The histone in question is H3, one of the core proteins around which DNA is wound in every plant cell. At lysine 27, the twenty-seventh amino acid of that protein, the cell faces a fundamental choice. Acetylating this residue, essentially attaching a small chemical acetyl group to it, generally loosens the grip of chromatin and switches genes on. Deacetylating the same residue does the reverse, tightening the packaging and silencing the underlying DNA. For decades, textbooks have treated these two processes as opposing forces in a tug of war, with activating marks on one set of genes and repressive marks on another. The work highlighted by the Silesian team, originally reported by Iwase and colleagues in Molecular Plant, reveals something far more surprising: WIND1 appears to promote both sides of this chemical contest at the same time, and the cell is all the more responsive for it.

WIND1 is an AP2-family transcription factor first identified in Arabidopsis thaliana, the thale cress that serves as botany’s favorite laboratory workhorse. Its name betrays its origin story. When plant tissue is wounded, WIND1 springs into action, driving dedifferentiation, the process by which mature cells shed their specialized character and regain a stem-like, pluripotent state. This is the biological foundation of callus formation, the mass of undifferentiated cells that sprouts at wound sites and in tissue culture, and from which entire plants can ultimately be regenerated. Earlier studies had shown that WIND1 could induce callus not only in Arabidopsis but also in rapeseed, tomato and tobacco, hinting that its reprogramming power is broadly conserved among flowering plants.

What makes the new findings so compelling is the mechanism behind that power. According to the research summarized in the commentary, WIND1 simultaneously promotes histone H3 acetylation at lysine 27, known to chromatin biologists as H3K27ac, and induces the expression of genes associated with the embryogenic response. At the same time, the factor activates deacetylation of that very same histone mark and represses genes tied to differentiation. In other words, WIND1 does not simply flip a global switch from off to on. Instead, it acts like a master electrician rewiring a building, cutting power to the rooms that keep the cell locked in its old identity while flooding the rooms that define an embryo with light, all in one coordinated operation.

The context in which this reprogramming unfolds is somatic embryogenesis, the remarkable process by which vegetative cells, with no connection to flowers, ovules or seeds, are coaxed into forming embryos. Understanding the triggers of this embryogenic program remains, as the commentary’s authors put it, a major focus of modern molecular biology, and for good practical reasons. Somatic embryogenesis is widely used for clonal propagation of elite crops and forest trees, for cryopreservation of embryogenic material, and for genetic transformation, the insertion of new genes into plant genomes. A bibliometric analysis cited in the commentary counts more than nine thousand articles on somatic embryogenesis spanning fifty-five years, a testament to both the scientific fascination and the commercial stakes involved.

The economic dimension is hard to overstate. In conifers, where embryogenic tissue induction and maintenance remain stubborn bottlenecks, researchers are exploring small molecules to overcome the barriers. In citrus, recent work has shown that peptide signals can significantly enhance transformation efficiency even as they inhibit shoot regeneration, underscoring how finely balanced these developmental pathways are. In Europe, the micropropagation of economically important fruit species continues to face challenges that better mechanistic understanding could help solve. Woody species in particular depend on cryopreservation of embryogenic material for long-term conservation of genetic resources. Every insight into how cells are pushed into an embryogenic state therefore translates directly into faster, cheaper and more reliable propagation and breeding pipelines.

Against this backdrop, WIND1’s dual role in histone modification takes on real biotechnological significance. If the factor coordinates both acetylation and deacetylation to drive the embryogenic transition, then manipulating WIND1 or the enzyme complexes it recruits could make recalcitrant crop species far more amenable to regeneration and transformation. The commentary situates the finding within a broader landscape of research on developmental regulators that boost transformation efficiency in maize and other plants, and on the chromatin accessibility dynamics that underpin somatic embryogenesis. A hierarchical transcriptional regulatory network has been mapped for the process, and LEAFY COTYLEDON genes, especially LEC2, a B3-domain transcription factor famous for inducing embryo development when ectopically expressed, have long been recognized as essential players. WIND1 now emerges as a regulator that sits upstream of the epigenetic machinery itself, commanding the very chemical marks that open and close the genome.

The deeper conceptual payoff of the work may lie in how it reframes the biology of pluripotency. In animal systems, histone acetyltransferases and histone deacetylases are often studied as antagonists, and inhibitors of histone deacetylases are already in clinical use as cancer therapies, reflecting the power of tipping the acetylation balance. Plants appear to have evolved a more integrated solution: rather than relying on a global shift in one direction, the WIND1 pathway deploys both modifications in a targeted, gene-specific manner, activating embryogenic genes while silencing differentiation genes in the same cells at the same time. The commentary’s authors, whose work is supported by the National Science Centre of Poland under the OPUS 26 plus LAP call in the Weave program, emphasize that this coordinated integration of opposing marks is what enables the cell fate transition during somatic embryogenesis. It is a reminder that epigenetic regulation is less a switch than a symphony, with a single conductor drawing both crescendo and silence from the same orchestra.

