The study integrates genome, transcriptome, and chromatin accessibility data from 380 soybean accessions to dissect the genetic and regulatory basis of symbiotic nitrogen fixation (SNF). Using GWAS, TWAS, eQTL mapping, and ATAC-seq, the authors identify key loci, co‑expression modules, and regulatory elements, and validate the circadian clock gene GmLHY1b as a negative regulator of nodulation via CRISPR and CUT&Tag. These resources illuminate SNF networks and provide a foundation for soybean improvement.
The study introduced a novel method to quantify abscission zone competency (AZC) and examined physiological traits across four temperate tree species with differing leaf habits. Results revealed divergent timing between chlorophyll loss, photosynthetic decline, and AZC development, highlighting that senescence and abscission are separate, variably timed processes among deciduous, brevi‑deciduous, and marcescent trees.
MdBRC1 and MdFT2 Interaction Fine-Tunes Bud Break Regulation in Apple
Authors: Gioppato, H. A., Estevan, J., Al Bolbol, M., Soriano, A., Garighan, J., Jeong, K., Georget, C., Soto, D. G., El Khoury, S., Falavigna, V. d. S., George, S., Perales, M., Andres, F.
The study identifies the transcription factor MdBRC1 as a key inhibitor of bud growth during the ecodormancy phase in apple (Malus domestica), directly regulating dormancy‑associated genes and interacting with the flowering promoter MdFT2 to modulate bud break. Comparative transcriptomic analysis and gain‑of‑function experiments in poplar demonstrate that MdFT2 physically binds MdBRC1, attenuating its repressive activity and acting as a molecular switch for the transition to active growth.
The study introduced full-length SOC1 genes from maize and soybean, and a partial SOC1 gene from blueberry, into tomato plants under constitutive promoters. While VcSOC1K and ZmSOC1 accelerated flowering, all three transgenes increased fruit number per plant mainly by promoting branching, and transcriptomic profiling revealed alterations in flowering, growth, and stress‑response pathways.
SnRK2.4 and SnRK2.10 redundantly control developmental leaf senescence by sustaining ABA production and signaling
Authors: Anielska-Mazur, A., Rachowka, J., Polkowska-Kowalczyk, L., Krzyszton, M., Cieslak, D., Mazur, R., Bucholc, M., Rakowska, J., Trzmiel, D., Stachula, P., Olechowski, M., Swiezewski, S., Dobrowolska, G., Kulik, A.
The study reveals that the Arabidopsis SnRK2.4 and SnRK2.10 kinases, previously known for stress responses, are activated during normal developmental leaf senescence and act redundantly to promote this process. They stimulate ABA accumulation by up‑regulating NCED2 and modulate expression of ABA‑responsive and senescence genes, while also enhancing MAPKKK18 expression and activity, linking SnRK2 signaling to MAPK pathways.
The study generated a temporal physiological and metabolomic map of leaf senescence in diverse maize inbred lines differing in stay‑green phenotype, identifying 84 metabolites associated with senescence and distinct metabolic signatures between stay‑green and non‑stay‑green lines. Integration of metabolite data with genomic information uncovered 56 candidate genes, and reverse‑genetic validation in maize and Arabidopsis demonstrated conserved roles for phenylpropanoids such as naringenin chalcone and eriodictyol in regulating senescence.