Plant Cell Biology Research Articles

When microspores decide to become embryos — cellular and molecular changesThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology.

Cultured microspores can be induced to develop into fully functional haploid embryos instead of mature pollen. The ability of these cells to change their development in response to environmental stimuli is an exceptional example of totipotency in plants. Discovering the triggers of embryo development in microspore cultures could lead to a greater understanding of the early stages of embryogenesis in plants and might be used to increase the range of crop plants to which microspore culture can be applied for the production of double haploid homozygous lines. The information might also help to define the general characteristics of pluripotent cells in any organism. In this review, the changes that occur in cellular organization and gene expression in early-stage microspore cultures of several species are discussed. Responding cells in these cultures enlarge, their nuclei are repositioned to their cell centres, and their cytoplasms become filled with fragmented vacuoles. We used flow cytometry to track cellular changes in canola ( Brassica napus L.) microspore cultures as well as microarray analyses and real-time PCR to compare gene expression in embryogenic and nonembryogenic cells. A model for embryogenic cell activation in plants that involves alkalinization, Ca2+ signaling, and changes in GTPase activity that lead to significant changes in gene expression is discussed.

Dr. Ottó Orsós, the forgotten Hungarian pioneer in plant tissue culture

The knowledge of tissue culture deserves attention in respect of understanding the development of universal biology. This study intends to contribute to the past of the plant tissue culture by such data of the history of science which have been unprocessed so far. It seems that the life-work of the Hungarian biologist, Dr. Ottó Orsós is a missing and essential link between those early plant hormone researchers and the representatives of the pioneers of tissue culture schools who have contributed substantially to the development of the modern in vitro plant morphogenesis and plant cell biology. Orsós cultured kohlrabi tuber cubes on White culture medium in a sterile manner. This way, he could efficiently direct the in vitro morphogenesis of the kohlrabi, the regeneration of its shoot and root, and the formation and steps to subculture of pure callus tissues in 1938. He supported the correctness of its statements by means of detailed anatomical examinations. Orsós successfully rooted and aclimatized complete regenerated plants. We may as well call the above system — in remembrance of the creators of the original concept — "Haberlandt-Orsós model". Between the publishing of his main paper in 1938 and 2003, a period of 65 years has lapsed. On the occasion of this anniversary, we bow before this forgotten pioneer.

Multiple shoots formation of an important tropical medicinal plant, Eurycoma Iongifolia Jack

Eurycoma longifolia Jack is well known among the communities in Southeast Asia because of its aphrodisiac properties and its effectiveness as the cytotoxic, anti-malarial, anti-ulcer, anti-tumor promoting and anti-parasitic agent. Micropropagation through direct plant regeneration from in vivo shoot tip explants was carried out. The highest regeneration percentage (90%) and multiple shoots formation were obtained with the basal Murashige and Skoog (MS) medium supplemented with 5.0 mg l-1 kinetin. Roots were induced after 14 days of culture in the basal MS medium supplemented with 0.5 mg l -1 of indole-3-butyric acid. Plantlets regenerated from shoot tip explants survived well with no morphological differences from parent plants after two months of transplantation to soil. Copyright © 2005 The Japanese Society for Plant Cell and Molecular Biology.

+TIPs and microtubule regulation. The beginning of the plus end in plants.

Plants have evolved novel microtubule (MT) arrays to regulate cell division and cell expansion. How these MT arrangements are managed has been a question of long-standing interest to plant cell biologists. Do plants have unique ways of regulating MTs or have they co-opted mechanisms that are

A new tool for plant cell biology: in vivo antibody uptake in plant protoplasts.

We report on the in vivo uptake of antibodies into plant protoplasts. When protoplasts of sunflower, Arabidopsis or tobacco were incubated in vivo with an antibody, this antibody was detected by immunofluorescence in the cytoplasm and/or the nucleus, depending on the location of the target protein. Furthermore, when protoplasts were cultured in the presence of antibodies, specific effects were observed. Incubation with antibodies raised against p34cdc2 led to a strong inhibition of the division rate, and a decrease in the average DNA content of protoplasts. With antibodies against HaWLIM1, a LIM domain protein of the CRP type, a negative effect on actin organisation was observed. We conclude that antibodies can penetrate plant protoplasts in vivo, and thus may be used as powerful tools for the study of protein function.

