Our results strongly suggested that formation of embryonic callus from the shoot apical meristem and hairy phenotype of the callus. Hormones play key roles in embryo development and somatic embryogenesis. Braybrook showed that LEC2 activated gene expression of IAA30, one of auxin signaling proteins, which may affect plant response to auxin or confer competency for somatic embryogenesis. Stone proved that LEC2 also induced genes involved in auxin biosynthesis such as YUC2, YUC4, IAA1, IAA17 and ACS4. Our study showed that both PIN1 and PIN2 were induced in LEC2 transgenic tobacco. Auxin-responsive genes, including ARF3, ARF5 and ARF8, play diverse roles in reproductive organ and embryo developmental processes. We found that ARF5, ARF8 and ARF10 were activated by LEC2. IAA13, a negative AbMole Mepiroxol regulator in auxin signaling, was downregulated. ARF19 which can be induced by IAA or ethylene treatment was down-regulated. Roustan showed that inhibition of ethylene production can increase somatic embryogenesis. Genes involved in ethylene biosynthesis and response were down-regulated in super-embryogenic line 2HA compared with the non-embryogenic progenitor. Somatic embryogenesis was enhanced by AgNO3, an ethylene inhibitor, in several plant species. Zheng showed that expression of some genes involved in ethylene signaling pathway and that ethylene production was increased in the process of GmAGL15 promoting somatic embryogenesis in soybean. Our results showed that most genes involved in ethylene signaling pathway were down-regulated by LEC2. CKX expression could lead to more root branches and larger root meristem. Up-regulation of ARF10 and CKX was consistent with the densely grown hairy structure on embryonic callus and longer roots of LEC2 overexpressor. MYC2, a positive regulator in JA signaling, was down-regulated. Chen showed that MYC2 directly represses expression of PLT1 and PLT2 which are important transcription factors in auxin signaling pathways. Previous studies indicated that reduced levels of GA induced somatic embryo formation and that LEC2 repressed the expression of GA biosynthesis gene GA3ox2. In our study, over expressing LEC2 reduced the expression of GA3ox2, however, the gene expression of GA inactive enzyme GA2ox and the GA signaling negative factor DELLA was also down-regulated in transgenic tobacco. Several members of the ABI family are key transcriptional factors that regulate late embryogenesis and seed maturation. ABI gene was up-regulated in LEC2 transgenic tobacco. LEC1 and LEC2 could repress anthocyanin accumulation, trichomes formation and induce chlorophyll degradation and desiccation tolerance through activation of FUS3 and ABI3. We found that genes involved in biosynthesis of anthocyanin, chlorophyll and genes in photosynthesis were down-regulated in transgenic seedlings. However, we did not detect any significant changes in FUS3 in the transgenic tobacco plants.