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.
Mutations in the plastid division gene PARC6 and the granule initiation gene BGC1 were combined to generate wheat plants with dramatically enlarged A-type starch granules, some exceeding 50 µm, without affecting plant growth, grain size, or overall starch content. The parc6 bgc1 double mutant was evaluated in both glasshouse and field trials, and the giant granules displayed altered viscosity and pasting temperature, offering novel functional properties for food and industrial applications.
A SABATH family enzyme regulates development via the gibberellin-related pathway in the liverwort Marchantia polymorpha
Authors: Kawamura, S., Shimokawa, E., Ito, M., Nakamura, I., Kanazawa, T., Iwano, M., Sun, R., Yoshitake, Y., Yamaoka, S., Yamaguchi, S., Ueda, T., Kato, M., Kohchi, T.
The study identified 12 SABATH methyltransferase genes in the liverwort Marchantia polymorpha and demonstrated that MpSABATH2 is crucial for normal thallus growth and gemma cup formation. Loss‑of‑function mutants displayed developmental phenotypes reminiscent of far‑red light responses, which were linked to gibberellin metabolism and could be partially rescued by inhibiting GA biosynthesis or supplying the GA precursor ent‑kaurenoic acid. These findings suggest that SABATH enzymes independently evolved regulatory roles in land‑plant development.
The study demonstrates that carbon availability promotes gemma cup formation in Marchantia polymorpha by activating cytokinin signaling, which up‑regulates the transcription factors MpGCAM1 and MpSTG. Pharmacological and genetic manipulations showed that cytokinin accumulation in response to sucrose and high light is sufficient to overcome low‑sucrose repression, and that this pathway operates independently of KAI2A‑MAX2 mediated karrikin signaling. The findings suggest a conserved carbon‑cytokinin interaction governing developmental plasticity across land plants.
A comprehensive multi‑environment trial of 437 maize testcross hybrids derived from 38 MLN‑tolerant lines and 29 testers identified additive genetic effects as the primary driver of grain yield, disease resistance, and drought tolerance. Strong general combining ability and specific combining ability patterns were uncovered, with top hybrids delivering up to 5.75 t ha⁻¹ under MLN pressure while maintaining high performance under optimum and drought conditions. The study provides a framework for selecting elite parents and exploiting both additive and non‑additive effects to develop resilient maize hybrids for sub‑Saharan Africa.
Glycosylated diterpenes associate with early containment of Fusarium culmorum infection across wheat (Triticum aestivum L.) genotypes under field conditions
Authors: Pieczonka, S. A., Dick, F., Bentele, M., Ramgraber, L., Prey, L., Kupczyk, E., Seidl-Schulz, J., Hanemann, A., Noack, P. O., Asam, S., Schmitt-Kopplin, P., Rychlik, M.
The researchers performed a large‑scale field trial with 105 wheat (Triticum aestivum) genotypes inoculated by Fusarium culmorum, combining quantitative deoxynivalenol (DON) profiling and untargeted metabolomics to uncover molecular signatures of infection. Sesquiterpene‑derived metabolites tracked toxin accumulation, whereas glycosylated diterpene conjugates were enriched in low‑DON samples, indicating a potential defensive metabolic pathway.
The study characterizes the liverwort-specific NPR protein (MpNPR) in Marchantia polymorpha, demonstrating that it controls oil body formation and confers resistance to gastropod herbivory through interaction with the transcription factor MpERF13. Loss- or gain-of-function of MpNPR disrupts MpERF13‑dependent gene expression and compromises defense against snail feeding, revealing a lineage‑specific immune pathway distinct from tracheophyte NPR functions.
The study performed a meta‑transcriptomic analysis of over twenty drought versus control experiments in Vitis vinifera and two hybrid rootstocks, identifying a core set of 4,617 drought‑responsive genes. Using transcription factor binding motif enrichment and random‑forest machine learning, gene regulatory networks were built, revealing key regulators such as ABF2, MYB30A, and a novel HMG‑box protein. These regulators and network hierarchies provide candidate targets for breeding and biotechnological improvement of grapevine drought tolerance.
Thermotolerant pollen tube growth is controlled by RALF signaling.
Authors: Althiab Almasaud, R., Ouonkap Yimga, S. V., Ingram, J., Oseguera, Y., Alkassem Alosman, M., Travis, C., Henry, A., Medina, M., Oulhen, N., Wessel, G. M., Delong, A., Pease, J., DaSilva, N., Johnson, M.
The study investigates the molecular basis of heat‑tolerant pollen tube growth in tomato (Solanum lycopersicum) by comparing thermotolerant and sensitive cultivars. Using live imaging, transcriptomics, proteomics, and genetics, the authors identified the Rapid Alkalinization Factor (RALF) signaling pathway as a key regulator of pollen tube integrity under high temperature, with loss of a specific RALF peptide enhancing tube integrity in a thermotolerant cultivar.
The study demonstrates that red and blue light have opposing effects on thallus growth orientation in Marchantia polymorpha, with red light promoting epinasty and blue light promoting hyponasty. Loss-of-function mutants in the respective photoreceptors and BBX transcription factors reveal antagonistic interactions that balance thallus flatness under white light. Time‑resolved transcriptomics identified rapid light‑induced genes, including all six MpBBX members, whose mutant phenotypes support this antagonistic model.