Where, oh where has my protein gone?

A recent publication by R. Chikwamba and colleagues highlights interesting issues in recombinant protein expression in transgenic plants. In the study they expressed a bacterial antigen in maize seed and obtained aberrant localization data. This work is of great importance to the biotechnology industry and raises fascinating questions in plant cell biology that require creative thinking.

Proteomic Analysis of Glycosylphosphatidylinositol-anchored Membrane Proteins

Glycosylphosphatidylinositol-anchored proteins (GPI-APs) are a functionally and structurally diverse family of post-translationally modified membrane proteins found mostly in the outer leaflet of the plasma membrane in a variety of eukaryotic cells. Although the general role of GPI-APs remains unclear, they have attracted attention because they act as enzymes and receptors in cell adhesion, differentiation, and host-pathogen interactions. GPI-APs may represent potential diagnostic and therapeutic targets in humans and are interesting in plant biotechnology because of their key role in root development. We here present a general mass spectrometry-based proteomic "shave-and-conquer" strategy that specifically targets GPI-APs. Using a combination of biochemical methods, mass spectrometry, and computational sequence analysis we identified six GPI-APs in a Homo sapiens lipid raft-enriched fraction and 44 GPI-APs in an Arabidopsis thaliana membrane preparation, representing the largest experimental dataset of GPI-anchored proteins to date.

Activation of cell proliferation by brassinolide application in tobacco BY-2 cells: effects of brassinolide on cell multiplication, cell-cycle-related gene expression, and organellar DNA contents.

Brassinosteroids (BRs) are steroidal phytohormones that are essential for many processes in plant growth and development, such as cell expansion, vascular differentiation, and responses to stress. The effects of BRs on cell division are unclear, as attested by contradictory published results. To determine the effect of BRs on cell division, the tobacco (Nicotiana tabacum) BY-2 cell line, which is a widely-used model system in plant cell biology, was used. It was found that brassinolide (BL) promoted cell division only during the early phase of culture and in the absence of auxin (2,4-D). This promotion of cell division was confirmed by RNA gel blot analyses using cell-cycle-related gene probes. At later stages in the culturing periods of BL-supplied and 2,4-D-supplied BY-2 cells, differences in cell multiplication and cell-cycle-related gene expression were observed. Moreover, the BL-treated BY-2 cells had morphological differences from the 2,4-D-treated cells. To determine whether suppressed organellar DNA replication limited this promotion of cell division during the early culture phase, this replication was examined and it was found that BL treatment had no effect on activating organellar (plastid- and mitochondrial-) DNA synthesis. As preferential organellar DNA synthesis, which is activated by 2,4-D, is necessary during successive cell divisions in BY-2 cells, these data suggest that the mechanism of the promotion of cell division by BL treatment is distinct from that regulated by the balance of auxin and cytokinin.

Efficient regeneration from cotyledon protoplasts in Arabidopsis thaliana

An efficient and fast regeneration system from cotyledon protoplasts was established for Arabidopsis thaliana accessions C24, Columbia, and Wassilewskija. Culture conditions and media compositions were optimised for the development of protoplasts embedded in thin alginate layers. Unexpectedly, the absence of cytokinins had a positive effect on cell development. Moreover, combined adjustment of alpha-naphthylacetic acid and dicamba concentrations resulted in high plating efficiencies of up to 30%, followed by shoot regeneration within only 19 days after protoplast isolation. The protocol is reproducible, efficient, extremely fast, and regenerated plants are fertile. Thus, this cotyledon-based system could prove useful for studying plant cell and molecular biology in A. thaliana.

