Ivan Radin

That is a good question. We don't know the exact functions of stromules. They are often part of Plant immune response. 😄

Stromules are visible due to the stroma-targeted fluorescent marker (in green). Stromules are comprised of both envelope membrane and stroma, but not chlorophyll-containing thylakoid membranes, visible here in magenta due to autofluorescence. The image was captured on an FV1000 confocal from Olympus

The image shows several chloroplasts in green and magenta or both. In the center of the image, five chloroplasts are organized in a circle, and each is making a protrusion towards the center of the circle. The center of these chloroplasts is in magenta, while the periphery and the protrusions are in green.

In preparation for Halloween, these chloroplasts had a seance! 👻🎃
These five Arabidopsis chloroplasts were extending their stromules (protrusions of the chloroplast envelope and stroma) towards each other.
#microscopymonday #Arabidopsis #plantcells #plantmicroscopy

Genetically engineered color-changing Arabidopsis 🧬📷- attempt #3

I think I finally nailed it with this one.

Forgot to add in my original post that these are caulonema cells. 😀

This is a maximum projection of a Z-stack captured on the FV3000 point scanning confocal system from Olympus/Evident using a 20x/0.75 objective and subjected to deconvolution.

The calcofluor white stained cell wall is shown in cyan, while the chlorophyll autofluorescence is in magenta.
This juvenile moss cell is characterized by apical growth, where new material is only added to the tip, while the rest of the cell is not growing. Some subapical cells can divide again.

Image shows a filament of three elongated moss cells. The cell outline is in cyan, due to the cell wall staining, while the cell interior appears mostly empty apart from the small and numerous ovoid-shaped chloroplasts in magenta.

This image of moss Physcomitrium patens beautifully demonstrates what we mean when we say that this cell type is characterized by oblique cell walls.
You can see that the cell walls between cells are at an angle and not perpendicular to the cell axis.
#microscopymonday #moss #plantcells

Thank you 😊

This is a maximum projection of a Z-stack captured on the Olympus FV3000 confocal with the 60x/1.2 W objective from Olympus/Evident.

The image shows several elongated rhomboid-shaped cells, filled with ovoid chrooroplasts in magenta, as well as a network of bubble-like vacuoles.

Here are some “leaf” or phyllid cells from moss Physcomitrium patens gametophore. Cells are expressing a green fluorescence marker that labels the vacuolar membrane. Chloroplasts' autofluorescence is in magenta.
Can you spot dividing chloroplasts?
#microscopymonday #moss #plantcells

I started to work on MscS-Like proteins 20 years ago, dreaming that they were involved in plant mechanotransduction. And it is becoming more & more clear that they are!
#plantscience 🧪
"DmMSL10 is crucial for mechanosensing, facilitating AP firing by generating a receptor potential (RP) amplitude."

Inside a thylakoid membrane

The molecular architecture of the thylakoid membrane in a vascular plant has been determined with single-molecule precision.
buff.ly/U9TzrOh

Fun fact: In mature plant cells, vacuoles occupy most of the cell volume (>90%). The entire cytosol of two neighboring cells and their shared cell wall, are squished into small spaces between two large vacuoles you can see in parts of the image.

The formation of the brighter green bulbs inside the vacuolar lumen is promoted by dimerization of EGFP in the vac-GB marker. However, some types of bulbs can occur in the WT plants, even without the marker.
The image was captured on the FV1000 confocal system from Olympus.

The image shows epidermal Arabidopsis cells (shaped like puzzle pieces) outlined by green lines. Some cells have bright green within them. Ovoid-shaped chloroplasts in magenta are visible throughout the image.

This is a section of the cotyledon (first leaf) surface from the flowering plant Arabidopsis thaliana, which is expressing the green fluorescent protein vacuolar membrane marker (vac-GB). Chloroplasts are in magenta, visible due to the autofluorescence of the chlorophyll.
#microscopymonday

YouTube video by Plant Cell Atlas Imaging Workshop Webinar Series: FIJI Basics for Visualizing and Quantifying Plant Images

In case you missed it, our workshop on Fiji Basics for Visualization and Quantification of Plant Images is now available on YouTube:
www.youtube.com/watch?v=4TMJ...
We give a lot of practical tips on how to get started with Fiji.
Keep an eye out for announcements on follow-up workshops.

Protoplasts are always fascinating to look at 😄

Promotional image for the PCA Imaging Workshop Webinar Series: FIJI Basics for Visualizing and Quantifying Plant Images. The promo has a purple and green plant cell graphic with a black background. It also includes the details for the webinar including the date/time: Wednesday September 24, 2025 9:30am CT/10:30am ET/7:30am PT, the Zoom Link, and the Organizers: Ivan Radin, Kirk Czymmek, and Daniel Kierzkowski.

In Two Days!

Attendees: we encourage you to download and install FIJI in advance of the workshop if you wish to follow along on your own computer. Keep an eye on your email & visit:
hpc.nih.gov/apps/Fiji and fiji.sc

Register Now! bit.ly/45zJE7V

Only some of the protoplasts were successfully transformed.
This is a maximum projection of a Z-stack captured on the FV3000 point scanning confocal system using a 20x/0.75 objective and subjected to deconvolution.

The image shows many perfectly spherical cells (protoplasts). All of them are filled with numerous oval-shaped chloroplasts in grey. Some also have orange signal filling either the whole sphere or only part of it.

This is what happens when you remove the wall from plant cells. They become perfectly spherical and are called protoplasts.
These protoplasts were isolated from Arabidopsis and transformed with a vector to express cytosolic GFP (in orange). The chloroplast autofluorescence is in grey.
#microscopy

Glad to hear that. I try to add as much as I can about plant electrical and calcium signaling to my lectures too 😄

Session 2 (Times are North American Central Daylight Time)

Tuesday, October 28, 2025
9:00 a.m. - 10:00 a.m.
9:00 a.m. - Preparing a strong application: Advice from admissions committee members
9:15 a.m. - Open, drop-in Q&A with current PMB students
Zoom link: umn.zoom.us/j/95884546895

Session 1 (Times are North American Central Daylight Time)

Thursday, October 23, 2025
2:00 p.m. - 3:00 p.m.
2:00 p.m. - Preparing a strong application: Advice from admissions committee members
2:15 p.m. - Open, drop-in Q&A with current PMB students
Zoom link: umn.zoom.us/j/95884546895

Our Plant and Microbial Biology Graduate Program (cbs.umn.edu/pmb/graduate...) is organizing two Zoom Admissions open houses where you can learn about preparing a strong application and get advice about graduate school from current PMB students.
Drop in at any point on either or both days, see below

🤩

Thank you 😁

Thank you 😁

Sundews need to be very sensitive to touch, to recognize when their prey has been captured.
This project was a great collaboration with Carl Procko from @salkinstitute.bsky.social. Videos were captured with the THUNDER Imager Model Organism dissecting scope from @leicamicrosystems.bsky.social

These sundews (Drosera spatulata) plants are expressing a cytosolic calcium biosensor. The video is false-colored, where the color corresponds to the calcium concentration in the cytosol of the cells. Blue = lowest, green = medium, and yellow = highest calcium levels
doi: 10.1073/pnas.2206433119