiovascular, and skeletal structures. These genes have major roles in embryogenesis, including the development of the limbs. Formation of the limbs begins with a limb bud and its morphogenesis requires complex epithelial-mesenchymal interactions. Recent studies have shown that T, Tbx2, Tbx3, Tbx4, Tbx5, Tbx15, and Tbx18 are all expressed in the limb buds, and many have developmental functions. The study of these genes is clinically relevant as mutations in several of them cause human congenital malformation syndromes. Furthermore, understanding the function and biology of these genes is important in understanding normal embryogenesis.

Gene Expression Regulation, Developmental↗