Virtual environments in biology teaching

This article reports on the design, development and evaluation of an educational virtual environment for biology teaching. In particular it proposes a highly interactive three-dimensional synthetic environment involving certain learning tasks for the support of teaching plant cell biology and the process of photosynthesis. The environment has been evaluated using a sample of 37 in-service teachers. Their attitudes towards virtual reality for educational use were positive. Almost all the teachers managed to integrate the process of photosynthesis inside the virtual cell and answer the relevant questions. One problem was that the teachers were unable to answer questions beyond the certain learning tasks, indicating that any educational software should also involve an integrated approach to the subject under study.

Scanning Electron Microscopy of Leaves of Southern Live Oak

Yadong Qi* and Ying Xiao** *Urban Forestry Program, Southern University and A&M College, Baton Rouge LA 70813 **Department of Biology, Louisiana State University, Baton Rouge LA 70803 Southern live oak (Quercus virginiana Mill.) is a large evergreen broadleaf tree species that has significant landscape values in the U.S. This species is considered a virtual emblem of the Old South. Very little information is available regarding the leaf anatomy of the tree. This paper presents the scanning electron microscopy (SEM) of leaf gross morphology and anatomical features of live oak. The information will contribute to our better understanding of the physiology and morphology, tree growth and development of this species. Sun-exposed leaves were collected from mature southern live oak trees on Southern University campus in the end of June. Leaves were prepared for scanning electron microscopy. They were dissected, fixed in FAA (Ethanol, Glacial Acetic Acid, and Formaldehyde), dehydrated in an ethanol series, and dried in carbon dioxide using Denton DCP-1 critical point drying apparatus. Leaves were mounted on stubs, coated with 25 nm gold palladium using a Hummer II Sputter Coater, and examined using a Cambridge S-260 scanning electron microscope. The scanning electron micrographs of southern live oak leaves are illustrated in FIG. 1. The abaxial surfaces of the leaves are covered with a thick layer of trichome with multicellular peltate (shield-shaped) structure (FIG. 1a). A secretory function has been attributed to this type of leaf hairs [1]. A fully developed individual trichome shows as many as seventeen long narrow cells that are fused together for nearly half of their length. The surfaces of the trichome cells form a distinctive type of cuticle morphology, in which the outer surface is thrown into warty projections (FIG. 1b), indicating reinforced cell walls. This type of cuticle reinforcement was also reported in the leaf hairs of goosegrass (Galium aparine) [2]. The stomata are only presented on the abaxial surface and are generally covered up by the trichome. On the top of the guard cells around the stomatal aperture is cuticle serving as a primary protective layer in addition to the trichome layer (FIG. 1c). The adaxial leaf surface morphology is significantly different from the abaxial surface (FIG. 1d). The adaxial surfaces have no trichome at all and are smoothly covered by the cuticle and wax. The leaf transverse structure shows that the palisade tissue consists of three layers of compacted parenchyma cells (FIG. 1e). The thick trichome layer and closely packed palisade tissues are significant features of southern live oak leaves. The trichome layer functions as a mechanical barrier against biotic attack, an additional resistance to the diffusion of water vapor from leaf interior to the atmosphere, a reflector reducing the radiant energy absorbed by the leaf, and an absorber to help screen out harmful UV-B radiation from the sun. The closely packed palisade cells enhance photosynthesis efficiency by increasing photosynthetic sites and surface area of leaf interior. Thus, these leaf anatomical features provide southern live oak with specific eco-physiological advantages. Reference [1] J.H. Troughton and F.B. Sampson, Plants, John Wiley & Sons Australasia Pty Ltd, 1973. [2] B.S. Gunning and M.W.Steer, Plant Cell Biology Jones and Bartlett Publishers, 1996.

Frontiers of plant cell biology: signals and pathways, system-based approaches 22nd Symposium in Plant Biology (University of California--Riverside).

