The phyllody phenotype in the ‘‘green rose’’ resembles the phenotypes of the Arabidopsis class B and C double mutants and the sepallata 1/2/3 triple mutant [26]. Similarly, the transformation of pistils to leaf-like organs in abnormal ‘Motrea’ flowers implies mis-expression of class C genes [12]. Yet, Matsumoto and Kiahara (2005) reported that the expression of B, C and SEPALLATA genes in ‘‘green rose’’ floral organs was the same as that in normal rose flowers, whereas
Chmelnitsky et al. [12] found that the C class gene RAG was not expressed in the phylloids of ‘Motrea’ and ‘‘green rose’’ floral organs during the early stages of development. RAG was, however, expressed in these organs at later stages, although not in the leafy parts of the transformed organs. Thus, it is still unclear whether conversions into phylloid structures are associated with abnormal expression of the genes involved in the control of flower organ identity. The transformation of the first sepal of BPP flowers into a phylloid organ and the change in identity of the following floral
organs could reflect abnormal expression of class A and B genes [5]. Further identification of class A genes from roses and expression pattern analysis of class A and B in normal and BPP buds is needed to test this possibility.