There are also intriguing parallels with wound signaling beyond WIND1 itself. The peptide REF1 has recently been identified as a local wound signal promoting plant regeneration, and related peptides have been shown to enhance transformation in citrus. Wound-induced signals and chromatin remodeling evidently form a connected circuit: injury triggers molecular messengers, which activate transcription factors such as WIND1, which in turn remodel histone marks to unlock the embryogenic program. Even close relatives of WIND1 in other species, such as the AP2 transcription factor ThWIND1-L from the salt-tolerance relative Thellungiella halophila, suggest that this regulatory module is ancient and adaptable. As reviews of epigenetic regulation in plant regeneration make clear, the field is converging on a picture in which transcription factors and chromatin modifiers operate as an inseparable unit, with factors like WIND1 serving as the bridge between external signals and the epigenetic code.

For now, the commentary by Falińska, Nowak and Wójcikowska serves as both a synthesis and a provocation. It distills the message that the embryogenic transition in plants hinges on a transcription factor capable of directing opposing H3K27 modifications, and it challenges researchers to think of acetylation and deacetylation not as rivals but as partners in reprogramming. If that principle holds across species, the implications stretch from the tissue culture bench to the forest nursery and the crop field, wherever scientists seek to coax a mature cell back to the beginning. The question posed in the original title, to acetylate or to deacetylate, turns out to have a surprising answer: for WIND1, the answer is both, and that is precisely what gives the factor its power to rewrite a cell’s destiny.

Subject of Research: Epigenetic control of plant somatic cell reprogramming by the WIND1 transcription factor

Article Title: To acetylate or deacetylate? WIND1 directs opposing H3K27 modifications in plant somatic cell reprogramming

Article References: Falińska, J., Nowak, K., & Wójcikowska, B. (2026). To acetylate or deacetylate? WIND1 directs opposing H3K27 modifications in plant somatic cell reprogramming. Plant Molecular Biology, 116(5), Article 100. https://doi.org/10.1007/s11103-026-01765-z

Image Credits: AI Generated

DOI: 10.1007/s11103-026-01765-z

Keywords: WIND1, histone acetylation, H3K27, somatic embryogenesis, plant regeneration, epigenetics, transcription factor, pluripotency, chromatin remodeling, callus formation, Arabidopsis, plant biotechnology

Protoplasts are plant cells stripped of their rigid cellulose walls, usually digested free from leaf tissue by cocktails of commercial enzymes. Freed from the wall, they behave like single cells in culture: they can be fused with cells of other species to sidestep sexual incompatibility, transformed with gene-editing machinery such as CRISPR components, and pushed to regenerate entire plants through somatic embryogenesis. Because protoplasts can develop into plantlets faster and at larger scale than conventional callus-based micropropagation, they have long been attractive to breeders of crops where open-pollinated cultivars produce inconsistent yields, as is the case for carrot and many other members of the Apiaceae family. Carrot itself is a historic model in this field; the first protoplast isolation from carrot root slices was reported in 1972, and the species has since served as a workhorse for studies of somatic hybridization, cytoplasmic male sterility, and transformation.

The new study compared two carrot varieties, the hybrid Champion F1 and the male-sterile Naigara, using leaves from aseptically grown seedlings as the starting material. Leaf tissue avoids the laborious cell suspension cultures traditionally used for carrot protoplasts, which can take three to eight months to establish and have historically delivered plating efficiencies of twenty percent or less. Leaves of three- to four-week-old seedlings were finely chopped, plasmolyzed in mannitol solution, and digested overnight with enzyme mixtures built around Cellulase Onozuka R-10, Macerozyme R-10, and Pectolyase Y-23. Released protoplasts, roughly 22 micrometers in diameter and green with randomly distributed chloroplasts, were sieved, pelleted by gentle centrifugation, and purified on a sucrose gradient before counting in a hemocytometer.

The enzyme recipes mattered, and in a variety-dependent way. For Naigara, the mixture of one percent Cellulase Onozuka R-10 with 0.1 percent Pectolyase Y-23 yielded 2.29 million protoplasts per gram of fresh leaf, while a stronger mixture of two percent cellulase with 0.2 percent Macerozyme R-10 raised the yield to 3.74 million per gram. Champion F1 showed the opposite trend: the pectolyase-based mixture delivered the best result, 4.9 million protoplasts per gram, nearly double the 2.42 million obtained with the macerozyme recipe. Viability, assessed by fluorescein diacetate staining under a fluorescence microscope, exceeded 70 percent in all cases, peaking at 87.5 percent for Champion F1 with the pectolyase mixture. The authors attribute the different responses of the two varieties primarily to variations in cell wall structure, a reminder that even within a single species, protoplast work remains a bespoke craft. The yields reported are comparable to those in prior Daucus studies, which have ranged from roughly 1.3 to 5.9 million protoplasts per gram across species and varieties.

