Finally, the mature and dormant seeds with a quiescent metabolic embryo are formed. Somatic embryogenesis is that somatic cells, under inductive conditions, undergo a series of biological process to generate somatic embryos. The somatic embryos undergo processes closely resemble that of zygotic embryogenesis. Somatic embryogenesis provides a model system for studying molecular and biochemical mechanism of zygotic embryogenesis. Many crops exhibit low efficiency of regeneration, which may negatively affect the progress of yield, quality or stress tolerance improvement by genetic modification. Increasing the regeneration rate of crops through either somatic embryogenesis or organogenesis and establishment of high efficient plant regenerating system is a key step for gene engineering improvement of crops 
such as soybean, cotton and peanut. Leafy Cotyledon genes including LEC1 and LEC2 are key regulators of plant embryo development. They play key roles during both embryo morphogenesis and maturation phases. Both lec1 and lec2 mutant embryos are known to show trichomes on the cotyledons, lack of embryospecific proteins and loss of desiccation tolerance. LEC1 encodes HAP3 subunit of CCAAT-binding transcription factor. Ectopic expression of LEC1 gene was sufficient to confer transgenic seedlings embryonic characteristics and to induce embryo-like structures from vegetative organs in Arabidopsis. These results indicated the ability of LEC1 to induce vegetative- toembryonic transition. LEC1 over expression caused accumulation of seed-specific storage protein and oil body protein in vegetative tissues. Fatty acid biosynthetic genes were globally upregulated in LEC1 overexpressor. The role of LEC1 maintaining embryonic characteristics in vegetative organs requires auxin and sugars. The phenotype of Arabidopsis tnp mutant, a gain-of-function mutant of LEC1, could be strengthened with exogenous auxin and sugars. LEC1-LIKE that shows sequence similarity with LEC1, is required for normal embryogenesis. Although L1L and LEC1 play different roles during embryo development, ectopic expression of L1L could rescue the defect of lec1 mutant. Another member of LEC genes, LEC2, encodes B3 domain transcription factors which are unique to plants. The lec2 mutation caused pleiotropic defects in embryo development. Ectopic expression of LEC2 caused accumulation of lipid and seed storage protein in transgenic seedlings. A number of genes regulated by LEC2 were identified, AbMole Neosperidin-dihydrochalcone providing information about the role of LEC2 in somatic embryogenesis. Auxin biosynthesis genes YUC2 and YUC4 can be activated by LEC2. The capacity of somatic embryogenesis in lec1lec2 double mutants was very low even in the presence of auxin. This suggested that formation of somatic embryo by auxin needs the function of LEC genes. In addition, many genes such as SERK, AGL15, BBM, WUS and PKL are involved in somatic embryogenesis.