Charles Melnyk

Wound repair in plants guided by cell geometry Mathew et al. show that growth conflicts reshape cells after injury, forming rhomboidal geometries that trigger diagonal divisions. This reorients cell files to restore tapered morphology. A two-step ...

Our new paper is out!
1/14 How does an organ rebuild its shape after injury? It's not just about making new cells, but aligning them in the right direction — like bricks shaping a structure. We show that it's all driven by Cell Geometry!

www.cell.com/current-biol...

The hidden power of water in plant regeneration | Plantae Plants are renowned for their remarkable ability to regenerate tissues and organs. Two typical regeneration pathways—de novo root regeneration (DNRR) and wound-induced callus (WIC) formation—enable…

Plant Science Research Weekly -- The hidden power of water in plant regeneration (Nature Plants) @charlesmelnyk.bsky.social (Summary by Ching Chan) buff.ly/9quikax

#PlantaePSRW

Following herbivory, a plant releases volatiles that trigger jasmonate signaling in nearby plants. This leads to a change in the soil bacteria, which subsequently promotes growth, defense and yield in subsequent plants.

Plant Science Research Weekly: July 18, 2025 plantae.org/plant-scienc... (3/3) The hidden power of water in plant regeneration; ; Unusual cell death pathway in maize endosperm; Herbivore bites promote plant growth in the succeeding year. @matthiaserb.bsky.social @charlesmelnyk.bsky.social

Please spread the word: Position in plant development @umeaplantsciencecentre.se

Looking forward to having a new colleague!

www.upsc.se/jobs/6590-as...

Modern and historical uses of plant grafting to engineer development, stress tolerance, chimeras, and hybrids Plant grafting has been practiced for millennia and recent developments have resulted in new species, new techniques and new applications appearing. Here, we review these advances focusing on develop...

Interesting! Probably a piece of the Che was left on and grew back. Much less likely but maybe something chimeric or a hybrid? Chimeras have been seen in orange before (the Bizzarria). Have a look at these reviews:
onlinelibrary.wiley.com/doi/10.1111/...
www.sciencedirect.com/science/arti...

9/n. A collaborative effort with Abdul Kareem, Anna van Wüllen, Ai Zhang, Gabriel Walckiers and Ellen Fasth. A huge thanks to our funders @erc.europa.eu, @kawresearch.bsky.social and @vetenskapsradet.bsky.social for supporting and enabling this research!

8/n. An interesting outcome of this work is that high water availability is really good at regenerating roots and promoting in vitro regeneration (pubmed.ncbi.nlm.nih.gov/20230752). If you want to improve your in vitro regeneration rates, try using lower agar concentrations in your media.

Air layering of plants / RHS Air layering is a method of propagating new trees and shrubs from stems still attached to the parent plant. The stem is wrapped with damp moss to encourage roots to form.

7/n. What’s the relevance of this? We used air layering (www.rhs.org.uk/propagation/...) in tomato and found wet soil induced roots but dry soil induced callus. Thus, when wounds are in contact with water, roots form (think of plant propagation!) whereas under dry conditions, callus seals the wound

6/n. High water promoted ethylene and jasmonic acid responses, and these hormones could shift the auxin maxima away from the wound likely via PIN transporters. Thus, high water induced ethylene and jasmonic acid to change PIN localisation and move auxin maxima away from the wound to promote rooting

5/n. We found that water moved the auxin response maxima at the wound either away (distal) or towards (proximal) the cut. Distal response was associated with root formation while proximal response with callus formation. So the location of auxin response could induce different regeneration fates.

4/n. What decides whether a wound forms roots or callus? Water! By changing water availability, we could transition between these two fates. High water promoted roots near the wound, whereas low water promoted callus formation at the wound. These processes seemed to antagonise one another

3/n. Roots formed at wounds follow a lateral root formation pathway (pubmed.ncbi.nlm.nih.gov/24642937) but what about callus from wounds? We used reporters and mutants to find that callus follows a procambium pathway suggesting that different regeneration fates used different molecular pathways.

2/n. Regeneration is fundamental for plant survival but how do plants know what to regenerate? We sought to address this question using cut Arabidopsis petioles that can either form roots, callus or both at the site of wounding

Water availability positions auxin response maxima to determine plant regeneration fates - Nature Plants This study reveals that water availability at the wound determines plant regeneration outcomes. High water availability induces root regeneration whereas low water availability triggers callus formati...

