植物的叶子即可以是一个简单的叶片，也可以由多个单独的小叶组成。此外，无论单叶还是复叶都可能具有齿状或圆突状的边缘。法国国家农业研究所和牛津大学的科学家找到了负责双子叶植物叶片形成的基因家族。
研究人员重点研究了NAM/CUC3基因家族，当叶子从茎上生长时，这类基因使叶子的边界区域出现分离。科学家们研究了这些基因在耧斗菜、西红柿、碎米芥和豌豆等具有小叶的一类远亲植物中的表达情况。他们发现，这些基因在嫩叶周围的边界区域中表达，并且这种表达要先于叶子出现。利用具有NAM/CUC3缺陷表达的突变体，研究人员证明了这类基因家族的重要性。没有这些基因，叶子生长就会出现反常，锯齿状边缘消失，小叶长在一起，并且叶子数目减少。（生物谷Bioon.com）
生物谷推荐原始出处：
Science 19 December 2008:DOI: 10.1126/science.1166168
A Conserved Molecular Framework for Compound Leaf Development
Thomas Blein,1 Amada Pulido,1 Aurélie Vialette-Guiraud,1* Krisztina Nikovics,1 Halima Morin,1,2 Angela Hay,3 Ida Elisabeth Johansen,4 Miltos Tsiantis,3 Patrick Laufs1
Diversity in leaf shape is produced by alterations of the margin: for example, deep dissection leads to leaflet formation and less-pronounced incision results in serrations or lobes. By combining gene silencing and mutant analyses in four distantly related eudicot species, we show that reducing the function of NAM/CUC boundary genes (NO APICAL MERISTEM and CUP-SHAPED COTYLEDON) leads to a suppression of all marginal outgrowths and to fewer and fused leaflets. We propose that NAM/CUC genes promote formation of a boundary domain that delimits leaflets. This domain has a dual role promoting leaflet separation locally and leaflet formation at distance. In this manner, boundaries of compound leaves resemble boundaries functioning during animal development.
1 Laboratoire de Biologie Cellulaire, Institut Jean Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), 78026 Versailles Cedex, France.
2 Plateforme de Cytologie et d'Imagerie Végétale, Institut Jean Pierre Bourgin, INRA, 78026 Versailles Cedex, France.
3 Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
4 Department of Genetics and Biotechnology, University of Aarhus, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
