Transcriptional responses of Solanum lycopersicum to three distinct parasites reveal host hubs and networks underlying parasitic successes
Authors: Truch, J., Jaouannet, M., Da Rocha, M., Kulhanek-Fontanille, E., Van Ghelder, C., Rancurel, C., Migliore, O., Pere, A., Jaubert, S., Coustau, C., Galiana, E., Favery, B.
The study used transcriptomic profiling to compare tomato (Solanum lycopersicum) responses to three evolutionarily distant pathogens—nematodes, aphids, and oomycetes—during compatible interactions, identifying differentially expressed genes and key host hubs. Integrating public datasets and performing co‑expression and GO enrichment analyses, the authors mapped shared dysregulation clusters and employed Arabidopsis interactome data to place tomato candidates within broader networks, highlighting potential targets for multi‑pathogen resistance.
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 examined leaf pavement cell shape complexity across a natural European aspen (Populus tremula) population, using GWAS to pinpoint the transcription factor MYB305a as a regulator of cell geometry. Functional validation showed that MYB305a expression is induced by drought and contributes to shape simplification, with cell complexity negatively correlated with water-use efficiency and climatic variables of the genotypes' origin.
A genome‑wide association study of 187 bread wheat genotypes identified 812 significant loci linked to 25 spectral vegetation indices under rainfed drought conditions, revealing a major QTL hotspot on chromosome 2A that accounts for up to 20% of variance in greenness and pigment traits. Candidate gene analysis at this hotspot uncovered stress‑responsive genes, demonstrating that vegetation indices are heritable digital phenotypes useful for selection and genetic analysis of drought resilience.
Using laser ablation microscopy, the study dissected the role of the first cell row and a contiguous stem cell quorum in the apical notches of germinating Marchantia gemmae, revealing that these cells are essential for meristem activity and that apical notches communicate via auxin‑mediated signals to regulate dominance and regeneration. The findings support a model of intra‑, inter‑, and extra‑notch communication governing meristem formation and maintenance in Marchantia.
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 shows that nitrogen deficiency markedly elevates the exudation of the triterpenoid Solanoeclepin A (SolA) from tomato roots, a process that requires non‑sterile soil and involves the rhizosphere microbiota. Transient silencing of two candidate biosynthetic genes (CYP749A19 and CYP749A20) reduced SolA levels and impaired recruitment of beneficial Massilia spp., which promote plant growth under nitrogen limitation, indicating that SolA acts as a microbe‑mediated recruitment signal that was co‑opted by cyst nematodes.
The interplay between autophagy and the carbon/nitrogen ratio as key modulator of the auxin-dependent chloronema-caulonema developmental transition in Physcomitrium patens.
Authors: Pettinari, G., Liberatore, F., Mary, V., Theumer, M., Lascano, R., Saavedra, L. L.
Using the bryophyte Physcomitrium patens, the study shows that loss of autophagy enhances auxin‑driven caulonemata differentiation and colony expansion under low nitrogen or imbalanced carbon/nitrogen conditions, accompanied by higher internal IAA, reduced PpPINA expression, and up‑regulated RSL transcription factors. Autophagy appears to suppress auxin‑induced differentiation during nutrient stress, acting as a hub that balances metabolic cues with hormonal signaling.
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.