Crop Biotech Update

INRA Researchers Discover Genes for Compound Leaf Formation

January 16, 2009

Plant leaves can be simple, a single leaf blade, or compound when divided to distinct leaflets. In addition, margins of both simple and compound leaves can have serrations or lobes. Scientists from the French National Institute for Agricultural Research and Oxford University have pinpointed the family of genes responsible for leaflet formation in dicots.

Researchers focused on the NAM/CUC3 gene family, which is involved in the development of boundary domains separating the leaves when they begin to grow from stems. The scientists studied the expression of these genes in columbine, tomato, cardamine and pea, distantly related plants that have leaflets. They found that these genes were expressed in boundary domains surrounding the young leaflets, and that this expression preceded leaflet emergence. Using mutants with defective NAM/CUC3 expression, the researchers were able to provide proof of the gene family’s importance. Without them, leaf development was abnormal. Serrated edges disappeared, leaflets were fused, and leaflet numbers decreased.

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