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 used chlorophyll fluorescence imaging to map non-photochemical quenching (NPQ) gradients along barley leaf axes and found heat stress attenuates NPQ induction, revealing spatial heterogeneity in stress responses. Genome‑wide association and transcriptomic analyses identified candidate genes, notably HORVU.MOREX.r3.3HG0262630, that mediate region‑specific heat responses, highlighting pathways for improving cereal heat resilience.
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.
A comparative physiological study of persimmon cultivars with flat (Hiratanenashi) and round (Koushimaru) fruit shapes revealed that differences in cell proliferation, cell shape, and size contribute to shape variation. Principal component analysis of elliptic Fourier descriptors tracked shape changes, while histology and transcriptome profiling identified candidate genes, including a WOX13 homeobox gene, potentially governing fruit shape development.
The study applied Spatial Analysis of Field Trials with Splines (SpATS) and Neighbor Genome-Wide Association Study (Neighbor GWAS) to barley field data, revealing that neighboring genotypes contribute to spatial variation in disease damage. Neighbor GWAS identified variants on chromosome 7H that modestly affect net form net blotch and scald resistance, suggesting that genotype mixtures could mitigate pest damage.
The study evaluated natural genetic variation in non-photochemical quenching and photoprotection across 861 sorghum accessions grown in the field over two years, revealing moderate to high broad-sense heritability for chlorophyll fluorescence traits. By integrating genome-wide association studies (GWAS) with transcriptome-wide association studies (TWAS) and covariance analyses, the authors identified 110 high-confidence candidate genes underlying photoprotection, highlighting a complex, polygenic architecture for these traits.
Ethylene and ROS Signaling Are Key Regulators of Lateral Root Development under Salt Stress in Tomato
Authors: Rahmati Ishka, M., Zhao, J., Sussman, H., Mohanty, D., Craft, E., Yu, L., Pineros, M., Tester, M., Kawa, D., Mittler, R., Nelson, A., Fei, Z., Julkowska, M. M.
The study examined salt-induced alterations in root system architecture across a diverse panel of wild and cultivated tomato accessions, identifying tolerant varieties with distinct lateral root strategies. By combining Bulk Segregant Analysis of an F2 population with GWAS, the authors pinpointed 22 candidate genes, further narrowing to two key regulators through RNA‑Seq and functional assays involving ethylene and ROS profiling. These findings reveal genetic targets for improving salt resilience in tomato root development.
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 investigates the role of the Arabidopsis transcription factor AtMYB93 in sulfur (S) signaling and root development, revealing that AtMYB93 mutants exhibit altered expression of S transport and metabolism genes and increased shoot S levels, while tomato plants overexpressing SlMYB93 show reduced shoot S. Transcriptomic profiling, elemental analysis, and promoter activity assays indicate that AtMYB93 contributes to root responses to S deprivation, though functional redundancy masks clear phenotypic effects on lateral and adventitious root formation.
The study examined how genetic variation among 181 wheat (Triticum aestivum) lines influences root endophytic fungal communities using ITS2 metabarcoding. Heritability estimates and GWAS identified 11 QTLs linked to fungal clade composition, highlighting genetic control of mycobiota, especially for biotrophic AMF. These findings suggest breeding can be used to modulate beneficial root-fungal associations.