A corolla- and carpel-abundant, non-specific lipid transfer protein gene is expressed in the epidermis and parenchyma of Gerbera hybrida var. Regina (Compositae).

We are examining the floral organ differentiation in Compositae by isolating and characterizing corolla abundant genes. Differential screening of a cDNA library made from the ray floret corolla of Gerbera hybrida var. Regina revealed an abundant cDNA clone which is expressed in the corolla but not in leaves. This cDNA (gltp1) codes for a polypeptide similar to non-specific lipid transfer proteins of the plants. The gltp1 gene is expressed only in the corolla and carpels and is developmentally regulated during corolla development. The gltp1 mRNA accumulates both in epidermal cell layers and in the mesophyll of the corolla. In the stylar part of the carpel, the gltp1 mRNA can be detected in the epidermal and in parenchymal cells but not in the transmitting tissue. Analogous patterns of gltp1 expression in the corolla and carpel may indicate that similar genetic programmes operates during the development of these two tissues.