Evaluation of combined root exudate and rhizosphere microbiota sampling approaches to elucidate plant-soil-microbe interaction
Authors: Escudero-Martinez, C., Browne, E. Y., Schwalm, H., Santangeli, M., Brown, M., Brown, L., Roberts, D. M., Duff, A. M., Morris, J., Hedley, P. E., Thorpe, P., Abbott, J. C., Brennan, F., Bulgarelli, D., George, T. S., Oburger, E.
The study benchmarked several sampling approaches for simultaneous profiling of root exudates and rhizosphere microbiota in soil-grown barley, revealing consistent exudate chemistry across methods but variation in root morphology and nitrogen exudation. High‑throughput amplicon sequencing and quantitative PCR showed protocol‑specific impacts on microbial composition, yet most rhizosphere-enriched microbes were captured by all approaches. The authors conclude that different protocols provide comparable integrated data, though methodological differences must be aligned with experimental objectives.
The study investigates how maternal environmental conditions, specifically temperature and light intensity, influence seed longevity in eight Arabidopsis thaliana natural accessions. Seeds developed under higher temperature (27 °C) and high light showed increased longevity, with transcriptome analysis of the Bor-4 accession revealing dynamic changes in stored mRNAs, including upregulation of antioxidant defenses and raffinose family oligosaccharides. These findings highlight the genotype‑dependent modulation of seed traits by the maternal environment.
The study examined how allelic variation at three barley flowering-time genes (PPD‑H1, ELF3, and PHYC) influences photoperiod response parameters, revealing that ELF3 reduces intrinsic earliness and PhyC‑e lowers photoperiod sensitivity. By testing Near Isogenic Lines and HEB‑25 lines under 16–24 h photoperiods, the authors identified a 20‑h threshold for PPD‑H1 lines and proposed reduced photoperiod regimes (20 h and 16 h) for energy‑efficient speed breeding.
The study investigates the evolutionary shift from archegonial to embryo‑sac reproduction by analyzing transcriptomes of Ginkgo reproductive organs and related species. It reveals that the angiosperm pollen‑tube guidance module MYB98‑CRP‑ECS is active in mature Ginkgo archegonia and that, while egg cell transcription is conserved, changes in the fate of other female gametophyte cells drove the transition, providing a molecular framework for this major reproductive evolution.
The study profiled small interfering RNAs (siRNAs) in barley (Hordeum vulgare) seeds differing in viability after controlled long‑term storage, identifying 85,728 differentially expressed siRNAs associated with seed vigor. Trans‑acting siRNAs displayed distinct temporal patterns during imbibition, and functional analyses linked siRNA targets to key processes such as cytochrome activity, root development, and carbohydrate metabolism, suggesting a role in maintaining metabolic activity during germination.
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.
Post-Domestication selection of MKK3 Shaped Seed Dormancy and End-Use Traits in Barley
Authors: Jorgensen, M. E., Vequaud, D., Wang, Y., Andersen, C. B., Bayer, M., Box, A., Braune, K., Cai, Y., Chen, F., Antonio Cuesta-Seijo, J., Dong, H., Fincher, G. B., Gojkovic, Z., Huang, Z., Jaegle, B., Kale, S. M., Krsticevic, F., Roux, P.-M. L., Lozier, A., Lu, Q., Mascher, M., Murozuka, E., Nakamura, S., Simmelsgaard, M. U., Pedas, P. R., Pin, P., Sato, K., Spannagl, M., Rasmussen, M. W., Russell, J., Schreiber, M., Thomsen, H. C., Tulloch, S., Thomsen, N. W., Voss, C., Skadhauge, B., Stein, N., Waugh, R., Willerslev, E., Dockter, C.
The study demonstrates that in barley (Hordeum vulgare) the MAPK pathway, specifically the MKK3 kinase, controls grain dormancy through a combination of haplotype variation, copy-number changes, and intrinsic kinase activity. Historical selection of particular MKK3 haplotypes correlates with climatic pressures, offering a genetic basis to balance short dormancy with resistance to pre‑harvest sprouting under climate change.
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 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.