He Xi, Xu Shouling, Singh Yadav Avilash, Liu Ruoyu, Zhou Heng, Xu Yiru, Xiang Dan, He Yuhan, Xu Juan, Roeder Adrienne H K, Hong Lilan
Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture, Institute of Nuclear Agricultural Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China.
Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture, Institute of Nuclear Agricultural Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; National Key Laboratory for Development and Utilization of Forest Food Resources, Zhejiang A&F University, Hangzhou 311300, China.
Cell Rep. 2025 Jul 22;44(7):115950. doi: 10.1016/j.celrep.2025.115950. Epub 2025 Jul 8.
Flat plant organs are crucial for optimal organ functionality. Polarity establishment and growth coordination between tissues are key factors in maintaining organ flatness. Ectopic ASYMMETRIC LEAVES2 (AS2) expression in the as2-7D mutant has been shown to disrupt growth across cell layers, leading to epidermal buckling in sepals. However, the detailed molecular mechanism remains unclear. Here, we show that mutation of the JAGGED (JAG) gene suppresses buckling of the as2-7D sepal epidermis. Cellular growth analysis reveals that the jag mutant suppresses the sepal epidermal buckling phenotype by altering cellular growth directions to be more parallel with the proximal-distal direction. On the molecular level, JAG physically interacts with AS2. TEOSINTE BRANCHED 1, CYCLOIDEA, AND PCF FAMILY 24 (TCP24) antagonizes JAG in sepal morphogenesis by repressing JAG transcription and inhibiting the AS2-JAG protein interaction. Our study uncovers a complex molecular network involving AS2, JAG, and TCP24 that is critical for generating flat plant organs.
扁平的植物器官对于器官的最佳功能至关重要。组织间的极性建立和生长协调是维持器官扁平的关键因素。在as2 - 7D突变体中异位表达不对称叶片2（ASYMMETRIC LEAVES2，AS2）已被证明会破坏跨细胞层的生长，导致萼片表皮起皱。然而，详细的分子机制仍不清楚。在此，我们表明锯齿状（JAGGED，JAG）基因的突变抑制了as2 - 7D萼片表皮的起皱。细胞生长分析表明，jag突变体通过改变细胞生长方向使其更平行于近端 - 远端方向来抑制萼片表皮起皱表型。在分子水平上，JAG与AS2发生物理相互作用。玉米分枝1、类细胞周期蛋白和PCF家族24（TEOSINTE BRANCHED 1, CYCLOIDEA, AND PCF FAMILY 24，TCP24）在萼片形态发生过程中通过抑制JAG转录并抑制AS2 - JAG蛋白相互作用来拮抗JAG。我们的研究揭示了一个涉及AS2、JAG和TCP24的复杂分子网络，该网络对于形成扁平的植物器官至关重要。
