Ivan Radin

While the epidermis is a continuous layer, the leaf's uneven surface and differences in cell expression levels give it the appearance of multiple layers.
This stitched image (multiple fields of view merged together) was captured on an FV3000 confocal microscope from Evident/Olympus.

Fluorescent microscope image showing a dense network of bright green, irregularly shaped plant cells with glowing outlines against a dark background.

Surface (epidermal) cells of many plants are shaped like jigsaw puzzle pieces. 🧩
These are epidermal cells of tobacco (Nicotiana benthamiana) expressing cytosolic EGFP. The bright spherical structures are cell nuclei.
#microscopymonday, #plantcells, #plantmicroscopy

Promotional image for the PCA Imaging Workshop Webinar Series: Introduction to 2D and 3D Segmentation with MorphoGraphX. The promo has a purple background behind text over a green plant cell graphic with a black background. It also includes the details for the webinar including the date/time.

Promotional image for the PCA Imaging Workshop Webinar Series: Introduction to 2D and 3D Segmentation with MorphoGraphX. The promo has a purple background behind text over a green plant cell graphic with a black background. It also includes the webinar's full abstract description.

Registration is NOW OPEN for the second installment of the Plant Cell Atlas Imaging Workshop Series: Introduction to 2D and 3D Segmentation with MorphoGraphX.

You can learn more and register here: www.plantcellatlas.org/events

That's a great question. Unfortunately, we didn't continue imaging these samples, so I don't know.

I am not sure, but it would be cool. I will need to look into that.

Red fluorescence microscopy image showing a dense, mottled red signal across the field with a distinct dark, square-shaped region at the center where fluorescence is absent or reduced; a 100 µm scale bar appears in the lower-right corner.

We were testing lasers and the spectral ability of our confocal (FV3000) on a zoomed-in section of a Brassica rapa leaf. But when we zoomed out, we saw that the lasers we used photobleached chlorophyll autofluorescence in the square area we had zoomed in on. We used a 10x/0.4 objective for this.

Image shows a gray-scale image of many circular-shaped yeast cells. There are also many streaks caused by fast-moving cells.

These Brewer's yeast cells were in a hurry!
This was captured with a point-scanning confocal microscope, which scans one point (pixel) at a time, moving from left to right and top to bottom. As a consequence, cells moving faster than the scan speed appear as streaks or exhibit distortions.

Featured image with Ivan Radin - FocalPlane Featured image with Ivan Radin - News

Our featured image shows epidermal cells of a tobacco leaf expressing cytosolic GFP. The image was acquired by Ivan Radin @radinbio.bsky.social.
You can read more about the image and Ivan’s research in our post ⤵️
focalplane.biologists.com/2026/01/16/f...
#FluorescenceFriday

Bryophytes are not early diverging land plants Phylogenetic trees have permeated biology. However, an understanding of how to interpret phylogenies has lagged behind, notably in publications outside of evolutionary biology. Here I argue that some...

I absolutely love this paper from @stuartmcdaniel.bsky.social
It is a part of a must-read list for all new members of my lab.

Bryophytes are not early diverging land plants - McDaniel - 2021 - New Phytologist - Wiley Online Library nph.onlinelibrary.wiley.com/doi/10.1111/...

This is a deconvolved Z-maximum projection of an image captured on the FV3000 confocal microscope from Olympus using a 60x/1.2W objective.

The image shows a round protoplast filled with green, evenly distributed ovoid-shaped chloroplasts. In the center of the cell is the spherical nucleus in magenta.

Happy New Year, everyone. For this #microscopymonday, here is a moss (Physcomitrium patens) protoplast (wall-less cell) transformed with a nuclear marker (in magenta). The much brighter area is the nucleolus. The chlorophyll autofluorescence is in green.
#moss #plantcells

Today I made a small but momentous start to work in 2026 by changing a single number.

I renamed the file “Papers to write and submit in 2025” to “Papers to write and submit in 2026”.

Stay tuned for more file updates on 1st January 2027.

EMPIAR-11830 #ChlamyDataset #TeamTomo 🧪

www.cell.com/molecular-ce...

Fig. 1.Current expansion microscopy (ExM) methods in plant systems and other potential applications. Figure shows a schematic diagram of digested, permeabilized, expanded plant organelles, cells, or tissues embedded in a hydrogel in the center. Left panel showcases ExM techniques successfully applied in plant systems. These include chloroplast and nuclei (isolated organelles), Chlamydomonas, tobacco BY-2 cells, protoplasts, Arabidopsis seed embryos, and Arabidopsis roots. Right panel outlines other potential applications of ExM in other areas of plant biology including developmental biology, plant-microbe interactions, and spatial and single-cell biology. Created in BioRender. Cox, K. (2025) https://BioRender.com/ok72cvy.

🔬 EXPERT VIEW 🔬

In this review, Cox & Czymmek cover the recent developments of expansion microscopy techniques in plant systems and provides examples of their applications in plant biology research.

