YABBY2-homologue expression in lateral organs of Amborella trichopoda (Amborellaceae)

YABBY genes ( CRABS CLAW, LAMENTOUS FLOWER, YABBY2, and YABBY3) are expressed on the abaxial side of lateral organs, such as leaves, and are involved in the establishment of abaxial tissue identity in the eudicot Arabidopsis thaliana. Here we report the expression patterns of a YABBY2 homologue in the lateral organs of Amborella trichopoda, an early-diverging angiosperm. We found that the homologue is expressed in the adaxial tissues of the carpel and leaf, in contrast to abaxial expression in A. thaliana, which indicates that different patterns of YABBY2 expression evolved within the angiosperms.