Winkelmolen Ton, Colleoni Pierangela, Moscou Matthew J, Hoseinzadeh Parastoo, Oldach Klaus, Schmidt Ralf Christian, Immink Richard G H, van Esse G Wilma
Laboratory of Molecular Biology, Wageningen University and Research, Wageningen 6708 PB, The Netherlands.
The Sainsbury Laboratory, Norwich Research Park, Norwich NR47 UH, UK.
Plant Physiol. 2025 Aug 4;198(4). doi: 10.1093/plphys/kiaf309.
Variation in shoot architecture, or tillering, is an important adaptive trait targeted during the domestication of crops. A well-known regulatory factor in shoot architecture is TEOSINTE BRANCHED 1 (TB1). TB1 and its orthologs have a conserved function in integrating environmental signals to regulate axillary branching or tillering in cereals. The barley (Hordeum vulgare) ortholog of TB1, VULGARE ROW-TYPE SIX 5 (VRS5), regulates tillering and is involved in regulating row-type by inhibiting lateral spikelet development. These discoveries predominantly come from genetic studies; however, how VRS5 regulates these processes on a molecular level remains largely unknown. By combining transcriptome analysis between the vrs5 mutant and the wild-type at different developmental stages and DAP-sequencing to locate the genome-wide DNA binding sites of VRS5, we identified bona fide targets of VRS5. We found that VRS5 targets abscisic acid-related genes, potentially to inhibit tillering in a conserved way. Later in inflorescence development, VRS5 also targets row-type gene VRS1 and several known floral development genes, such as MIKCc-type MADS-box genes. This study identifies several genes for mutational analysis, representing a selection of bona fide targets that will contribute to a deeper understanding of the VRS5 network and its role in shaping barley development.
地上部株型变异，即分蘖，是作物驯化过程中的一个重要适应性性状。地上部株型中一个著名的调控因子是玉米分枝1（TB1）。TB1及其直系同源基因在整合环境信号以调节谷类作物的腋芽分枝或分蘖方面具有保守功能。TB1的大麦（Hordeum vulgare）直系同源基因，即大麦行型六5（VRS5），调控分蘖，并通过抑制侧小穗发育参与行型调控。这些发现主要来自遗传学研究；然而，VRS5如何在分子水平上调控这些过程在很大程度上仍不清楚。通过结合vrs5突变体和野生型在不同发育阶段的转录组分析以及DAP测序来定位VRS5在全基因组范围内的DNA结合位点，我们鉴定出了VRS5的真正靶标。我们发现VRS5靶向脱落酸相关基因，可能以一种保守的方式抑制分蘖。在花序发育后期，VRS5还靶向行型基因VRS1和几个已知的花发育基因，如MIKCc型MADS盒基因。本研究鉴定出了几个用于突变分析的基因，代表了一系列真正的靶标，这将有助于更深入地理解VRS5网络及其在塑造大麦发育中的作用。