🔗 doi.org/10.1093/jxb/...

#PlantScience 🧪 @kcox-bioguy.bsky.social

Streptophyte terrestrialization and the conquest of land by embryophytes. Illustration adapted from Fig. 1 of de Vries & Archibald (2018; https://doi.org/10.1111/nph.14975) by Debbie Maizels.

Our #VirtualIssue on Plant terrestrialization focuses on piecing together #streptophyte trait #evolution and curating research that has contributed to advances in the evolutionary inference of (early) land plant form and function 👇

📚 nph.onlinelibrary.wiley.com/doi/toc/10.1...

#PlantScience

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A crucial step towards understanding tip growth in plants. Ivan Radin @radinbio.bsky.social (University of Minnesota) highlights work from Ryken et al. of the Bezanilla lab (rupress.org/jcb/article/...) in Spotlight: rupress.org/jcb/article/...

#CellSignaling #PlantBiology #PlantCellBiology

The image shows one Sundew plant in a pot surrounded by small green moss plants. The sundew plant is reddish in color and has leaves covered with sticky tentacles.

These amazing plants grow as small rosettes, and their leaves are covered with tentacles that secrete mucilage on the tips. The plants use the mucilage to adhere the insect prey long enough for the tentacles and the leaf to curve and entrap the prey.

The image shows a close-up of the tentacle tip from the leaf of a carnivorous sundew plant (Drosera spatulata). Tentacles are reddish in color and have a thin stalk with a large head at the end, which secretes a drop of clear mucilage that completely surrounds it.

The image shows a close-up of the tentacles from the leaf of a carnivorous sundew plant (Drosera spatulata). One is in the foreground and in focus, while the rest are blurry in the background. Tentacles are reddish in color and have a thin stalk with a large head at the end, which secretes a drop of clear mucilage that completely surrounds it.

These close-ups of mucilage-covered tentacle tips from the leaf of a carnivorous sundew plant (Drosera spatulata) definitely have a strong holiday vibe, so I am posting them just in time for the holidays. Happy Holidays.
#microscopymonday #carnivorousplants

Spotlight: Ivan Radin discusses new work from Ryken and colleagues (rupress.org/jcb/article/...) which shows how localization and function of autoinhibitory calcium ATPases maintains the strength of the tip-focus Ca2²⁺ gradient during polarized plant growth. rupress.org/jcb/article/...
#PlantBiology

Very true, but not all plant chloroplasts respond this way to beta-lactams, as likely not all plants have the peptidoglycan layer.

This is a deconvolved Z-maximum projection of an image captured on the FV3000 confocal microscope from Olympus using a 60x/1.2W objective.
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Magenta - chlorophyll autofluorescence, Green -mGFP-tagged protein targeted to the chloroplast envelope. The envelope can produce tubular protrusions called stromules, many of which are visible here. These are moss gametophore cells, many of which have only one giant chloroplast.
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The image shows large moss chloroplasts organized in irregular rows. The chloroplasts, in magenta, are somewhat rectangular in shape but with many irregularities. Many green tubular protrusions extend from the chloroplast surface.

This is what happens to the moss (Physcomitrium patens) chloroplasts when we grow cells on β-lactam antibiotics. β-lactams inhibit the synthesis of the peptidoglycan in the chloroplast envelope, leading to their dramatic expansion.
#microscopymonday #moss #plantcells #plantmicroscopy
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Tenure Track Professorship (W1 with Tenure Track to W3) in “Molecular Biology" (f/m/d) - Heidelberg job with Universität Heidelberg | 12850668 The Center for Molecular Biology of Heidelberg University (ZMBH) and the Faculty of Biosciences invite applications for a   Tenure Track Professors...

Please RT‼️ #TenureTrack position @zmbh.uni-heidelberg.de one of the best #proteostasis research centres in the world. www.nature.com/naturecareer...

This is a maximum projection of a Z-stack captured on the FV3000 point scanning confocal system using a 60x/1.3 silicon oil objective and subjected to deconvolution.

The plastids in the epidermal cells are smaller and accumulate more RecARed marker, hence are very bright. These plastids also produce a lot of protrusions, called stromules. The plastids from the deeper cells are bigger and have much more chlorophyll, so they appear greyer.

The image shows two types of plastids, bigger ones with an ovoid shape in grey, and much smaller ones with more complex structures in yellow/orange. The smaller ones also have many filamentous structures expanding from them.

The Arabidopsis thaliana cells can have different types of plastids. In this image, plastids are labeled with the stroma-targeted fluorescence marker RecARed. RecARed fluorescence is false-colored yellow/orange, while the chlorophyll autofluorescence is in grey.
#microscopymonday #plantcells

Thank you 😊

Thanks 😁

Fun fact: Moss caulonemal cells grow by adding new material to the tip region. This growth mechanism is called tip growth. In this region, vacuoles have complex tubule-like morphology, while in the rest of the cell, vacuoles are large and occupy most of the cell volume.