Franks Robert G, Liu Zhongchi, Fischer Robert L
Department of Genetics, North Carolina State University, Raleigh, NC 27695, USA.
Planta. 2006 Sep;224(4):801-11. doi: 10.1007/s00425-006-0264-6. Epub 2006 Apr 20.
Unlike in animals where cell migrations and programmed cell death play key roles in organ shape determination, in plants organ shape is largely a result of coordinated cellular growth (cell divisions and cell elongations). We have investigated the role of the SEUSS and LEUNIG genes in Arabidopsis thaliana (L.) Heynh. petal development to better understand the molecular mechanisms through which cellular growth and organ shape are coordinated in plants. SEUSS and LEUNIG encode components of a putative transcriptional regulatory complex that controls organ identity specification through the repression of the floral organ identity gene AGAMOUS. SEUSS and LEUNIG also regulate petal shape through AGAMOUS-independent mechanisms; however, the molecular and cellular actions of SEUSS and LEUNIG during petal development are unknown. Here we show that SEUSS and LEUNIG control blade cell number and vasculature development within the petal. Furthermore, SEUSS and LEUNIG regulate petal polarity along the adaxial/abaxial axis. We present a model where SEUSS and LEUNIG are required to potentiate the key polarity genes PHABULOSA and FILAMENTOUS FLOWER/YABBY1 and thus influence cellular growth within the developing petal blade.
与动物不同，在动物中细胞迁移和程序性细胞死亡在器官形态决定中起关键作用，而在植物中，器官形态很大程度上是细胞协调生长（细胞分裂和细胞伸长）的结果。我们研究了拟南芥中SEUSS和LEUNIG基因在花瓣发育中的作用，以便更好地理解植物中细胞生长与器官形态是如何协调的分子机制。SEUSS和LEUNIG编码一种假定的转录调控复合物的组分，该复合物通过抑制花器官特征基因AGAMOUS来控制器官特征的确定。SEUSS和LEUNIG还通过不依赖AGAMOUS的机制调节花瓣形状；然而，SEUSS和LEUNIG在花瓣发育过程中的分子和细胞作用尚不清楚。在此我们表明，SEUSS和LEUNIG控制花瓣内的叶片细胞数量和维管系统发育。此外，SEUSS和LEUNIG沿近轴/远轴轴调节花瓣极性。我们提出了一个模型，其中SEUSS和LEUNIG是增强关键极性基因PHABULOSA和丝状花/YABBY1所必需的，从而影响发育中的花瓣叶片内的细胞生长。
