Regulation of planar growth by the Arabidopsis AGC protein kinase UNICORN
Regulation of planar growth by the Arabidopsis AGC protein kinase UNICORN
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DOI：
10.1073/pnas.1205089109
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发表时间：
2012-09-11
影响因子：
11.1
通讯作者：
Schneitz, Kay
中科院分区：
文献类型：
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作者：
Enugutti, Balaji;Kirchhelle, Charlotte;Schneitz, Kay
植物生长的空间协调性对植物组织结构的调控具有重要意义。个别层，如表皮，通过沿该层平面定向的对称细胞分裂进行克隆繁殖和结构维持。对这一过程的发育控制知之甚少。拟南芥珠被的简单细胞基础和片状结构使其成为解决平面生长问题的一个有吸引力的模型系统。在此，我们报道了拟南芥独角兽(UCN)基因的特征。对UCN被片的分析显示平面生长的局部性扭曲，最终导致异位多细胞突起。此外，UCN突变体在花丝和花瓣中表现出异位生长，以及异常的胚胎发生。我们进一步证明了UCN编码一个活性的AGC VIII激酶。遗传、生化和细胞生物学数据表明，UCN通过直接抑制Kanadi转录因子异常的种皮形状来抑制珠被的异位生长。我们的发现表明，UCN是一种独特的植物生长调节剂，它通过抑制参与控制早期珠被生长和极性的发育调节器来维持珠被的平面生长。
The spatial coordination of growth is of central importance for the regulation of plant tissue architecture. Individual layers, such as the epidermis, are clonally propagated and structurally maintained by symmetric cell divisions that are oriented along the plane of the layer. The developmental control of this process is poorly understood. The simple cellular basis and sheet-like structure of Arabidopsis integuments make them an attractive model system to address planar growth. Here we report on the characterization of the Arabidopsis UNICORN (UCN) gene. Analysis of ucn integuments reveals localized distortion of planar growth, eventually resulting in an ectopic multicellular protrusion. In addition, ucn mutants exhibit ectopic growth in filaments and petals, as well as aberrant embryogenesis. We further show that UCN encodes an active AGC VIII kinase. Genetic, biochemical, and cell biological data suggest that UCN suppresses ectopic growth in integuments by directly repressing the KANADI transcription factor ABERRANT TESTA SHAPE. Our findings indicate that UCN represents a unique plant growth regulator that maintains planar growth of integuments by repressing a developmental regulator involved in the control of early integument growth and polarity.