How do plants decide the fate of a wound and what to regenerate? Water availability! Abdul Kareem and colleagues show that regeneration outcomes after tissue cutting are controlled by water. A 🧵/n 👇
www.nature.com/articles/s41...

Beautiful work showing opposing gradients of gases activates regeneration in wounded Arabidopsis roots. Congrats to all authors! Some interesting future questions raised regarding aerial tissues and non-Arabidopsis. How do they activate regeneration? Next big questions for the field.

Congratulations to all winners and finalists for their amazing science and excellent talks! I'm very pleased to be part of this group of scientists, and thankful to @mplantpcom.bsky.social for this award!

Just like in Fashion - trends are also returning in #PlantScience.

ATM, Grafting is coming back!

Two recent reviews were dedicated to it:

First, Augstein & @charlesmelnyk.bsky.social:
onlinelibrary.wiley.com/doi/10.1111/...

Then, @fritz-kragler.bsky.social & Bock:
www.nature.com/articles/s41...

Thanks Thomas and Hannes for highlighting our work. Great commentary and very well written!

Apoplastic barriers are essential for nodule formation and nitrogen fixation in Lotus japonicus Establishment of the apoplastic root barrier known as the Casparian strip occurs early in root development. In legumes, this area overlaps with nitrogen-fixing nodule formation, which raises the possi...

Finally!
Im so excited to present to culmination of many years of work from the fantastic Defeng Shen and some great collaborators. For details, I have made a digested thread below, but if you are more interested feel free to reach out (and read the paper of course).
www.science.org/doi/10.1126/...

The auxin–PLETHORA 5 module regulates wood fibre development in Populus tomentosa - Nature Plants The study reveals that PLETHORA 5, a transcription factor activated by auxin signalling in the vascular cambium, regulates cell expansion and cell wall thickening of fibres by directly repressing SND1...

Great paper by the group of lab alumnus Changzheng Xu on auxin regulation of fiber development in poplar.

www.nature.com/articles/s41...

Please check out our Commentary on the recent PNAS paper from the @charlesmelnyk.bsky.social lab about systemic signals in Phtheirospermum japonicum:
www.pnas.org/doi/10.1073/...

Thanks Suayb! 🙏

Postdoctoral Researcher (Faulkner Group) | John Innes Centre An exciting opportunity has arisen for a Postdoctoral Researcher to join the Faulkner Group at the John Innes Centre, working on cutting-edge science in the field of Cell & Developmental Biology.

We're looking for a postdoc to join the lab to work on cell-to-cell communication via the apoplast. Candidate must be brave, as they will have to lead us (me) away from the plasmodesmata-lands we've inhabited for so long!

www.jic.ac.uk/vacancies/po...

The position is fully funded for four years, open to applicants globally and has a start date of fall 2025. The application deadline is April 7th. A direct application link is below.
www.slu.se/en/about-slu...

A PhD position is available in my group @_SLU. Come join us in Uppsala, Sweden to work on plant regeneration and graft hybrid formation! Details below. Please share! #plantscijobs #PlantScience

🌱 When a root cell undergoes symmetric division, are the daughter cells actually identical? By combining live-cell imaging and scRNAseq we discovered a new cell state with uneven BR activity. Read our full paper in Cell: doi.org/10.1016/j.ce... @nvukas.bsky.social @trevormnolan.bsky.social

Investigation of genes regulating the intercalary meristem in barley at Durham University on FindAPhD.com PhD Project - Investigation of genes regulating the intercalary meristem in barley at Durham University, listed on FindAPhD.com

Please repost: BBSRC funded PhD opportunity. Please get in touch for further project info. www.findaphd.com/phds/project...

We are hiring! Are you interested in lateral root development and the cellular processes that accommodate these newly formed organs? If yes, apply! We are recruiting a Post-doc (from May 2025) and a PhD student (from September 2025).
www.unine.ch/lbmc/jobs/

"A long-distance inhibitory system regulates haustoria numbers in parasitic plants", our work is now out in @pnas.org. We propose that parasitic plants count their infection numbers, and dynamically regulate new infections in response. Read all about it:
www.pnas.org/doi/abs/10.1...

Our review on using grafting to engineer plants is out! Have a look in Plant Journal 👇