AUTHOR=Sawettalake Nunchanoke , Bunnag Sumontip , Wang Yanwen , Shen Lisha , Yu Hao 

TITLE=DOAP1 Promotes Flowering in the Orchid Dendrobium Chao Praya Smile

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00400

DOI=10.3389/fpls.2017.00400

ISSN=1664-462X

ABSTRACT=<p><italic>APETALA1</italic> (<italic>AP1</italic>) encodes a key MADS-box transcription factor that specifies the floral meristem identity on the flank of the inflorescence meristem, and determines the identity of perianth floral organs in the model plant <italic>Arabidopsis thaliana</italic>. Orchids are members of the Orchidaceae, one of the largest families of angiosperms. Although the expression patterns of a few <italic>AP1</italic>-like genes in orchids have been reported, their actual functions in orchid reproductive development are so far largely unknown. In this study, we isolated and characterized an <italic>AP1</italic> ortholog, <italic>DOAP1</italic>, from <italic>Dendrobium</italic> Chao Praya Smile. <italic>DOAP1</italic> was highly expressed in reproductive tissues, including inflorescence apices and flowers at various developmental stages. Overexpression of <italic>DOAP1</italic> resulted in early flowering in <italic>Arabidopsis</italic>, and was able to rescue the floral organ defects of <italic>Arabidopsis ap1</italic> mutants. Moreover, we successfully created transgenic <italic>Dendrobium</italic> Chao Praya Smile orchids overexpressing <italic>DOAP1</italic>, which displayed earlier flowering and earlier termination of inflorescence meristems into floral meristems than wild-type orchids. Our results demonstrate that <italic>DOAP1</italic> plays an evolutionarily conserved role in promoting flowering and floral meristem specification in the Orchidaceae family.</p>