The symposium ''Frontiers of Plant Cell Biology: Signals and Pathways, Systems-Based Approaches'' was held January 15-18, 2003 at the Riverside Convention Center in Riverside, California. The host organization for the symposium was the Center for Plant Cell Biology (CEPCEB) at the University of California, Riverside (UCR). The meeting, focusing on systems-based approaches to plant cell biology research, was the first of this kind in the field of plant biology. The speakers and nearly 100 posters placed emphasis on recent developments in plant cellular biology and molecular genetics, particularly those employing emerging genomic tools, thereby sharing the most current knowledge in the field and stimulating future advances. In attendance were many well-established scientists and young investigators who approach plant cell biology from different but complementary conceptual and technical perspectives. Indeed, many disciplines are converging in the field of cell biology, producing synergies that will enable plant scientists to determine the function of gene products in the context of living cells in whole organisms. New, cross-disciplinary collaborations, as well as the involvement of computer scientists and chemists in plant biology research, are likely additional outcomes of the symposium. The program included 39 invited session speakers and workshop/panel speakers. Sessions were convened on the following themes: Cell-Cell Communication; Protein Trafficking; Cell Surface, Extracellular Matrix and Cell Wall; Signal Transduction; Signal Transduction and Proteosome; and Systems-Based Approaches to Plant Cell Biology. Workshops on Chemical Genetics and Visual Microscopy were also presented. Abstracts from each of the speaker presentations, as well as the posters presented at the meeting were published in a program booklet given to the 239 faculty members, researchers, postdoctoral scientists and graduate students in attendance. The booklet thus serves as a reference for symposium attendees to locate additional information about a topic of their particular interest and to contact other investigators. In addition, an article reviewing the symposium by science writer Peter V. Minorsky appeared in the June 2003 issue of Plant Physiology, a special issue devoted to systems-based approaches in the study of the model plant Arabidopsis (article submitted as part of this Final Technical Report).

Modifying plant growth and development using the CDK inhibitor ICK1.

Cell Biology InternationalVolume 27, Issue 3 p. 297-299 Modifying plant growth and development using the CDK inhibitor ICK1 H. Wang, H. Wang Department of Biochemistry, University of Saskatchewan, Saskatoon SK, Canada S7N 5E5 Saskatoon Research Centre, AAFC, Saskatoon SK, Canada S7N 0X2Search for more papers by this authorY. Zhou, Y. Zhou Saskatoon Research Centre, AAFC, Saskatoon SK, Canada S7N 0X2 Department of Biology, University of Saskatchewan, Saskatoon SK, Canada S7N 5E2Search for more papers by this authorS. Gilmer, S. Gilmer Department of Biology, University of Saskatchewan, Saskatoon SK, Canada S7N 5E2Search for more papers by this authorA. Cleary, A. Cleary Plant Cell Biology, Australian National University, Canberra, AustraliaSearch for more papers by this authorP. John, P. John Plant Cell Biology, Australian National University, Canberra, AustraliaSearch for more papers by this authorS. Whitwill, S. Whitwill Saskatoon Research Centre, AAFC, Saskatoon SK, Canada S7N 0X2Search for more papers by this authorL. Fowke, Corresponding Author L. Fowke Department of Biology, University of Saskatchewan, Saskatoon SK, Canada S7N 5E2Corresponding author. Tel.: +1-306-966-4402; fax: +1-306-966-4461. [email protected]Search for more papers by this author H. Wang, H. Wang Department of Biochemistry, University of Saskatchewan, Saskatoon SK, Canada S7N 5E5 Saskatoon Research Centre, AAFC, Saskatoon SK, Canada S7N 0X2Search for more papers by this authorY. Zhou, Y. Zhou Saskatoon Research Centre, AAFC, Saskatoon SK, Canada S7N 0X2 Department of Biology, University of Saskatchewan, Saskatoon SK, Canada S7N 5E2Search for more papers by this authorS. Gilmer, S. Gilmer Department of Biology, University of Saskatchewan, Saskatoon SK, Canada S7N 5E2Search for more papers by this authorA. Cleary, A. Cleary Plant Cell Biology, Australian National University, Canberra, AustraliaSearch for more papers by this authorP. John, P. John Plant Cell Biology, Australian National University, Canberra, AustraliaSearch for more papers by this authorS. Whitwill, S. Whitwill Saskatoon Research Centre, AAFC, Saskatoon SK, Canada S7N 0X2Search for more papers by this authorL. Fowke, Corresponding Author L. Fowke Department of Biology, University of Saskatchewan, Saskatoon SK, Canada S7N 5E2Corresponding author. Tel.: +1-306-966-4402; fax: +1-306-966-4461. [email protected]Search for more papers by this author First published: 02 January 2013 https://doi.org/10.1016/S1065-6995(02)00310-4Citations: 6AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume27, Issue3March 2003Pages 297-299 RelatedInformation

Robert Brown. 29 July 1908 – 13 July 1999

It was Robert Brown who brought botany into the mainstream of developmental biology, integrating plant physiology, cell biology, biochemistry and molecular biology into a holistic view of plant growth. Robert's scientific legacy is not just what he himself accomplished but also what he inspired others to do.

