Visualizing plant cell biology

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.

Cell polarity reflected by asymmetric distribution of proteins at the plasma membrane is a fundamental feature of unicellular and multicellular organisms. It remains conceptually unclear how cell polarity is kept in cell wall-encapsulated plant cells. We have used super-resolution and semi-quantitative live-cell imaging in combination with pharmacological, genetic, and computational approaches to reveal insights into the mechanism of cell polarity maintenance in Arabidopsis thaliana. We show that polar-competent PIN transporters for the phytohormone auxin are delivered to the center of polar domains by super-polar recycling. Within the plasma membrane, PINs are recruited into non-mobile membrane clusters and their lateral diffusion is dramatically reduced, which ensures longer polar retention. At the circumventing edges of the polar domain, spatially defined internalization of escaped cargos occurs by clathrin-dependent endocytosis. Computer simulations confirm that the combination of these processes provides a robust mechanism for polarity maintenance in plant cells. Moreover, our study suggests that the regulation of lateral diffusion and spatially defined endocytosis, but not super-polar exocytosis have primary importance for PIN polarity maintenance.

Introduction to a Virtual Special Issue on cell biology at the plant-microbe interface.

Plant cell biologists are often perceived as the guys that produce esthetically appealing images, and are deeply rooted in the realm of pure science, far away from anything that might be biotechnologically relevant. Why should the taxpayer fund this curiosity-driven type of research? Maybe, because science is a central part of human culture and therefore should be supported in the same manner as the public funds theatres or art exhibitions? This view is frequently encountered in the West. If this view were true, why should a pragmatic country like China invest so much effort to develop plant cell biology—by the way manifested by a rising number of cell-biological publications from China also in this journal. These considerations motivated an exploratory symposium on “Applied Plant Cell Biology” in March 2011 funded by the SinoGerman Science Center, where 40 scientists from both countries highlighted different aspects of the interface between plant cell biology and application. The pronounced developmental and metabolic capacities of plant cells provide the base of agriculture and green biotechnology and have been studied very intensively with respect to its genetic aspects. The so-called Green Revolution has ensured a reliable and cost-efficient supply with food resources to a growing population. A major part of this success story is based on three factors: advances in plant nutrition, advances in plant protection, and advances in plant genetics. The challenge of the coming years will be to reconcile increased agricultural productivity with sustainability. The potential of plant nutrition and plant protection has been basically exploited, what remains, are advances in generating new genotypes with improved productivity, tolerance to biotic and abiotic stresses, and improved or even novel metabolic potential. However, it becomes increasingly clear that the potential of applied plant science can only be fully exploited when we understand the cellular mechanisms such as compartmentalisation, intracellular transport, cell differentiation, and communication. To understand biotechnologically relevant molecular mechanisms for stress tolerance and accumulation of interesting compounds, we need a strong background in molecular cell biology. Therefore the current special issue exemplarily has selected three issues from this symposium highly relevant for biotechnological application: control of plant architecture through cytoskeleton and cell wall, control of development by signals, and the impact of cellular compartmentalisation for plant metabolism.

Stresses increasing the load of unfolded proteins that enter the endoplasmic reticulum (ER) trigger a protective response termed the unfolded protein response (UPR). Stromal cell-derived factor2 (SDF2)-type proteins are highly conserved throughout the plant and animal kingdoms. In this study we have characterized AtSDF2 as crucial component of the UPR in Arabidopsis thaliana. Using a combination of biochemical and cell biological methods, we demonstrate that SDF2 is induced in response to ER stress conditions causing the accumulation of unfolded proteins. Transgenic reporter plants confirmed induction of SDF2 during ER stress. Under normal growth conditions SDF2 is highly expressed in fast growing, differentiating cells and meristematic tissues. The increased production of SDF2 due to ER stress and in tissues that require enhanced protein biosynthesis and secretion, and its association with the ER membrane qualifies SDF2 as a downstream target of the UPR. Determination of the SDF2 three-dimensional crystal structure at 1.95 A resolution revealed the typical beta-trefoil fold with potential carbohydrate binding sites. Hence, SDF2 might be involved in the quality control of glycoproteins. Arabidopsis sdf2 mutants display strong defects and morphological phenotypes during seedling development specifically under ER stress conditions, thus establishing that SDF2-type proteins play a key role in the UPR.

