Tomato leaf transcriptomic changes promoted by long-term water scarcity stress can be largely prevented by a fungal-based biostimulant
Authors: Lopez-Serrano, L., Ferez-Gomez, A., Romero-Aranda, R., Jaime Fernandez, E., Leal Lopez, J., Fernandez Baroja, E., Almagro, G., Dolezal, K., Novak, O., Diaz, L., Bautista, R., Leon Morcillo, R. J., Pozueta Romero, J.
Foliar application of Trichoderma harzianum cell‑free culture filtrates (CF) increased fruit yield, root growth, and photosynthesis in a commercial tomato cultivar under prolonged water deficit in a Mediterranean greenhouse. Integrated physiological, metabolite, and transcriptomic analyses revealed that CF mitigated drought‑induced changes, suppressing about half of water‑stress responsive genes, thereby reducing the plant’s transcriptional sensitivity to water scarcity.
The study engineers Type‑B response regulators to alter their transcriptional activity and cytokinin sensitivity, enabling precise modulation of cytokinin‑dependent traits. Using tissue‑specific promoters, the synthetic transcription factors were deployed in Arabidopsis thaliana to reliably increase or decrease lateral root numbers, demonstrating a modular platform for controlling developmental phenotypes.
The study profiled root transcriptomes of Arabidopsis wild type and etr1 gain-of-function (etr1-3) and loss-of-function (etr1-7) mutants under ethylene or ACC treatment, identifying 4,522 ethylene‑responsive transcripts, including 553 that depend on ETR1 activity. ETR1‑dependent genes encompassed ethylene biosynthesis enzymes (ACO2, ACO3) and transcription factors, whose expression was further examined in an ein3eil1 background, revealing that both ETR1 and EIN3/EIL1 pathways regulate parts of the network controlling root hair proliferation and lateral root formation.
Exogenous Hormone Treatments Reveal Species-Specific Regulation of Individual Components of Root Architecture and Salt Ion Accumulation in Cultivated and Wild Tomatoes
Authors: Rahmati-Ishka, M., Craft, E., Pineros, M., Julkowska, M. M.
The study examined how individual hormone treatments (auxin, ethylene, gibberellin) influence root architecture and ion accumulation under salt stress in three tomato accessions, revealing species-specific hormonal effects on lateral root development and Na/K ratios. Genetic analyses using Arabidopsis mutants and a tomato ethylene‑perception mutant (nr) identified novel hormonal signaling components that modulate salt stress responses, highlighting potential strategies to improve crop performance.
The study performs a bibliometric analysis of 1,702 Scopus-indexed tomato omics publications over two decades, revealing a rapid surge in output after 2017 and highlighting dominant fields such as biochemistry, genetics, and molecular biology. Citation and co‑authorship network analyses identify key contributions in microRNA research and genome sequencing, major research hubs, and collaborative clusters, while keyword mapping underscores stress response, fruit quality, and immunity as priority topics.
The study characterizes the tomato class B heat shock factor SlHSFB3a, revealing its age‑dependent expression in roots and its role in enhancing lateral root density by modulating auxin homeostasis. Overexpression of SlHSFB3a increases lateral root emergence, while CRISPR‑mediated knockouts produce the opposite phenotype, indicating that SlHSFB3a regulates auxin signaling through repression of auxin repressors and activation of the ARF7/LOB20 pathway.
A forward genetic screen in light-grown Arabidopsis seedlings identified the Evening Complex component ELF3 as a key inhibitor of phototropic hypocotyl bending under high red:far-red and blue light, acting upstream of PIF4/PIF5. ELF3 and its partner LUX also mediate circadian regulation of phototropism, and the orthologous ELF3 in Brachypodium distachyon influences phototropism in the opposite direction.
The study investigates the altered timing of the core circadian oscillator gene ELF3 in wheat compared to Arabidopsis, revealing that dawn-specific expression in wheat arises from repression by TOC1. An optimized computational model integrating experimental expression data and promoter architecture predicts that wheat’s circadian oscillator remains robust despite this shift, indicating flexibility in plant circadian network design.
The study investigated how Arabidopsis thaliana SR protein kinases (AtSRPKs) regulate alternative RNA splicing by using chemical inhibitors of SRPK activity. Inhibition with SPHINX31 and SRPIN340 caused reduced root growth and loss of root hairs, accompanied by widespread changes in splicing and phosphorylation of genes linked to root development and other cellular processes. Multi‑omics analysis (transcriptomics and phosphoproteomics) revealed that AtSRPKs modulate diverse splicing factors and affect the splicing landscape of numerous pathways.
The study tests whether the circadian clock component ELF3 shapes developmental trait heterogeneity, proposing that faster‑developing populations are more heterogeneous early but less so at maturity, whereas slower growers show the opposite pattern. Experiments with Arabidopsis elf3 and barley Hvelf3 mutants confirmed these predictions, showing ELF3 influences hypocotyl and bolting variability via maturation rate, and that smaller barley plants exhibit increased osmotic stress resilience, suggesting ELF3‑driven heterogeneity serves as a bet‑hedging strategy.