Shanghai Botanical Garden, No. 1111 Longwu Road, Shanghai 200231, People's Republic of China.
Plant Physiol Biochem. 2013 Sep;70:483-91. doi: 10.1016/j.plaphy.2013.06.013. Epub 2013 Jun 27.
The cell wall plays crucial roles in establishing the morphology of the plant cell, defence response to biotic and abiotic stresses, and mechanical properties of organs. The COBRA gene encodes a putative glycosylphosphatidylinositol (GPI)-anchored protein that possesses the ability to modulate cellulose deposition and orient cell expansion in plant cell. We reported here the functional characterization of ClCOBL1, a conifer COBRA-like gene from the differentiating xylem of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook). ClCOBL1 belonged to a woody plant-specific clade of the COBRA protein family with several conserved motifs. Expression pattern demonstrated that ClCOBL1 was constitutively expressed but with high level in cambium region. ClCOBL1 protein was mainly located in the cell wall and plasma membrane. Overexpression of ClCOBL1 in tobacco plants yielded altered leaf adaxial-abaxial patterning and short, swollen corolla tubes. The changed leaf architecture in the ClCOBL1 overexpressors was associated with the differential expression of leaf adaxial-abaxial identity genes. Our results indicated that ClCOBL1 was involved in the determination of leaf dorsoventrality and anisotropic expansion possibly by affecting the expression of adaxial and abaxial identity genes.
细胞壁在建立植物细胞的形态、对生物和非生物胁迫的防御反应以及器官的机械性能方面起着至关重要的作用。COBRA 基因编码一种假定的糖基磷脂酰肌醇（GPI）锚定蛋白，具有调节植物细胞中纤维素沉积和定向细胞扩展的能力。我们在这里报道了 ClCOBL1 的功能特征，ClCOBL1 是来自中国冷杉（Cunninghamia lanceolata（Lamb.）Hook）分化木质部的针叶树 COBRA 样基因。ClCOBL1 属于 COBRA 蛋白家族的木质植物特异性分支，具有几个保守基序。表达模式表明，ClCOBL1 持续表达，但在形成层区域表达水平较高。ClCOBL1 蛋白主要位于细胞壁和质膜中。在烟草植物中过表达 ClCOBL1 导致叶片腹背模式发生改变和花冠状管短而肿胀。ClCOBL1 过表达植株的叶片结构变化与叶片腹背身份基因的差异表达有关。我们的结果表明，ClCOBL1 可能通过影响腹背身份基因的表达，参与叶片背腹侧方向和各向异性扩展的决定。