Cytokinesis in plant and animal cells: Endosomes ‘shut the door’

Of all the discoveries in plant cell biology over the past two decades, uncovering the role of Ca2+ has probably been the most dramatic. Twenty years ago Ca2+ was assigned, along with other minerals, to the role of nutrient, a simplistic view which has altogether proved inappropriate. Calcium was thought of as primarily a structural component of the cell wall and therefore about as interesting as bone. Today we know that Ca2+ stands at the heart of life itself. Many of the spatial and dynamic characters of cell polarity, directed secretion, cell-cycle progression, cell development, and the sensing of light, gravity, or touch ultimately depend upon the unusual properties that Ca2+ possesses in cells. The old quotation from Loewi—‘Ja calcium, das ist alles’ (calcium is everything)—is reasonably accurate. Calcium is the most dynamic of signalling molecules and living systems have fashioned an exquisite hierarchy of signalling capabilities around it.

The plant endoplasmic reticulum (ER) is a dynamic organelle composed of multiple distinct structural domains, such as cisternae, which are maintained by ER morphogens including the Arabidopsis thaliana Lunapark proteins (LNPs). Cisternae are typically described as sac-like structures connected by tubules. Here we challenge this assumption and propose that cisternae have a more complex structure that modifies ER functionality. This study used state-of-the-art high-resolution confocal and variable-angle epifluorescence microscopy, along with transmission electron microscopy and tomography, on high-pressure frozen Arabidopsis thaliana samples. We found that AtLNP1-stabilised ER forms cisternae composed of dense tubular matrices, whereas AtLNP2 forms cisternae with a uniform, sac-like structure. Furthermore, overexpression of AtLNP proteins alters Golgi morphology, affecting ER-to-Golgi transport and secretion. Our findings reveal that the balance between AtLNP1 and AtLNP2 is critical for ER cisternae organisation and ER functionality in protein production and secretion. This work provides new insights into ER structural plasticity and its functional implications in plant cells.

The year 2018 marks the 165th birthday of Journal of Cell Science. The journal has seen many substantial changes since its inception, including the change of name in 1965 from the somewhat laborious ‘Quarterly Journal of Microscopical Science’ to ‘Journal of Cell Science’. Over the past year alone, we have introduced a number of changes that were designed to strengthen our ties with early-career researchers and improve the experience for our readers and authors. In addition to our popular Cell Scientists to Watch series, in which we interview talented researchers who have recently set up their own labs, we now also feature ‘First Person’ interviews with the first author(s) of a selection of papers in each issue.In January 2017, together with Guest Editor Andrew Ewald, we published a special issue focused on ‘3D Cell Biology’. Following on from its success, we will be publishing a special issue each year. Look out for our ‘Plant Cell Biology’ special issue in January of this year, guest edited by Jenny Russinova. There is also still time to submit a paper to our ‘Reconstituting Cell Biology’ special issue, guest edited by Manuel Théry. The closing date for submissions is February 15th.In spring, we introduced ‘format-free’ submission as part of our commitment to make submission as easy as possible for authors. You can submit your manuscript for assessment in any format and, as part of this change, we removed the Materials and Methods from our article length limit because we don't want to limit the transparency and reproducibility that comes from having a comprehensive Materials and Methods section.May 2017 heralded the first Journal of Cell Science Meeting. Editor-in-Chief Michael Way, together with Editorial Advisory Board members Elizabeth Chen and Margaret Gardel, and Handling Editor Jennifer Lippincott-Schwartz, organised ‘Cellular dynamics: membrane-cytoskeleton interface’ in Southbridge, MA. Bringing together a diverse group of researchers for 3 days of intense and stimulating talks, the overwhelming response was that we need to do it again. We therefore invite you to apply for a place at ‘Cellular dynamics: organelle-cytoskeleton interface’, being held May 19-22, 2019 at the Pestana Palace Hotel in Lisbon. Organisers Michael Way, Edgar Gomes, Heidi McBride and Sharon Tooze promise an excellent line-up of speakers in a beautiful location – keep an eye out for further announcements.Many of our changes have been made specifically with our authors and readers in mind, and often follow on from feedback we receive. In response to many queries, for example, Journal of Cell Science now offers expedited ‘fast-track’ decisions (within a week) for previously reviewed manuscripts that are submitted with reports. We also expanded our ‘Tools and Techniques’ section to become ‘Tools and Resources’ after many of you enquired about resource-type manuscripts.In deciding where next to focus, we noted the community's growing interest in preprints, and so will have an exciting announcement in this regard in early February. We also surveyed the community, and found that the top priority was speed to publication. Although we do already post accepted manuscripts online shortly after acceptance, we decided that we could offer an even better service to authors and readers by ensuring that the best and final version of an article is available online as soon as possible. We have therefore moved to a continuous publication model. What this means is that we will build issues over a 2-week period with articles published as soon as they are ready instead of waiting for the final corrected proofs of all accepted articles before publishing an issue. For more information on continuous publication, please see our FAQs page (http://jcs.biologists.org/content/continuous-publication-faqs). A further benefit for readers is that we can offer more flexible alerting, with daily, weekly and issue-close updates available. Alert preferences can be updated at http://jcs.biologists.org/alerts.It is also important to note that the European Union has introduced the General Data Protection Regulation (GDPR; see http://www.biologists.com/what-is-gdpr/ for more details), so to ensure that you continue to hear about our journal meetings, special issues, calls for papers and other journal news, we would encourage you to sign up for news alerts at http://www.biologists.com/subscribe.We hope that 2018 is a happy and successful year for all of our authors and readers. This year brings many new changes for Journal of Cell Science, but some things will remain as they are, such as our commitment to not charge authors to publish with us. We also always welcome all feedback on our initiatives, so please do get in touch at any time at jcs@biologists.com and have your say in setting our direction for the coming years.

