The shape of the leaf is the primary phenotype which determines the commercial value of leaf mustard (Brassica juncea). However, there arefew reports on the lobed-leaf gene of B. juncea, and the molecular regulatory mechanisms underlying leaf margin formation are unknown. In this study, an F₂ population derived from ‘MN001’ and ‘MU056’ was constructed. Genetic analysis revealed that the lobed-leaf trait is controlled by a major gene, and lobed leavesare dominant compared to round leaves. The GradedPool-Seq analysis combined with the re-sequencing results of parents identified a major interval on chromosome 10 of B. juncea’s genome A. The BjLMI1 gene (BjuA040054) was confirmed to be a candidate gene by gene ontology (GO) analysis, and it is homologous with LMI1 and encodes HD-Zip protein ATHB-51. A base substitution was observed in the conserved domain, and a 63 bp fragment deletion was found in the exon region between the two parents in the CDs region. The expression of BjLMI1 was significantly higher in the lobed-leaf parent than in the round-leaf parent. These findings provide insights into the molecular mechanism underlying leaf margin formation and will be valuable in the development of an ideal leaf shape in B. juncea.

中文翻译：

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芥菜叶表型与 BjLMI1 基因座相关，使用 GradedPool-Seq 证明

叶子的形状是决定芥菜（芥菜）商业价值的主要表型。然而，关于芥菜分叶基因的报道较少，叶缘形成的分子调控机制尚不清楚。在这项研究中，构建了来自“MN001”和“MU056”的 F _2种群。遗传分析表明，裂叶性状由一个主要基因控制，与圆叶相比，裂叶占优势。GradedPool-Seq 分析结合父母的重测序结果确定了芥菜基因组 A. BjLMI1基因 ( BjuA040054 ) 的 10 号染色体上的一个主要区间)经基因本体(GO)分析证实为候选基因，与LMI1同源，编码HD-Zip蛋白ATHB-51。在保守结构域中观察到碱基替换，并且在 CDs 区域中两个亲本之间的外显子区域发现了一个 63 bp 的片段缺失。BjLMI1在裂叶亲本中的表达显着高于圆叶亲本。这些发现提供了对叶缘形成的分子机制的深入了解，并且对于在芥菜中开发理想的叶形具有重要价值。