The study identifies the AP2/ERF transcription factor GEMMIFER (MpGMFR) as essential for asexual reproduction in the liverwort Marchantia polymorpha, showing that loss of MpGMFR via genome editing or amiRNA abolishes gemma and gemma cup formation, while dexamethasone‑induced activation triggers their development. Transient strong activation of MpGMFR initiates gemma initial cells at the meristem, which mature into functional gemmae, indicating MpGMFR is both necessary and sufficient for meristem‑derived asexual propagule formation.
The study employed ultra large‑scale 2D clinostats to grow tomato (Solanum lycopersicum) plants beyond the seedling stage under simulated microgravity and upright control conditions across five sequential trials. Simulated microgravity consistently affected plant growth, but the magnitude and direction of the response varied among trials, with temperature identified as a significant co‑variant; moderate heat stress surprisingly enhanced growth under simulated microgravity. These results highlight the utility of large‑scale clinostats for dissecting interactions between environmental factors and simulated microgravity in plant development.
The study generated a dataset of 420 sgRNAs targeting promoters, exons, and introns of 137 tomato genes in protoplasts, linking editing efficiency to chromatin accessibility, genomic context, and sequence features. Open chromatin sites showed higher editing rates, while transcriptional activity had little effect, and a subset of guides produced near‑complete editing with microhomology‑mediated deletions. Human‑trained prediction models performed poorly, highlighting the need for plant‑specific guide design tools.
Root-Suppressed Phenotype of Tomato Rs Mutant is Seemingly Related to Expression of Root-Meristem-Specific Sulfotransferases
Authors: Kumari, A., Gupta, P., Santisree, P., Pamei, I., Valluri,, S., Sharma, K., Venkateswara Rao, K., Shukla, S., Nama, S., Sreelakshmi, Y., Sharma, R.
The study characterizes a radiation‑induced root‑suppressed (Rs) mutant in tomato that displays dwarfism and pleiotropic defects in leaves, flowers, and fruits. Metabolite profiling and rescue with H2S donors implicate disrupted sulfur metabolism, and whole‑genome sequencing identifies promoter mutations in two root‑meristem‑specific sulfotransferase genes as likely contributors to the root phenotype.
The study reveals that REMORIN protein evolution is primarily driven by diversification of their conserved C-terminal domain, defining four major clades. Structural bioinformatics predicts a common membrane‑binding interface with diverse curvatures and lengths, and suggests that some REMs can form C‑terminal‑mediated oligomers, adding complexity to membrane organization.
An ancient alkalinization factor informs Arabidopsis root development
Authors: Xhelilaj, K., von Arx, M., Biermann, D., Parvanov, A., Faiss, N., Monte, I., Klingelhuber, F., Zipfel, C., Timmermans, M., Oecking, C., Gronnier, J.
The study identifies members of the REMORIN protein family as inhibitors of plasma membrane H⁺‑ATPases, leading to extracellular pH alkalinization that modulates cell surface processes such as steroid hormone signaling and coordinates root developmental transitions in Arabidopsis thaliana. This inhibition represents an ancient mechanism predating root evolution, suggesting that extracellular pH patterning has shaped plant morphogenesis.
A SABATH family enzyme regulates development via the gibberellin-related pathway in the liverwort Marchantia polymorpha
Authors: Kawamura, S., Shimokawa, E., Ito, M., Nakamura, I., Kanazawa, T., Iwano, M., Sun, R., Yoshitake, Y., Yamaoka, S., Yamaguchi, S., Ueda, T., Kato, M., Kohchi, T.
The study identified 12 SABATH methyltransferase genes in the liverwort Marchantia polymorpha and demonstrated that MpSABATH2 is crucial for normal thallus growth and gemma cup formation. Loss‑of‑function mutants displayed developmental phenotypes reminiscent of far‑red light responses, which were linked to gibberellin metabolism and could be partially rescued by inhibiting GA biosynthesis or supplying the GA precursor ent‑kaurenoic acid. These findings suggest that SABATH enzymes independently evolved regulatory roles in land‑plant development.
The study demonstrates that carbon availability promotes gemma cup formation in Marchantia polymorpha by activating cytokinin signaling, which up‑regulates the transcription factors MpGCAM1 and MpSTG. Pharmacological and genetic manipulations showed that cytokinin accumulation in response to sucrose and high light is sufficient to overcome low‑sucrose repression, and that this pathway operates independently of KAI2A‑MAX2 mediated karrikin signaling. The findings suggest a conserved carbon‑cytokinin interaction governing developmental plasticity across land plants.
The complete chloroplast genome of the endemic fruit species Dillenia philippinensis was sequenced, assembled, and annotated, revealing a 161,591‑bp quadripartite structure with 113 unique genes. Comparative analyses identified simple sequence repeats, codon usage patterns, and phylogenetic placement close to D. suffroticosa, providing a genomic resource for future breeding and conservation efforts.
The authors compiled and standardized published data on Rubisco dark inhibition for 157 flowering plant species, categorizing them into four inhibition levels and analyzing phylogenetic trends. Their meta‑analysis reveals a complex, uneven distribution of inhibition across taxa, suggesting underlying chloroplast microenvironment drivers and providing a new resource for future photosynthesis improvement efforts.