Chlamydomonas Chloroplast Genome and Transcriptome Analysis

Chlamydomonas reinhardtii is a unicellular green alga that is widely used as a model system in the study of photosynthesis and other aspects of cell biology. This issue of The Plant Cell includes two reports on Chlamydomonas genomics that represent important landmarks in plant cell biology ([Figure

Plant gametes as tools for molecular breeding

Sexual reproduction plays an essential role in the propagation of Angiosperms. Fertilisation takes place in the embryo sac, which is usually deeply encased in the sporophytic tissues of the ovule. In contrast to animals and primitive plants, the mechanism of egg cell activation in flowering plants has not been discovered fully because of the inaccessibility and complexity of the process of double fertilisation. However, recent advances in plant cell and molecular biology have brought new, powerful technologies to investigate and micromanipulate the reproductive cells of flowering plants including cereal crops. An experimental approach based on various micromanipulation techniques involving in vitro fertilisation (IVF) and microinjection procedures is now available in more and more laboratories. Despite some limitations this offers new possibilities to study cellular and subcellular events preceding or occurring during or after egg cell activation and early embryonic development. Recent achievements in the field of wheat egg cell micromanipulation are presented in this paper.

Introduction

This is an auspicious time for plant cell biology. We have the recent genome sequence of the model plant Arabidopsis, together with powerful new sets of tools that include functional genomics and the dynamic imaging of green fluorescent protein (GFP)–conjugated proteins by confocal microscopy. We are well placed indeed for uncovering the ways in which all genes act out their roles within individual cells. It is the combinatorial properties of these individual cells that underpin both the higherorder processes of plant growth and development and of plant evolution. At a crucial level in the hierarchy of explanations and structures, between the linear DNA sequence at one extreme and whole plant phenomena at the other, lies the cell. It is to this cellular level, to the irreducible unit of life, that this collection of papers is addressed, literally ‘between genome and plant’. Most of the major conceptual advances in our understanding of cell biology have come from work with animal and fungal systems. The ways in which membranes create dynamic compartments within cells and the role of the cytoskeleton in providing an ordering framework are familiar from the textbooks. But plant cells have special features.

