The actin cytoskeleton is required to maintain plant cell division orientation against cellular geometry Actin guides plant cell division, shaping tissues in ways that defy geometric constraints.

What a treat to see the work from Camila Goldy @camilagoldy.bsky.social et al., @rdplab.bsky.social @ensdelyon.bsky.social now published 🫶

www.science.org/doi/10.1126/...

🌱✂️ How do plant cells decide where to divide?

Our work shows that actin can override the geometric rules—guiding cells to divide in alternative orientations.
#PlantScience #CellBiology #Arabidopsis

@camilagoldy.bsky.social @rdplab.bsky.social

www.biorxiv.org/content/10.1...

Brassinosteroid controls leaf air space patterning non-cell autonomously by promoting epidermal growth www.biorxiv.org/content/10.1101/2025.07....

Asymmetric cell division: (re) visiting the concept in light of brown algae 🧲review in Curr Op Plant Biol doi.org/10.1016/j.pb...

Incredible Molly Herring wrote a story on the philosophy behind the work we do at PrakashLab. Wonder & curiosity.. even more important to share when every day is a new attack on the fundamental principles of scientific explorations. Thanks @quantamagazine.bsky.social for this interaction.

🚀 Big news!
I’m happy to share with you the launch of MIAtecs’ brand-new website: www.miatecs.com 🌿

If you work in plant #phenotyping, #microscopy, or #AI-based image analysis, especially around #stomata, #trichomes, or other hard-to-capture traits, it’s worth a visit! 😊

Can Germany rein in its academic bullying problem? Researchers and administrators are exploring ways to restructure a rigid hierarchy that can breed power abuses.

Good article on academic bullying (it's not just a German problem).
www.nature.com/articles/d41...

Please Repost! We are offering a three-year fully funded doctoral researcher position to study how floral meristem patterning in woodland strawberry, and how it implicates the diversification in floral ground plans in Angiosperm flowers. jobs.helsinki.fi/job/Helsini-...

A grey coloured Arabidopsis leaf epidermis, with black cell walls. Each cells has a colourful blobs - a nuclear localised fluorescent ABA sensor, with warm colours indicating high concentrations, and cooler colours indicating lower concentrations.

The Rowe lab is recruiting a #PlantScience PhD student for 2025! You'll use our new ABACUS FRET biosensors to map the leaf #AbscisicAcid accumulations at low humidity in Arabidopsis, wheat and rice to understand how ABA regulates stomatal dynamics. #PhDposition

www.findaphd.com/phds/project...

Stunning corset-like structure made of cell wall #alginate might restrict lateral growth in #kelp embryos. ➡️ www.nature.com/articles/s41...

Please spread the word, 2-year-postdoc position in my group to understand fate determination.
www.upsc.se/jobs/6548-po...

Thank you Jim!

This was a nice and fun journey with great colleagues and a supportive PI @robinsonsci.bsky.social, it would not have been possible without the fantastic working environment of @slcuplants.bsky.social 12/12

Altogether these experiments allowed us to conclude that stomata were aligned by mechanical stress derived from differential growth 11/12

Since these approaches couldn’t rule out a wounding effect, we’ve decided to use a more gentle approach: tissue folding. Again we observed a change of division orientation after folding 10/12

At this point, we thought that mechanical stress could be the “mysterious factor” orienting stomata division, so we performed mechanical perturbations (stabbing or slicing with a needle), which led to a nice change in division orientations 9/12

This range of techniques allowed us to identify a drastic change of cotyledon curvature between 1 and 2 DAG, this change is associated with differential growth between the 2 sides and orthogonal stress patterns 8/12

Since we’ve found different orientation patterns between the 2 sides of cotyledons we decided to characterize the 2 sides in more detail to try to find the mysterious factor orienting stomata. For this, we used light sheet imaging, dual-view timelapse imaging, full 3D segmentation, and FEM 7/12

We time-lapsed cotyledons during stomata division and analyzed the orientation of division, on the abaxial side we found that the divisions were aligned with the organ axis and not with the cell major axis or growth direction, on the adaxial side the division were more disorganized 6/12

And rather than just looking at a few stomata divisions, we’ve made all epidermal cells turn into stomata using the iMUTE inducible line (Han et al 2018), that’s much funnier 5/12

After this characterization, we asked our big question: What factor is directing the orientation of stomata division? Our suspects were cell geometry, cell growth direction, or organ axis. 4/12

On the abaxial side, the organ scale alignment is quite obvious in the early stages, but the stomata formed later in development have more random orientations. We’ve also looked at the adaxial side, and interestingly 2 days after germination the new stomata are not aligned anymore 3/12

We first characterized the stomata orientation pattern in Arabidopsis Cotyledons, for this, we’ve manually annotated more than 10000 stomata (that’s a lot of clicking) and mapped their orientation relative to the proximo-distal axis. Here are some of these maps on the abaxial side 2/12

More details on our recent pre-print:
Alignments of stomata have been described in many species, here are 2 examples: Thym from my kitchen, and Leucadendron from a 1935 paper (Smith 1935 on the orientation of stomata)
What is directing these alignments is unknown 1/12
doi.org/10.1101/2024...

Stomata form alignments in many species, we do not know how. So, we forced a lot of cells to differentiate into stomata, and we watched them dividing, with modelling, and mechanical perturbations, we conclude that they were aligned by mechanical stress derived from differential growth

High speed video showing the ejection of seeds by the squirting cucumber (Ecballium elaterium). The video is captured at 8,600 fps, and is slowed down around 350 times.

How does the squirting cucumber squirt?

New research has found the answer! It turns out that four key components make up a finely tuned seed dispersal system 👇
bit.ly/4g5stil

A grey coloured Arabidopsis leaf epidermis, with black cell walls. Each cells has a colourful blobs - a nuclear localised fluorescent ABA sensor, with warm colours indicating high concentrations, and cooler colours indicating lower concentrations.

The Rowe lab is recruiting a #PlantScience PhD student for 2025! You'll use our new ABACUS FRET biosensors to map the dynamic leaf #AbscisicAcid accumulations at low humidity in Arabidopsis, wheat and rice. #PhDposition

www.findaphd.com/phds/project...

Schematic displaying stomatal development in wild type (WT). Stomatal development starts with guard mother cell (GMC; blue) formation. BdMUTE is expressed in the GMC (light blue nucleus) and moves into the lateral cells (light yellow nucleus) to establish subsidiary mother cells (SMCs). SMCs then polarize (yellow gradient) and divide asymmetrically to form lateral SCs (yellow). Finally, the GMC divides symmetrically to generate two GCs (light green), which form a pore and mature into the characteristic dumbbell shape (dark green). Open questions regarding BdMUTE’s roles and mechanisms are indicated.

Excited to share our new #preprint on BdMUTE and its dual role in recruiting subsidiary cells (SCs) and orienting guard cell (GC) division in #Brachypodium: biorxiv.org/content/10.1... We set out to answer questions about how BdMUTE influences grass stomatal development: (1/8)

3-year post-doc on control of cell division orientation in brown algae, in Charrier's group @ IGFL, ENS Lyon, France (bsky.app/profile/igfl...)
Job description : ->https://rb.gy/dt0aq9