Ectopic expression of TaYAB1, a member of YABBY gene family in wheat, causes the partial abaxialization of the adaxial epidermises of leaves and arrests the development of shoot apical meristem in Arabidopsis

Adaxial–abaxial polarity is an important feature of lateral organs. To study the molecular mechanism of polarity establishment, a YABBY gene TaYAB1 was isolated from the young leaves of wheat. TaYAB1 has a zinc finger-like domain in the N terminus and a YABBY domain in the C terminus. Sequence comparison showed that TaYAB1 is a putative member of the YABBY gene family in wheat. Further expression analysis indicated that TaYAB1 was expressed in the lateral organs of wheat. Ectopic expression of TaYAB1 in Arabidopsis caused the partial abaxialization of the adaxial epidermises of leaves and arrested shoot apical meristem development with the reduction of the transcript levels of SHOOT MERISTEMLESS (STM). Our results indicate that TaYAB1 affects the establishment of adaxial–abaxial polarity and the development of shoot apical meristem when ectopically expressed in Arabidopsis.