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 demonstrates that plasmodesmata‑located protein 5 (PDLP5) interacts with plasma membrane intrinsic proteins (PIPs) to inhibit H2O2 transport across the plasma membrane in Arabidopsis. Overexpression of PDLP5 reduces H2O2 uptake and diminishes H2O2‑induced root growth inhibition, whereas pdlp5 mutants show enhanced sensitivity, with PIP2;5 identified as a key target of this regulation.
Phosphite (Phi) and phosphate (Pi) share the same root uptake system, but Phi acts as a biostimulant that modulates plant growth and disease resistance in a species‑ and Pi‑dependent manner. In Arabidopsis, Phi induces hypersensitive‑like cell death and enhances resistance to Plectosphaerella cucumerina, while in rice it counteracts Pi‑induced susceptibility to Magnaporthe oryzae and Fusarium fujikuroi, accompanied by extensive transcriptional reprogramming.
The study used live-cell fluorescence imaging of Arabidopsis thaliana pollen tubes co-expressing labeled tubulin and actin to reveal partial co-localization of the two cytoskeletal networks. Pharmacological disruption showed that microtubules depend on actin for stability in the medial region, while actin remains unaffected by microtubule loss, indicating spatially dependent cytoskeletal crosstalk. Tracking of the microtubule plus‑end binding protein EB1b demonstrated that the microtubule array is primarily parallel with plus ends oriented away from the apex.
The study demonstrates that invasion of Arabidopsis thaliana roots by the parasitic plant Phtheirospermum japonicum induces a phosphate‑starvation response in the host, which in turn leads to systemic suppression of immunity. This immunosuppression makes Arabidopsis more vulnerable to secondary microbial infections, highlighting the importance of multitrophic interactions in crop resilience.
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.
The circadian clock gates lateral root development
Authors: Nomoto, S., Mamerto, A., Ueno, S., Maeda, A. E., Kimura, S., Mase, K., Kato, A., Suzuki, T., Inagaki, S., Sakaoka, S., Nakamichi, N., Michael, T. P., Tsukagoshi, H.
The study identifies the circadian clock component ELF3 as a temporal gatekeeper that limits hormone‑induced pericycle proliferation and lateral root development in Arabidopsis thaliana. Time‑resolved transcriptomics, imaging, and genetic analyses show that ELF3 maintains rhythmic expression of key regulators via LNK1 and MADS‑box genes, and that loss of ELF3 disrupts this rhythm, enhancing callus growth and accelerating root organogenesis.
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.
The study created a system that blocks root‑mediated signaling between wheat varieties in a varietal mixture and used transcriptomic and metabolomic profiling to reveal that root chemical interactions drive reduced susceptibility to Septoria tritici blotch, with phenolic compounds emerging as key mediators. Disruption of these root signals eliminates both the disease resistance phenotype and the associated molecular reprogramming.
The study demonstrates that cytokinin (CK) signaling strength is governed by the interplay of receptor preference and metabolic stability of individual CK isoforms, affecting tissue-specific responses in Arabidopsis. Using physiological, genetic, and multi-omics approaches, the authors show that dihydrozeatin compensates for lower receptor affinity with higher persistence during senescence, while N‑glucoside CKs modulate signaling intensity in a ratio‑dependent manner.