The order Zingiberales is comprised of eight families of economically important plants, ranging from banana and ginger to bird-of-paradise and heliconia. Species in this order display remarkable diversity in floral from, most notably in the androecial whorls where stamens are absent or have been replaced by petal-like organs. The most basal families display five or six fertile stamens, but more advanced lineages have up to five petaloid staminodes in the place of fertile stamens. Previous studies of floral MADS-box transcription factors in model systems have shown that changes in their relative spatial and temporal expression patterns can produce similar homeotic changes of floral organs, such as a transformation from stamens to petals or petaloid staminodes. We have initiated an investigation of the relative spatial and temporal expression of both mRNA and protein expression of the B (APETALA3 and PISTILLATA) and C (AGAMOUS) class MADS-box transcription factors to determine the genetic basis for the change from stamens to staminodes in the order. In this poster, we present the APETALA3/PISTILLATA orthologues from Musella lasiocarpa as the initial stage of this study, and discuss its implications and directions for future research.

Key words: AGAMOUS, APETALA3/PISTILLATA, development, evolution, staminode, Zingiberales