Szymanski D B, Marks M D
Department of Genetics and Cell Biology, University of Minnesota, 1445 Gortner Avenue, St. Paul, Minnesota 55108-1095, USA.
Plant Cell. 1998 Dec;10(12):2047-62. doi: 10.1105/tpc.10.12.2047.
Cellular competence, initiation cues, and inhibition signals control the distribution of trichomes on the Arabidopsis leaf. The GLABROUS1 (GL1) gene has a dual role in that it is required for trichome initiation, but GL1 overexpression reduces trichome number. We have found that a mutation in the TRIPTYCHON (TRY) gene partially suppresses the GL1 overexpression phenotype but not in a way that indicates that TRY directly controls an epidermal inhibition pathway. Surprisingly, cauliflower mosaic virus 35S::GL1 try plants contain a subclass of trichomes derived from the subepidermal layer. Altered cell cycle control was also detected in 35S::GL1 and try plants. A mutation in TRY led to increased epidermal and mesophyll cell number, a reduction in endoreduplication in the epidermis, and an increase in endoreduplication in trichomes. GL1 overexpression also reduced endoreduplication levels in both the epidermis and trichomes; however, in the presence of try, it synergistically enhanced trichome endoreduplication. Interactions with the COTYLEDON TRICHOME1 (COT1) gene indicate that GL1 and TRY control trichome development and may be involved in cell cycle control during leaf development.
细胞感受态、起始信号和抑制信号控制着拟南芥叶片上毛状体的分布。GLABROUS1（GL1）基因具有双重作用，它是毛状体起始所必需的，但GL1过表达会减少毛状体数量。我们发现，TRIPTYCHON（TRY）基因的突变部分抑制了GL1过表达表型，但并非以表明TRY直接控制表皮抑制途径的方式。令人惊讶的是，花椰菜花叶病毒35S::GL1 try植株含有一类源自表皮下细胞层的毛状体。在35S::GL1和try植株中也检测到细胞周期控制的改变。TRY基因突变导致表皮和叶肉细胞数量增加，表皮内复制减少，毛状体内复制增加。GL1过表达也降低了表皮和毛状体内的内复制水平；然而，在try存在的情况下，它协同增强了毛状体内复制。与子叶毛状体1（COT1）基因的相互作用表明，GL1和TRY控制毛状体发育，并且可能参与叶片发育过程中的细胞周期控制。
