The study examined five sequential organ abscission events in two cherry species, revealing that some abscission zones form de novo while others are pre‑formed and reactivated by localized ethylene signaling, leading to cell division, lignification, ROS accumulation, and pH changes. Species‑specific differences were found in petal shedding and a post‑fertilization checkpoint that eliminates small fruits, indicating a hierarchical, multilayered reproductive filter controlling fruit set.
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.
EBSn, a robust synthetic reporter for monitoring ethylene responses in plants
Authors: Fernandez-Moreno, J.-P., Fenech, M., Yaschenko, A. E., Zhao, C., Neubauer, M., Davis, H. N., Marchi, A. J., Concannon, R., Keren-Keiserman, A., Reuveni, M., Levitsky, V. G., Oshchepkov, D., Dolgikh, V., Goldshmidt, A., Ascencio-Ibanez, J. T., Zemlyanskaya, E., Alonso, J. M., Stepanova, A. N.
The authors engineered a novel ethylene‑responsive promoter (EBSn) containing ten divergent natural EIN3‑binding sites and demonstrated that it provides higher sensitivity and broader tissue expression than existing reporters in Arabidopsis thaliana. The EBSn promoter successfully monitored endogenous ethylene levels and also functioned in tomato, suggesting utility for studying ethylene‑regulated processes such as fruit ripening.
The study used quantitative proteomics and co‑fractionation mass spectrometry to uncover rapid ethylene‑induced changes in protein abundance and complex formation during early seedling development, revealing extensive protein multimerization events that correlate with hypocotyl growth modulation. Small‑scale validation confirmed several identified proteins impact hypocotyl development, highlighting novel components of ethylene‑mediated growth regulation.
The study shows that the SnRK1 catalytic subunit KIN10 directs tissue-specific growth‑defense programs in Arabidopsis thaliana by reshaping transcriptomes. kin10 knockout mutants exhibit altered root transcription, reduced root growth, and weakened defense against Pseudomonas syringae, whereas KIN10 overexpression activates shoot defense pathways, increasing ROS and salicylic acid signaling at the cost of growth.
An ERF transcription factor StPTI5, a novel regulator of endophyte community maintenance in potato
Authors: Lukan, T., Kraigher, B., Pogacar, K., Stare, K., Grubar Kovacic, T., Zagorscak, M., Petek, M., Stefanic, P., Vozelj, A., Levak, V., Mahkovec Povalej, T., Garcia, J. M., Pozo, M. J., Mandic-Mulec, I., Gruden, K.
The study shows that the ERF transcription factor PTI5, previously identified as a susceptibility factor, is strongly induced during Bacillus subtilis biofilm establishment on potato roots and modulates ethylene‑dependent immune signaling. Silencing PTI5 enhances bacterial abundance and increases colonization by the arbuscular mycorrhizal fungus Rhizophagus irregularis, indicating PTI5 restricts both pathogenic and beneficial microbial interactions. These findings provide mechanistic insight for managing beneficial plant‑microbe relationships in crops.
The study identifies HISTONE DEACETYLASE COMPLEX 1 (HDC1) as a positive regulator of sepal size during maturation in Arabidopsis thaliana, showing that hdc1 mutants exhibit prolonged elongation due to delayed maturation. Integrated transcriptomic and proteomic analyses, together with genetic and chemical experiments, reveal that HDC1 promotes ethylene production, which in turn triggers ROS accumulation to terminate sepal growth. These findings elucidate a coordinated ethylene‑ROS signaling mechanism controlling organ size during plant development.
The study examined how altering ethylene biosynthesis (ACO1) or perception (etr1.1) in a hybrid poplar (P. tremula × P. tremuloides T89) influences the assembly of root and shoot fungal and bacterial communities, using amplicon sequencing and confocal microscopy. Ethylene modulation had limited impact on the sterile plant metabolome but triggered distinct primary and secondary metabolic changes in microbe‑colonized plants, correlating with reduced fungal colonisation of shoots and increased root fungal colonisation, while arbuscular mycorrhizal fungi and bacterial communities were largely unchanged.
The study reveals that programmed cell death (PCD) drives hollow stem formation in water spinach (Ipomoea aquatica), regulated by ethylene and reactive oxygen species (ROS) through specific transcription factors. Single‑cell transcriptomics and functional assays, including ethylene/ROS treatments and transient expression in tobacco, confirm the role of these pathways, which appear conserved in bamboo.
Ethylene modulates cell wall mechanics for root responses to compaction
Authors: Zhang, J., Qu, Z., Liu, Z., Li, J., Farrar, E., Chara, O., Ogorek, L. P., Borges, A., Sakamoto, S., Mitsuda, N., Zhu, X., Zhu, M., Shi, J., Liang, W., Bennett, M., Pandey, B., Zhang, D., Persson, S.
The study shows that soil compaction induces ethylene production, which upregulates Auxin Response Factor1 in the root cortex and represses cellulose synthase genes, leading to altered cell wall thickness and mechanics that cause radial expansion of cortical cells. This ethylene‑mediated modulation of cell wall strength creates a stiff epidermis‑soft cortex architecture, linking hormonal signaling to root mechanical adaptation in compacted soils.