Protocols for plant cell biologists

Plant cell biology (2nd edition) Edited by C. R. Hawes & B. Satiat-Jeunemaitre. 338 pages. Oxford, UK: Oxford University Press, 2001. £70.00 hours/b. ISBN 0 19 963866 7 In Plant cell biology (2nd edition) a practical approach, an attempt has been made to do the impossible. Editors Chris Hawes and Béatrice Satiat-Jeunemaitre have attempted to collect into a single, reasonably priced volume descriptions of, and protocols for, most of the techniques used by plant cell biologists. A wide range of methodologies are presented, including light and electron microscopy, immunocytochemistry and in situ hybridization, transient expression of genes in plant cells, and use of the green fluorescent protein (GFP) as a reporter molecule. Each chapter is written by researchers who share with the reader insights that have come from their own experience, and protocols from their own laboratories. The editors, perhaps deliberately, have done little to impose a uniform writing style. Although this is slightly off putting when liberties are taken with standard English, it reinforces the impression that what is presented is based on the experience of individuals and on the success they have had with particular cell types, tissues and plant species. Of note are excellent, thorough chapters on optical microscopy, fluorescent probes for live cells, in situ hybridization, and organelle isolation. The chapter ‘Plant histology’ provides a brief introduction to the subject, and will be useful to those needing a set of standard protocols. There is a wealth of information in the chapter ‘Electron microscopy’, though at times the inclusion of so much material obscures the organization of the chapter and is confusing. Likewise ‘Immunocytochemistry for light microscopy’ lacks the focus that would make it most useful to novices. Coverage of transient expression seems, at first glance, to be extremely limited since only electroporation is described in any detail. Fortunately, protocols for plant transformation using polyethylene glycol, Agrobacterium, Potato Virus X and biolistics are included in the chapter ‘The green fluorescent protein (GFP) as reporter in plant cells’. The chapter on microinjection scarcely mentions transformation via microinjection, but does discuss in detail the unique challenges posed by various cell types. Perhaps least useful to most readers, except as a description of the methodology, is ‘Micromanipulation by laser microbeams and optical tweezers’. The chapter on electrophysiological methods, surprisingly, is restricted to capacitance measurements as an assay for exo- and endocytosis. More basic voltage clamp and patch clamp techniques have been extremely useful tools for plant cell biologists during the past two decades. It is unfortunate that explicit protocols were not included for making measurements of, for example, voltage difference across the plasma membrane or whole cell currents. Flow cytometry is a powerful technique that is rarely used by plant biologists, but commonly used by other cell biologists. It is disappointing therefore that the chapter on flow cytometry covers only the quantification of DNA in nuclei in any depth. Illustrating a wider range of applications would have been beneficial to the plant science community. This book will be an excellent resource for anyone who needs more than a cursory introduction to an unfamiliar methodology. Those that will find it useful are scientists who want to use a new technique for their own research, and instructors trying to develop contemporary laboratory exercises. Plant cell biology (2nd edition) a practical approach, does not accomplish the impossible. Yet it is a remarkably good attempt, and exceptionally good value. I highly recommend it.

The role of biotechnologies in the development of sunflower cultures in the world

SUMMARY Sunflower improvement by conventional breeding is severely restricted by the availability of a rather limited gene pool owing to natural incompatibilities, even between related species, and by the time scale of most breeding programs. Therefore, much attention has been directed recently to the newly emerging and novel technologies of plant cell and molecular biology that provide a powerful means to supplement and complement the traditional methods of plant improvement. The concept of DNA-based markers has revolutionized our ability to directly access any part of the plant genome, and has led to new opportunities such as map-based cloning and directed plant breeding. Efficient regeneration of fertile plants from cultured cells and protoplats, combined with novel methods of DNA delivery and selection of transformed cells, has resulted in the production of transgenic sunflower. Agronomically useful genes, which confer resistance to insect pests and pathogens, have been introduced. However, further molecular improvement of sunflower could be limited most by the lack of our knowledge about, and access to, important and useful genes (e.g., those controlling multigenic traits like yield, and resistance to biotic and abiotic stresses). Therefore, high priority should be given to the development of ultra high density (UHD) linkage maps and the development of new tools for high-throughput genome and expression analyses.

Classification, expression pattern and comparative analysis of sugarcane expressed sequences tags (ESTs) encoding glycine-rich proteins (GRPs)

Since the isolation of the first glycine-rich proteins (GRPs) in plants a wealth of new GRPs have been identified. The highly specific but diverse expression pattern of grp genes, taken together with the distinct sub-cellular localization of some GRP groups, clearly indicate that these proteins are involved in several independent physiological processes. Notwithstanding the absence of a clear definition of the role of GRPs in plant cells, studies conducted with these proteins have provided new and interesting insights into the molecular biology and cell biology of plants. Complexly regulated promoters and distinct mechanisms for the regulation of gene expression have been demonstrated and new protein targeting pathways, as well as the exportation of GRPs from different cell types have been discovered. These data show that GRPs can be useful as markers and/or models to understand distinct aspects of plant biology. In this paper, the structural and functional features of these proteins in sugarcane (Saccharum officinarum L.) are summarized. Since this is the first description of GRPs in sugarcane, special emphasis has been given to the expression pattern of these GRP genes by studying their abundance and prevalence in the different cDNA-libraries of the Sugarcane Expressed Sequence Tag (SUCEST) project . The comparison of sugarcane GRPs with GRPs from other species is also discussed.