Nitric Oxide and Signaling in Plants

A resynthesis or re-extraction?: Plant Biochemistry and Molecular Biology (2nd edition), edited by Peter J. Lea and Richard C. Leegood

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.

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

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.

Visualizing plant cell biology

Handbook of Plant Science

The sixth in a series of authoritative reviews of current progress in plant molecular and cell biology. Each volume contains papers on topics in areas of molecular genetics, biochemical and cell genetics, plant micro-organism interactions, and cell biology. The reviews are concentrated on areas of rapid development particularly where modern techniques are allowing new insights to be gained. In order to cope with the pace of research in this active area, the reviews are published within four to six months of their completion.

Arabidopsis root is a classic model system in plant cell and molecular biology. The sensitivity of plant roots to local environmental perturbation challenges data reproducibility and incentivizes further optimization of imaging and phenotyping tools. Here we present RoPod, an easy-to-use toolkit for low-stress live time-lapse imaging of Arabidopsis roots. RoPod comprises a dedicated protocol for plant cultivation and a customizable 3D-printed vessel with integrated microscopy-grade glass that serves simultaneously as a growth and imaging chamber. RoPod reduces impact of sample handling, preserves live samples for prolonged imaging sessions, and facilitates application of treatments during image acquisition. We describe a protocol for RoPods fabrication and provide illustrative application pipelines for monitoring root hair growth and autophagic activity. Furthermore, we showcase how the use of RoPods advanced our understanding of plant autophagy, a major catabolic pathway and a key player in plant fitness. Specifically, we obtained fine time resolution for autophagy response to commonly used chemical modulators of the pathway and revealed previously overlooked cell type-specific changes in the autophagy response. These results will aid a deeper understanding of the physiological role of autophagy and provide valuable guidelines for choosing sampling time during end-point assays currently employed in plant autophagy research.

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.

JIPB in 2010 – A More Reader‐Friendly International Journal

One of the current mantras in research publishing is that science papers should ‘‘tell a story.’’ I have been known to utter this phrase to my own trainees in the form of a strong suggestion. Current wisdom states that telling a cogent story through a scientific publication is an important vehicle to render research findings understandable—not only to reviewers and primary readers of the papers, i.e., other scientists, but also to science writers and the public. After all, a paper with a novel finding that tells a good story can potentially get published in a journal with a high impact factor and will be cited at high frequency. And if these conventional research metrics are not enough to spur on the storytelling, we are now reminded of ‘‘altmetrics’’ (see http://altmetrics.org/manifesto) such as the number of posts on blogs, Facebook and popular media articles. Of course, one problem about telling a story is that stories, by their nature, are often fictional. Research journal articles fall into the genre of non-fiction. The temptation to embellish or ‘‘tell a tall tale,’’ ever-present in the quest of storytelling, cannot be tolerated in science papers. ‘‘A picture is worth a thousand words’’ goes the old saying. Historically, illustrations, graphs, micrographs and other types of figures in papers were used to show key data that would help the reader to understand the most important findings in a study. The same is true today, but in the digital age, molecular data in gels, blots and photographic images are easily manipulated with a few mouse swipes and keystrokes. In addition, raw data images included in older techniques, such as northern blot analysis has been replaced by real-time RT-PCR summary data. Papers published in Plant Cell Reports are typically awash with digital data and images, which should give us pause for a reality check. Back in the old analog days of Kodachrome and Polaroids, what you saw was truth—the raw data. The common adage, ‘‘typical results are shown’’ was usually interpreted as ‘‘best results are shown,’’ but at least the reader could assume that the results were real, and that they were, to some degree, represented by the image. Sadly, programs such as Photoshop render this assumption obsolete. Readers, reviewers and editors should be vigilant to assess if ‘‘typical results’’ are actual results at all. Fanelli’s (2009) meta-analysis of research misconduct surveys found that 1.97 % of scientists admitted to falsification or fabrication. More shocking is that scientists admitted that they had observed that 14.12 % of their colleagues had falsified research (Fanelli 2009). Estimates range as high as 20 % of cell biology papers containing a questionable figure (Pearson 2005). Rossner and Yamada (2004) have succinctly described guidelines about permissible image manipulation. There is no need to recapitulate the details of their discussion here—I encourage all scientists to read their paper. What is important as an overriding research integrity issue is that the images shown on the pages of Plant Cell Reports and other journals should reflect the true nature of the data and the experiments performed. For example, if a gel contained 12 lanes, then the best practice is to show the entire gel and only the gel in the panel—the unit of the study should be made clear to the reader. Therefore, images of separate gels should not be spliced together, and if lanes within a gel are removed in an image, it is best practice to state the image was manipulated. A photographic image of plant cells or tissues should be honestly representative. A key guideline is that Communicated by G. Hahne.

The use of geminiviruses in biotechnology and plant molecular biology, with particular focus on Mastreviruses

A JOURNEY THROUGH PLANT CYTOSKELETON: HOT SPOTS IN SIGNALING AND FUNCTIONING.

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

Preface