The bitter gourd result is the study’s most novel contribution. Bitter gourd is valued across Asia for both nutrition and medicinal compounds, but its long juvenile phase, resistance to transformation, and variety-dependent regeneration protocols have hampered conventional breeding. The team tested ten different enzyme combinations on leaves of the open-pollinated variety KSP 1522, and only one recipe, combining 1.5 percent Cellulase Onozuka R-10 with 0.2 percent Macerozyme R-10, worked. The protoplasts proved highly sensitive: most other enzyme treatments either failed to liberate cells or produced protoplasts that burst during centrifugation. The successful combination yielded 1.18 million protoplasts per gram, about 24 micrometers in diameter, with viability of just over 80 percent that declined only modestly, by around eight percent, after 24 hours. Because viability above roughly 65 percent is generally considered sufficient for regeneration, the authors present this as a foundational protocol, while cautioning that it is optimized for this specific variety and explant, and that yields remain sub-optimal pending further refinement.

For carrot, the team went beyond isolation and demonstrated the full pipeline from naked cell to field-ready root. Protoplasts were embedded in thin layers of calcium alginate, a technique that protects the fragile cells, allows undisturbed cell walls to regenerate, prevents clumping, and improves mass transfer of nutrients because the matrix is thin. Within four to six weeks, visible macrocolonies emerged, developed into proembryonic masses, and then differentiated into globular, torpedo, and cotyledonary-stage somatic embryos over one to two months. Embryos were released from the alginate with a mannitol and sodium citrate solution and transferred to regeneration medium containing zeatin and naphthaleneacetic acid. Plantlets appeared within weeks, and germination frequency was so high that thousands of plantlets, too many to count individually, were produced. Of 332 plantlets hardened off in cocopeat under gradually reduced humidity, 319 survived acclimatization, a 96 percent success rate with no morphological abnormalities.

The cold storage experiments are arguably the most practically significant. Plant genetic resources are conventionally conserved as seeds, field collections, or in vitro cultures, with cryopreservation in liquid nitrogen as the gold standard for recalcitrant material. But cryopreservation is expensive, technically demanding, and, for carrot protoplasts, previously documented only once, with a colony-forming capability of just 19 percent after six months in liquid nitrogen. The Indian team instead stored Champion F1 protoplasts in carrot petiole protoplast medium at ordinary refrigerator temperatures of 2 to 8 degrees Celsius. After five months, the protoplasts were still viable by FDA staining, although exact counts were complicated by clumping, and they showed partial cell division upon rewarming. When embedded in alginate and cultured, the cold-stored protoplasts regenerated into plantlets within a week of transfer to regeneration medium.

The outcome of that regeneration pipeline was remarkable: from 253 plants hardened after regeneration from five-month-old cold-stored protoplasts, 216 survived acclimatization, an 85 percent efficiency. The regenerated plants completed a three-month growth cycle and produced healthy orange carrots, confirming that the entire pathway, from wall-less cell stored in a refrigerator to harvestable storage root, can function without cryogenic equipment. The authors are careful to note the limitations: the study rests on only two data points, and systematic work across longer storage durations with multiple time points will be needed to establish how far this simple approach can be pushed.

Taken together, the results offer breeding programs a practical toolkit. Reliable leaf-based protoplast isolation eliminates the need for long-lived suspension cultures; demonstrated cold storage at 2 to 8 degrees Celsius gives labs a low-cost buffer for scheduling fusions, transformations, and regeneration experiments weeks or months apart; and the first protoplast protocol for bitter gourd opens a route toward transgene-free genome editing in a crop whose medicinal value and breeding difficulties have long made it a difficult target. With CRISPR components already shown to be deliverable to protoplasts, and gene-edited carrots previously produced via protoplast transformation, the ability to isolate, bank, and regenerate these cells on demand brings somatic hybridization and precision editing for both crops a step closer to routine practice.

Subject of Research: Protoplast isolation, cold storage and plant regeneration in carrot and bitter gourd

Article Title: Protoplast isolation in Daucus carota and Momordica charantia: regeneration and cold storage studies in carrot

Article References: Ranaware, A. S., Kushwaha, S. B., Kunchge, N., Prakash, G., & Lele, S. S. (2025). Protoplast isolation in Daucus carota and Momordica charantia: regeneration and cold storage studies in carrot. Discover Biotechnology, 2(1), Article 24. https://doi.org/10.1007/s44340-025-00034-x

Image Credits: AI Generated

DOI: 10.1007/s44340-025-00034-x

Keywords: protoplasts, carrot, bitter gourd, Daucus carota, Momordica charantia, plant regeneration, somatic embryogenesis, cold storage, tissue culture, cellulase, plant breeding, CRISPR