转录因子GhKNOX1-1调控棉花叶片形态建成的分子机制研究

Leaf is the main place for photosynthesis and nutrients manufacturing, and the shape of leaves directly affects the photosynthetic efficiency and yield of plants. Cotton is an important economic crop and its leaf shape is diverse, but its formation mechanism is still unknown. Through transcriptome sequencing technology and subsequent quantitative PCR methods, GhKNOX1-1 (Knotted-like Homeodomain 1) gene specifically expressed in the lobed leaf was screened from different leaf in cotton. Overexpression of GhKNOX1-1 gene in Arabidopsis resulted in larger leaves and the occurrence of cracking, suggesting that GhKNOX1-1 plays key roles in leaf development. Furthermore, the regulation mechanisms of GhKNOX1-1 gene will be studied by using electrophoretic mobility shift assays (EMSA) and genetics methods. In order to reveal the formation mechanisms of cotton leaves, transgenic technologies combined with high-throughput sequencing are used to study the role of GhKNOX1-1 gene in leaf morphogenesis and related regulatory networks of cotton. The results in this study are important for improving the utilization of light energy and increasing the yield of cotton.

叶片是植物进行光合作用、制造养分的主要场所，叶片的形态影响植物的光合效率和最终产量。棉花是重要的经济作物，其叶片形态多样，但形成机制并不清楚。本课题以棉花裂叶和圆形叶为研究材料，通过转录组测序和定量PCR的方法筛选出与叶片开裂密切相关基因GhKNOX1-1 (Knotted-like Homeodomain 1)，在拟南芥中过表达GhKNOX1-1，导致叶片增大，并发生开裂。上述研究结果表明GhKNOX1-1基因在植物叶片发育过程中具有重要作用。在此基础上，进一步采用凝胶阻滞电泳和遗传学方法研究GhKNOX1-1基因的调控机制；利用转基因技术，结合高通量测序研究GhKNOX1-1调控的下游靶基因及相关信号通路，以阐明GhKNOX1-1基因在棉花叶片形态建成中的作用，揭示棉花叶片形成的规律及分子机制。本研究结果对提高棉花叶片光能利用效率和增加棉花产量具有重要意义。

叶片是植物光合作用的重要器官，具有明显的形态多样性。然而，植物叶片形状变化产生的遗传基础在很大程度上是未知的。在本研究中，我们使用农作物棉花来显示不同叶型的遗传框架。生长素应答因子ARF16-1和I类KNOTTED1同源盒（KNOX）基因KNOX1-1被确定为棉属植物叶片复杂性的关键分子调控因子。深裂叶片中ARF16-1和KNOX1-1转录均显着高于浅裂叶片。GhARF16-1和GhKNOX1-1的过度表达分别导致棉叶有更多和更深的锯齿。GhKNOX1-1是GhARF16-1的上位基因，GhARF16-1直接与GhKNOX1-1启动子中的生长素应答元件（AuxRE）结合以诱导GhKNOX1-1表达。此外，GhARF16-1和GhKNOX1-1的异源表达也导致拟南芥出现裂叶和卷曲的叶片。最终，我们得出的结论：ARF16-KNOX1相互作用模式在双子叶植物中是功能保守的。本研究结果对提高棉花叶片光能利用效率和增加棉花产量具有重要意义。