AUTHOR=Wang Lulu , Liu Yanhui , Aslam Mohammad , Jakada Bello Hassan , Qin Yuan , Cai Hanyang 

TITLE=The Glycine-Rich Domain Protein GRDP2 Regulates Ovule Development via the Auxin Pathway in Arabidopsis

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.698487

DOI=10.3389/fpls.2021.698487

ISSN=1664-462X

ABSTRACT=<p>The glycine-rich domain proteins (<italic>GRDP</italic>) have been functionally implicated in the cell wall structure, biotic, and abiotic stress responses. However, little is known about <italic>GRDP</italic> genes in female gametophyte development of <italic>Arabidopsis</italic>. This study shows that <italic>GRDP2</italic>, a <italic>GRDP</italic>, plays a crucial role in female gametophyte development. In <italic>GRDP2</italic> overexpression lines, <italic>grdp2-3</italic>, the embryo sacs were arrested at FG1 and no nucleus stages. Furthermore, callose staining shows that cell plate formation during megasporogenesis is disturbed in <italic>grdp2-3</italic>. In contrast, the pollen development is not affected in <italic>grdp2-3</italic>. The expression patterns of auxin-specific marker lines in female gametophytes showed that the auxin distribution and transport were significantly changed during megagametogenesis in <italic>grdp2-3</italic>. In addition, compared with the membrane-localized pattern of <italic>PIN1</italic>, <italic>PIN2</italic>, and <italic>PIN7</italic> in WT, the signals were detected in the cytoplasm in <italic>grdp2-3</italic>. Together, our data suggest that <italic>GRDP2</italic> plays an essential role in auxin-mediated female gametophyte development.</p>