AUTHOR=Zhang Tao , Li Ruonan , Xing Jialing , Yan Lang , Wang Rongchen , Zhao Yunde 

TITLE=The YUCCA-Auxin-WOX11 Module Controls Crown Root Development in Rice

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 9 - 2018

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00523

DOI=10.3389/fpls.2018.00523

ISSN=1664-462X

ABSTRACT=<p>A well-developed root system in rice and other crops can ensure plants to efficiently absorb nutrients and water. Auxin is a key regulator for various aspect of root development, but the detailed molecular mechanisms by which auxin controls crown root development in rice are not understood. We show that overexpression of a <italic>YUC</italic> gene, which encodes the rate-limiting enzyme in auxin biosynthesis, causes massive proliferation of crown roots. On the other hand, we find that disruption of <italic>TAA1</italic>, which functions upstream of <italic>YUC</italic> genes, greatly reduces crown root development. We find that <italic>YUC</italic> overexpression-induced crown root proliferation requires the presence of the transcription factor WOX11. Moreover, the crown rootless phenotype of <italic>taa1</italic> mutants was partially rescued by overexpression of <italic>WOX11</italic>. Furthermore, we show that <italic>WOX11</italic> expression is induced in <italic>OsYUC1</italic> overexpression lines, but is repressed in the <italic>taa1</italic> mutants. Our results indicate that auxin synthesized by the TAA/YUC pathway is necessary and sufficient for crown root development in rice. Auxin activates <italic>WOX11</italic> transcription, which subsequently drives crown root initiation and development, establishing the YUC-Auxin-WOX11 module for crown root development in rice.</p>