David W Galbraith

David W Galbraith

Professor, Plant Science
Professor, Biomedical Engineering
Professor, BIO5 Institute
Primary Department
Department Affiliations
Contact
(520) 621-9153

Work Summary

I examine the molecular functions of the different cells found in the tissues and organs of plants and animals and how they combine these functions to optimize the health and vigor of the organism.

Research Interest

David Galbraith obtained undergraduate and graduate degrees in Biochemistry from the University of Cambridge, and postdoctoral training as a NATO Fellow at Stanford University. His first academic appointment was at the University of Nebraska Lincoln, and he became Professor of Plant Sciences at the University of Arizona in 1989. His research has focused on the development of instrumentation and methods for the analysis of biological cells, organs, and systems. He is internationally recognized as a pioneer in the development and use of flow cytometry and sorting in plants, developing widely-used methods for the analysis of genome size and cell cycle status, and for the production of somatic hybrids. He also was among the first to develop methods for the analysis of gene expression within specific cell types, using markers based on Fluorescent Protein expression for flow sorting these cells, and microarray platforms for analysis of their transcriptional activities and protein complements. Current interests include applications of highly parallel platforms for transcript and protein profiling of minimal sample sizes, and for analysis of genetic and epigenetic mechanisms that regulate gene expression during normal development and in diseased states, specifically pancreatic cancer. He is also funded to study factors involved in the regulation of bud dormancy in Vitis vinifera, and has interests in biodiversity and improvement of third-world agriculture. He has published more than 180 scholarly research articles, holds several patents, was elected a Fellow of the American Association for Advancement of Science in 2002, and serves on the editorial board of Cytometry Part A. He is widely sought as a speaker, having presented over 360 seminars in academic, industrial and conference settings. He was elected Secretary of the International Society for Advancement of Cytometry in 2016. Keywords: Plant and Animal Cellular Engineering; Biological Instrumentation; Flow Cytometry and Sorting

Publications

Galbraith, D. W., Janda, J., & Lambert, G. M. (2011). Multiparametric analysis, sorting, and transcriptional profiling of plant protoplasts and nuclei according to cell type.. Methods in molecular biology (Clifton, N.J.), 699, 407-429.

PMID: 21116995;Abstract:

Flow cytometry has been employed for the analysis of higher plants for approximately the last 30 years. For the angiosperms, ∼500,000 species, itself a daunting number, parametric measurements enabled through the use of flow cytometers started with basic descriptors of the individual cells and their contents, and have both inspired the development of novel cytometric methods that subsequently have been applied to organisms within other kingdoms of life, and adopted cytometric methods devised for other species, particularly mammals. Higher plants offer unique challenges in terms of flow cytometric analysis, notably the facts that their organs and tissues are complex three-dimensional assemblies of different cell types, and that their individual cells are, in general, larger than those of mammals.This chapter provides an overview of the general types of parametric measurement that have been applied to plants, and provides detailed methods for selected examples based on the plant model Arabidopsis thaliana. These illustrate the use of flow cytometry for the analysis of protoplasts and nuclear DNA contents (genome size and the cell cycle). These are further integrated with measurements focusing on specific cell types, based on transgenic expression of Fluorescent Proteins (FPs), and on analysis of the spectrum of transcripts found within protoplasts and nuclei. These measurements were chosen in particular to illustrate, respectively, the issues encountered in the flow analysis and sorting of large biological cells, typified by protoplasts; how to handle flow analyses under conditions that require processing of large numbers of samples in which the individual samples contain only a very small minority of objects of interest; and how to deal with exceptionally small amounts of RNA within the sorted samples.

Liwińska, E., Lambert, G. M., & Galbraith, D. W. (2002). Factors affecting nuclear dynamics and green fluorescent protein targeting to the nucleus in Arabidopsis thaliana roots. Plant Science, 163(3), 425-430.

Abstract:

Nuclear movement and targeting of a green fluorescent protein (GFP)-nuclear localization sequence (NLS)-β-glucuronidase (GUS) chimeric protein to the roots of transformed Arabidopsis has been studied using time lapse analysis. To characterize the mechanism governing this movement, metabolic inhibitors, and chemicals that alter the concentrations of divalent cations in the cell were applied. Flow cytometry was used to examine the condition of nuclear membranes. The results showed that nuclear movement in Arabidopsis roots was energy-dependent. The concentration of magnesium ions seemed to play a crucial role in the movement of the nuclei and targeting of the chimeric GFP protein into the nucleoplasm. In contrast, alterations in concentration of calcium ions did not affect either nuclear dynamics or nucleoplasmic GFP accumulation. The results are discussed in terms of some of the physiological processes occurring within the cell. © 2002 Elsevier Science Ireland Ltd. All rights reserved.

Galbraith, D., & Galbraith, D. W. (1994). Flow cytometry and sorting of plant protoplasts and cells. Methods in cell biology, 42 Pt B.
Galbraith, D., Janda, J., & Lambert, G. (2011). Multiparametric analysis, sorting, and transcriptional profiling of plant protoplasts and nuclei according to cell type. Methods in Molecular Biology, 699, 407-429.
Galbraith, D. W., Harkins, K. R., & Knapp, S. (1991). Systemic endopolyploidy in Arabidopsis thaliana. Plant Physiology, 96(3), 985-989.

PMID: 16668285;PMCID: PMC1080875;Abstract:

Microfluorometric analysis of the nuclear DNA contents of the somatic tissues of Arabidopsis thaliana has revealed extensive endoreduplication, resulting in tissues that comprise mixtures of polyploid cells. Endoreduplication was found in all tissues except those of the inflorescences and was developmentally regulated according to the age of the tissues and their position within the plant.