Photoperiod-mediated flowering determines the phenological adaptability of crops including soybean (Glycine max). A genome-wide association study (GWAS) identified a new flowering time locus, Time of flowering 13 (Tof13), which defined a gene encoding an AP2/ERF transcription factor. This new transcription factor, which we named TOE4b, is localized in the nucleus. TOE4b has been selected for soybean latitude adaptability. The existing natural variant TOE4b^H4 was rare in wild soybean accessions but occurred more frequently in landraces and cultivars. Notably, TOE4b^H4 improved high-latitude adaptation of soybean to some extent. The gene-edited TOE4b knockout mutant exhibited earlier flowering, conversely, TOE4b overexpression delayed flowering time. TOE4b is directly bound to the promoters and gene bodies of the key flowering integration factor genes FT2a and FT5a to inhibit their transcription. Importantly, TOE4b overexpression lines in field trials not only showed late flowering but also altered plant architecture, including shorter internode length, more internodes, more branches and pod number per plant, and finally boosted grain yield per plant by 60% in Guangzhou and 87% in Shijiazhuang. Our findings therefore identified TOE4b as a pleiotropic gene to increase yield potential per plant in soybean, and these results provide a promising option for breeding a soybean variety with an idealized plant architecture that promotes high yields.

中文翻译：

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AP2/ERF转录因子TOE4b调节大豆光周期开花和单株籽粒产量

光周期介导的开花决定了包括大豆 ( Glycine max )在内的作物的物候适应性。一项全基因组关联研究 (GWAS) 确定了一个新的开花时间基因座，即开花时间 13 ( Tof13 )，它定义了编码 AP2/ERF 转录因子的基因。这种新的转录因子，我们命名为 TOE4b，位于细胞核中。TOE4b已被选择用于大豆纬度适应性。现有的天然变体TOE4b ^H4在野生大豆种质中很少见，但在地方品种和栽培品种中更常见。值得注意的是，TOE4b ^H4在一定程度上改善了大豆的高纬度适应性。基因编辑的TOE4b敲除突变体表现出更早的开花时间，相反，TOE4b过表达则延迟了开花时间。TOE4b直接与关键开花整合因子基因FT2a和FT5a的启动子和基因体结合，抑制其转录。重要的是，田间试验中TOE4b过表达株系不仅表现出晚花，而且还改变了植株结构，包括节间长度更短、节间更多、每株分枝和荚数更多，最终使广州单株籽粒产量提高了60%，提高了87%在石家庄。因此，我们的研究结果确定TOE4b是一种多效性基因，可以提高大豆单株产量潜力，这些结果为培育具有理想植物结构、促进高产的大豆品种提供了一个有前景的选择。