“…The number of embryos obtained was reduced if the concentration ratio of auxin: sucrose was high, or vice versa. In the study of somatic embryogenesis in Phaseolus vulgaris induced by 2,4-D, it was shown that there was an inverse relationship between 2,4-D concentration in the medium and endogenous IAA level in the globular structures (Dobrev et al, 2001). Using an immunocytochemical approach to visualize IAA it was shown in sunflower somatic embryos that an endogenous auxin pulse induced by the application of exogenous auxin is needed as one of the first signals inducing embryogenesis (Thomas et al, 2002).…”