Leonardo Castanedo

🛑Exciting update from our work with PM Delaux team on the ericoid mycorrhizal symbiosis❗ 🔥New results support a conserved three-gene module and master regulator for nutrient-responsive intracellular accommodation of fungal symbionts🤯 A nice thread below👇🏼 #plantscience

The amount of fraud in education research at elite universities should get way more attention

I’m looking for an automated way to read others’s scientific data without giving credit or acknowledgement, and also claim full credit for insights from it. And I want it to have a fitting name OAI: say no more

In back-to-back papers, our lab and the Casal lab tackle the question: How does temperature reshape auxin-driven growth? Together, we reveal that temperature directly rewires ARF behavior. nature.com/articles/s4146…

Hiding in plain sight! 2.3M conserved non-coding sequences traced back 300M years across 284 plant species Ground-breaking study in First Release @ScienceMagazine from labs of Madelaine Bartlett, Idane Efroni & Zach Lippman ▶️ doi.org/10.1126/scienc… ▶️ slcu.cam.ac.uk/news/hiding-pl…

"We do not treat co-transcription of polycistronic operons in these simulations; each gene is transcribed independently." LOL

Thrilled to see this paper in print: Chromosome-scale Genome Assembly of the Most Abundant Ectomycorrhizal Fungus Cenococcum Geophilum Reveals Massive TE Expansion and RIP Defense Mechanism | Genome Biology and Evolution academic.oup.com/gbe/article/18…

This paper on a self-replicating ribozyme is indeed cool, but there was a preprint posted in October of 2024 biorxiv.org/content/10.110… that got very little attention. The lesson READ PREPRINTS AND DON'T WASTE 18 MONTHS!! science.org/doi/10.1126/sc…

The Toxicity of applied pesticides is increasing worldwide reports an important new paper by Wolfram et al. published this week in Science. It appears that especially in Africa, parts of the USA, Asia and South America toxicity levels have increased greatly (see figure below). see: lnkd.in/gdXce4fT It links to our recent paper reporting widespread occurrence of pesticides in Europe and that pesticides have a major impact on soil biodiversity (lnkd.in/gHt5Dzzx).

Can plant pathogens boost vector fitness? Together with @HassanSalem, we review how phytopathogens can spread further by moonlighting as insect symbionts 🪲 More on this nifty lifestyle in @AnnualReviews! annualreviews.org/content/journa…

science.org/doi/10.1126/sc… Some mosses, in association with algae and bacteria, form tower-like structures more than 80 cm high, underwater Antarctic lakes. I always thought it looked very similar to Devonian giant organism #Protataxites. But, I must change my mind.

New Brief Communication: "A CRISPR-based sequence proximity binding protein labelling system for scanning upstream regulatory proteins" rdcu.be/eZLUP CRISPR-based proximity labelling system to profile DNA-binding proteins such as PIF4 transcription factor .

This paper is wild. After 3 rounds of directed evolution, they converted a DNA polymerase into an enzyme that can do: - RNA synthesis - Reverse transcription - Synthesis of "unnatural" nucleotides - Synthesis of DNA-RNA chimeras One of the best papers I’ve read recently. For context: In nature, it is DNA polymerase that takes a DNA sequence as a template and then copies it. These enzymes are crucial in replicating the genome for cell division, and they are EXTREMELY specific for DNA over RNA. This is key because RNA nucleotides are present in the cell at concentrations ~100x higher than DNA nucleotides, so the enzyme has evolved clever strategies to select one over the other. RNA polymerases, for comparison, are the enzymes that take a DNA sequence as template and then convert it into RNA. They are involved in gene expression, for example. To convert a DNA polymerase into an RNA polymerase (and all the other functions I mentioned earlier), the authors did a fairly straightforward directed evolution experiment. First, they took four DNA polymerase enzymes belonging to various archaea. These DNA polymerases don’t check for DNA vs. RNA as stringently as other types of cells, so they’re a good starting point to evolve RNA polymerases. The authors inserted some targeted mutations into these enzymes, based on known mutations in the literature. For example, they swapped the amino acid at position 409 for a smaller amino acid, thus removing a “gate” that keeps RNA building blocks from entering the enzyme. Next, they took the four genes encoding these DNA polymerases and cut them up into 12 segments each. They randomly stitched these 12 segments together — from the four different genes — to build millions of unique variants. Each shuffled gene was inserted into an E. coli cell. Then, they grew up these cells (each carrying a unique polymerase) and put them into microfluidic droplets. A device isolates each droplet, lyses the cell open, and releases the polymerase. The droplet also contains RNA building blocks and a DNA template, encoding a fluorescent reporter. If the polymerase begins synthesizing RNA, it will produce a detectable signal. They screened about 100 million droplets in 10 hours of work, searching for those with a signal. For each well that yields a fluorescent signal, the researchers isolated the DNA and sequenced it to figure out which polymerase it was. They repeated this 3x times, finally isolating a really excellent RNA polymerase variant which they called "C28." C28 has 39 mutations compared to the wildtype enzymes. It incorporates about 3.3 nucleotides of RNA per second, with 99.8% fidelity. The crazy thing is that this enzyme can also copy DNA or RNA templates back into DNA (reverse transcription), or use chimeric DNA-RNA molecules as a template and amplify them. It is just a super versatile polymerase that can act on DNA, RNA, or modified nucleotides, to build just about anything.

The molecular basis of the binding and specific activation of rhizobial NodD by flavonoids | Science science.org/doi/10.1126/sc…

Call for manuscript submissions for a new special issue in Environmental and Experimental Botany entitled "Ecophysiology of metal and metalloid hyperaccumulator plants". Submission deadline is 1 August 2026 sciencedirect.com/special-issue/…

New opportunity to join our #EvoMPMI group @JohnInnesCentre as a Postdoctoral Researcher working in the mechanistic basis of immunity in diverse plants. Please spread the word, reach out by email, and/or apply if interested! More details here: jic.ac.uk/vacancies/post…

Advanced imaging reveals arbuscular mycorrhizas in 407-million-year-old plant from Scotland @NewPhytologist @dromius @FFercoq @victorleshyk doi.org/10.1111/nph.70…

Grateful to the whole team @LRSV_Toulouse who made this work possible! Our results fill a major knowledge gap in how endosymbiotic interactions diversify in plants and reveal molecular basis of nutrient-dependent regulation 🦠🌱!

🛑Exciting update from our work with PM Delaux team on the ericoid mycorrhizal symbiosis❗ 🔥New results support a conserved three-gene module and master regulator for nutrient-responsive intracellular accommodation of fungal symbionts🤯 A nice thread below👇🏼 #plantscience

This Halloween, we have a spooky evolutionary story for you. The brainchild of @delaconcepcionj @dinokaryon & our fantastic collaborators is now out in @NaturePlants nature.com/articles/s4147… Here’s why I love this work — and why I think you’ll enjoy it too. 👇

Genetically engineered plant endophytes broaden effector-triggered immunity "The oxyR circuit responds to infection-induced ROS by producing effectors recognized by existing NLRs, activating immunity against even pathogens lacking recognizable effectors" sciencedirect.com/science/articl…