Evolution of HMA-integrated tandem kinases accompanied by expansion of target pathogens
Authors: Asuke, S., Tagle, A. G., Hyon, G.-S., Koizumi, S., Murakami, T., Horie, A., Niwamoto, D., Katayama, E., Shibata, M., Takahashi, Y., Islam, M. T., Matsuoka, Y., Yamaji, N., Shimizu, M., Terauchi, R., Hisano, H., Sato, K., Tosa, Y.
The study cloned the resistance genes Rmo2 and Rwt7 from barley and wheat, revealing them as orthologous tandem kinase proteins (TKPs) with an N‑terminal heavy metal‑associated (HMA) domain. Domain‑swapping experiments indicated that the HMA domain dictates effector specificity, supporting a model of TKP diversification into paralogs and orthologs that recognize distinct pathogen effectors.
The authors introduce the ENABLE(R) Gene Editing in planta toolkit, a streamlined two‑step cloning system for creating CRISPR/Cas9 knockout vectors suitable for transient or stable transformation. Validation was performed in Oryza sativa protoplasts and Arabidopsis thaliana plants, and the toolkit includes low‑cost protocols aimed at facilitating adoption in the Global South.
The study generated a phenotypic dataset for 550 Lactuca accessions, including 20 wild relatives, and applied an iterative two‑step GWAS using a jointly processed SNP set for cultivated lettuce (L. sativa) and its wild progenitor (L. serriola) to dissect trait loci. Known and novel QTLs for anthocyanin accumulation, leaf morphology, and pathogen resistance were identified, with several L. serriola‑specific QTLs revealing unique genetic architectures, underscoring the breeding value of wild lettuce species.
Large-scale single-cell profiling of stem cells uncovers redundant regulators of shoot development and yield trait variation
Authors: Xu, X., Passalacqua, M., Rice, B., Demesa-Arevalo, E., Kojima, M., Takebayashi, Y., Harris, B., Sakakibara, H., Gallavotti, A., Gillis, J., Jackson, D.
The study finely dissected shoot stem cell–enriched tissues from maize and Arabidopsis thaliana and optimized single‑cell RNA‑seq protocols to reliably capture CLAVATA3 and WUSCHEL‑expressing cells. Cross‑species comparison and functional validation, including spatial transcriptomics and mutant analyses, revealed conserved ribosome‑associated RNA‑binding proteins and sugar‑kinase families as key regulators linked to shoot development and yield traits.
The study introduces Transposase-Accessible Chromosome Conformation Capture (TAC-C), which combines ATAC‑seq and Hi‑C to map fine‑scale chromatin interactions in rice, sorghum, maize, and wheat, revealing genome‑size‑correlated loop structures and distinct C3 vs. C4 patterns. Integration with population genetics shows that loops link distal regulatory elements to phenotypic variation, and SPL transcription factors (TaSPL7/15) modulate photosynthesis‑related genes via these interactions, enhancing photosynthetic efficiency and starch content in wheat mutants.