Leaf morphology varies significantly among Brassica juncea. However, little is known regarding the causal gene that controls lobed leaf shape in B. juncea. In our study, the BjRCO gene, which is associated with leaf morphological variation, was cloned from chromosome A10 in B. juncea via BSR-seq. Blast analysis suggested that the BjRCO encodes a HD-Zip I transcription factor, which may serve as a positive regulator of lobed leaf formation in leaf mustard. Interestingly, the lobed leaf genes reported in the related species of Brassica (B. rapa, B. napus, and B. juncea) were located in A10. Phylogenetic analysis showed that BjRCO was also homologous to the lobed leaf gene BoLl reported on chromosome 9 in B. oleracea. In addition, qRT-PCR results showed that the expression levels of the BjRCO gene were higher expressed in the inner small lobed leaves than in the little sawtooth-like leaves (LSL). These results of this study indicate that the BjRCO gene is related to lobed leaf formation in B. juncea. These findings help to establish a solid foundation for future research investigating the molecular mechanism governing lobed leaf formation in B. juncea.

芥菜叶片形态差异显着。然而，关于控制芥菜中的叶片形状的病因基因知之甚少。在我们的研究中，BjRCO基因与叶片形态变异有关，是通过BSR-seq从芥菜芽孢杆菌A10染色体上克隆的。爆炸分析表明，BjRCO编码HD-Zip I转录因子，可作为芥菜中叶状叶形成的正调节剂。有趣的是，在芸苔属（B. rapa，B。napus和B. juncea）的相关物种中报告了叶片的叶基因）位于A10中。系统发育分析表明，BjRCO也是同源的裂叶基因BOLL中报道9号染色体上甘蓝。此外，qRT-PCR结果表明，内部小叶叶片中的BjRCO基因表达水平高于小锯齿状叶片（LSL）中的表达。这些研究结果表明，BjRCO基因与芥菜叶片叶形成有关。这些发现为进一步研究芥菜裂叶形成的分子机制奠定了坚实的基础。