Nitric Oxide and Signaling in Plants

What a wonderful time this is for plant cell biology! Never before has a wealth of tools been adopted and adapted to dissect the molecular mechanisms underlying the functions of the plant cell. Genome sequencing, subcellular proteomics, and advanced imaging are just some of the astounding array of technologies that hold the promise to revolutionize the way we can study and appreciate plant cells. In a nutshell, this is what this Special Issue of Plant Cell Reports on ‘Organelle Biogenesis and Communication in Plant Cell’—the first of its kind for this journal—aims to bring to light in a unique collection of reviews and research articles. With no doubt, recent advances in organelle purification and proteomics coupled with entire genome sequencing are yielding important discoveries on species evolution as highlighted by Jo et al. (2011) and Lang et al. (2011), and advanced microscopy is allowing for the visualization and tracking of previously unknown aspects of organelle dynamics at a subcellular level in intact tissues, such as the regulation of mitochondrial morphology and motility in embryos presented by Yamaoka et al. (2011). Indeed, it is now possible to understand how organelles are implicated in more general aspects of plant biology, including cytoplasmic male sterility, as discussed by Matsunaga et al. (2011), nitrogen assimilation, as reviewed by Hakiya et al. (2011), and the regulation of developmental pathways, which, as reviewed by Merkle (2011), can be controlled through the nucleo-cytoplasmic transport of their signaling components. Finally, there have also been unprecedented advances in our understanding of the role of lipids and proteins in organelle membrane assembly, aspects of which are reviewed by Melser et al. (2011) and Abell and Mullen (2011). Taken together, the reviews and articles in this Special Issue of Plant Cell Reports summarize some of the stateof-the-art research in the field of plant cell biology and how our view of the cell is being constantly challenged as new information is acquired. However, this is only a facet of plant cell biology and the reader is encouraged to examine future issues of Plant Cell Reports for further examples of research that highlight this exciting field. We are indebted to all of the contributing authors for their thoughtprovoking reviews and research articles and to those colleagues that acted as reviewers.

Handbook of Plant Science

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

The quest for four-dimensional imaging in plant cell biology: it's just a matter of time.

Traffic between the plant endoplasmic reticulum and Golgi apparatus: to the Golgi and beyond