The invention relates to a method for enhancing the differentiation of cells in culture, particularly for the tissue differentiation, embryogenesis and/or organogenesis, characterized in that at least one lipid transfer protein or "LTP" or an LTP analog is introduced in the culture medium in a concentration efficient to obtain the cell differentiation. The invention also relates to a plant obtained by such a method, proteinic substances and proteins having a lipid transfer activity, and a composition comprising at least such substance. It also relates to a DNA sequence coding for an LTP and a probe whose sequence is deduced from the sequence of said protein.
