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 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.
The study reveals that the microtubule-associated protein MAP70-2 integrates mechanical and biochemical signals to guide division plane orientation during early lateral root primordium formation in Arabidopsis thaliana. Dynamic MAP70-2 localization to cell corners and the cortical division zone precedes cytokinesis, and loss of MAP70-2 results in misoriented divisions and malformed lateral roots, highlighting its role in three‑dimensional differential growth under mechanical constraints.
The study investigated the role of the ABA transporter NPF4.6 in Arabidopsis thaliana by analyzing loss-of-function mutants under steady and fluctuating light. Mutants displayed faster stomatal opening, higher CO2 assimilation, and increased shoot biomass under well‑watered, dynamic‑light conditions, while showing no advantage under drought stress, indicating NPF4.6 fine‑tunes stomatal kinetics in variable light environments.
Authors: Baer, M., Zhong, Y., Yu, B., Tian, T., He, X., Gu, L., Huang, X., Gallina, E., Metzen, I. E., Bucher, M., Song, R., Gutjahr, C., SU, Z., Moya, Y., von Wiren, N., Zhang, L., Yuan, L., Shi, Y., Wang, S., Qi, W., Baer, M., Zhao, Z., Li, C., Li, X., Hochholdinger, F., Yu, P.
The study uncovers how arbuscular mycorrhizal (AM) fungi induce lateral root formation in maize by activating ethylene‑responsive transcription factors (ERFs) that regulate pericycle cell division and reshape flavonoid metabolism, lowering inhibitory flavonols. It also shows that the rhizobacterium Massilia collaborates with AM fungi, degrading flavonoids and supplying auxin, thereby creating an integrated ethylene‑flavonoid‑microbe signaling network that can be harnessed to improve nutrient uptake and crop sustainability.
The study shows that the membrane lipids PI4P, PI(4,5)P2, and phosphatidylserine have distinct spatial and temporal dynamics during lateral root primordium formation in Arabidopsis thaliana, with PI4P acting as a stable basal lipid, PI(4,5)P2 serving as a negative regulator of initiation, and phosphatidylserine increasing after founder cell activation. Using live-cell biosensors, genetic mutants, and an inducible PI(4,5)P2 depletion system, the authors demonstrate that reducing PI(4,5)P2 enhances lateral root initiation and development.
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.
Energy trade-offs under fluctuating light govern bioenergetics and growth in Chlamydomonas reinhardtii
Authors: Pfleger, A., Arc, E., Zhang, S., Chaturvedi, P., Antoine, E., Gnaiger, E., Ghatak, A., Afjehi-Sadat, L., Weckwerth, W., Kranner, I., Roach, T.
The study examined how Chlamydomonas reinhardtii adjusts its metabolism under fluctuating light (FL) compared with constant high or low light, across high and low CO2 conditions. Proteomic and metabolomic analyses revealed that low CO2 drives a carbon‑concentrating mechanism and photorespiration, while high CO2 supports growth by increasing ATP pools and promoting mitochondrial respiration, cyclic electron flow, and starch turnover. The results highlight a CO2‑dependent energy trade‑off between photoprotection, repair, and carbon allocation that governs growth under FL.
The study demonstrates that in the green alga Chlamydomonas reinhardtii, distinct photosynthetic electron flow pathways each operate efficiently over specific light‑fluctuation frequencies, defined as their bandwidths. By systematically varying light periodicities, the authors show that cyclic electron flow handles a broad range, pseudo‑cyclic electron flow supports rapid fluctuations, and chloroplast‑mitochondria electron flow is limited to slower changes, linking these capacities to ATP generation and photoprotection. The findings suggest that cells dynamically adjust the contribution of each pathway according to the frequency of environmental light changes.
PSII photoinhibition as a protective strategy against PSI photoinhibition: Maintaining PSI in an oxidized state by suppressing PSII activity under environmental stress
Authors: Takeuchi, K., Harimoto, S., Maekawa, S., Miyake, C., Ifuku, K.
The study demonstrates that photoinhibition of Photosystem II (PSII) serves as a protective mechanism against Photosystem I (PSI) photoinhibition under chilling stress and fluctuating light, using Arabidopsis thaliana and cucumber. Reduced PSII activity (lower Fv/Fm) kept PSI oxidized and limited ROS production by enhancing re‑oxidation of Fe‑S clusters, confirming PSII‑mediated protection in wild‑type plants.