Overexpression of Rice Auxilin-Like Protein, XB21, Induces Necrotic Lesions, up-Regulates Endocytosis-Related Genes, and Confers Enhanced Resistance to <i>Xanthomonas oryzae</i> pv. <i>oryzae</i>

다국어 초록 (Multilingual Abstract)

<P><B>Background</B></P><P>The rice immune receptor XA21 confers resistance to the bacterial pathogen, <I>Xanthomonas oryzae</I> pv. <I>oryzae</I> (<I>Xoo</I>). To elucidate the mechanism of XA21-mediated immunity, we previously performed a yeast two-hybrid screening for XA21 interactors and identified XA21 binding protein 21 (XB21).</P><P><B>Results</B></P><P>Here, we report that XB21 is an auxilin-like protein predicted to function in clathrin-mediated endocytosis. We demonstrate an XA21/XB21 in vivo interaction using co-immunoprecipitation in rice. Overexpression of <I>XB21</I> in rice variety Kitaake and a Kitaake transgenic line expressing XA21 confers a necrotic lesion phenotype and enhances resistance to <I>Xoo</I>. RNA sequencing reveals that <I>XB21</I> overexpression results in the differential expression of 8735 genes (4939 genes up- and 3846 genes down-regulated) (≥2-folds, FDR ≤0.01). The up-regulated genes include those predicted to be involved in ‘cell death’ and ‘vesicle-mediated transport’.</P><P><B>Conclusion</B></P><P>These results indicate that XB21 plays a role in the plant immune response and in regulation of cell death. The up-regulation of genes controlling ‘vesicle-mediated transport’ in XB21 overexpression lines is consistent with a functional role for XB21 as an auxilin.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s12284-017-0166-1) contains supplementary material, which is available to authorized users.</P>