ATLTP1 LUCIFERASE EXPRESSION DURING CARROT SOMATIC EMBRYOGENESIS

The carrot (Daucus carota L.) EP2 gene encodes a Lipid Transfer Protei n (LTP) which is expressed during protoderm formation in developing em bryos. To develop a vital reporter system for gene expression during s omatic embryo development a 1.1 kB fragment of the Arabidopsis thalian a LTP1 promoter was fused to the firefly luciferase (LUG) coding seque nce. The AtLTP1 luciferase expression pattern in transformed carrot su spension cultures was identical to the expression pattern of the endog enous carrot EP2 gene. Cell tracking experiments revealed that all som atic embryos were derived from AtLTP1 luciferase expressing cell clust ers. However, not all cell clusters that expressed the AtLTP1 lucifera se reporter gene developed into a somatic embryo, suggesting that init iation of an embryogenic pathway in tissue culture does not always lea d to development of a somatic embryo.