Tavakol Elahe, Shariati Vahid, Fontana Irene Maria, Binaghi Marta, Stellmach Hagen, Hause Bettina, Bethke Gerit, Bilgic Hatice, Boddu Jayanand, Okagaki Ron, Heinen Shane, Muehlbauer Gary J, Rossini Laura
Department of Plant Genetics and Production, Shiraz University, Shiraz, Iran.
Department of Molecular Biotechnology, National institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran.
J Exp Bot. 2025 May 27;76(8):2177-2191. doi: 10.1093/jxb/eraf068.
Plant architecture is a key determinant of crop yield, and understanding the genetic basis of its regulation is crucial for crop improvement. BLADE-ON-PETIOLE (BOP) genes are known to play a fundamental role in shaping plant architecture across diverse species. In this study, we demonstrate pleiotropic effects of the barley BOP gene Uniculme4 (Cul4) on various aspects of plant architecture, including plant height, culm diameter, and grain traits. Accordingly, Cul4 is broadly expressed in different tissues and developmental stages. Comparing transcriptome profiles of cul4 mutant and wild-type plants, we uncover a novel link between Cul4 and the jasmonic acid (JA) biosynthetic pathway. Our findings demonstrate that proper Cul4 function is required to repress JA biosynthesis, with cul4 mutants exhibiting increased levels of JA and its precursor 12-oxo-phytodienoic acid. Up-regulation of WRKY and bHLH transcription factors shows JA signalling is also impacted by Cul4. Additionally, our study sheds light on the role of Cul4 in flowering time regulation, potentially through its interaction with florigen-like genes. This research enhances our understanding of the mechanisms and pathways acting downstream of BOP genes.
株型是作物产量的关键决定因素，了解其调控的遗传基础对于作物改良至关重要。已知叶片着生在叶柄上（BOP）基因在塑造不同物种的株型方面发挥着重要作用。在本研究中，我们证明了大麦BOP基因单茎4（Cul4）对株型的多个方面具有多效性影响，包括株高、茎直径和籽粒性状。相应地，Cul4在不同组织和发育阶段广泛表达。通过比较cul4突变体和野生型植物的转录组图谱，我们发现了Cul4与茉莉酸（JA）生物合成途径之间的新联系。我们的研究结果表明，需要适当的Cul4功能来抑制JA生物合成，cul4突变体表现出JA及其前体12-氧代-植物二烯酸水平升高。WRKY和bHLH转录因子的上调表明JA信号传导也受到Cul4的影响。此外，我们的研究揭示了Cul4在开花时间调控中的作用，可能是通过其与类成花素基因的相互作用。这项研究增进了我们对BOP基因下游作用机制和途径的理解。
