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 study demonstrates that a beta‑1,3‑glucan‑binding protein from the rice blast fungus Magnaporthe oryzae interacts with the rice thaumatin‑like protein OsPR5, which sequesters the fungal protein to trigger immunity, while the fungus secretes thaumatin‑binding proteins to counteract this defense. Additionally, a rice cell‑surface receptor kinase containing a thaumatin domain has evolved to detect the fungal GBP, highlighting a complex coevolutionary arms race in the rice apoplast.
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.
Comparative multi-omics profiling of Gossypium hirsutum and Gossypium barbadense fibers at high temporal resolution reveals key differences in polysaccharide composition and associated glycosyltransferases
Authors: Swaminathan, S., Lee, Y., Grover, C. E., DeTemple, M. F., Mugisha, A. S., Sichterman, L. E., Yang, P., Xie, J., Wendel, J. F., Szymanski, D. B., Zabotina, O. A.
The study performed daily large-scale glycome, transcriptome, and proteome profiling of developing fibers from the two cultivated cotton species, Gossypium barbadense and G. hirsutum, across primary and secondary cell wall stages. It identified delayed cellulose accumulation and distinct compositions of xyloglucans, homogalacturonans, rhamnogalacturonan‑I, and heteroxylans in G. barbadense, along with higher expression of specific glycosyltransferases and expansins, suggesting these molecular differences underlie the superior fiber length and strength of G. barbadense.
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.