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bioRxiv · 10.1101/119925

The Rice XA21 Ectodomain Fused to the Arabidopsis EFR Cytoplasmic Domain Confers Resistance to Xanthomonas oryzae pv. oryzae

Thomas, N. C.·Oksenberg, N.·Liu, F.·Caddell, D.·Nalyvayko, A.·Nguyen, Y.·Schwessinger, B.·Ronald, P.
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Abstract

O_LIRice (Oryza sativa) plants expressing the XA21 cell surface receptor kinase are resistant to Xanthomonas oryzae pv.oryzae (Xoo) infection. We previously demonstrated that expressing a chimeric protein containing the EFR (ELONGATION FACTOR Tu RECEPTOR) ectodomain and the XA21 endodomain (EFR:XA21) in rice does not confer robust resistance to Xoo.\nC_LIO_LITo test if the XA21 ectodomain is required for Xoo resistance, we produced transgenic rice lines expressing a chimeric protein consisting of the XA21 ectodomain and EFR endodomain (XA21:EFR) and inoculated these lines with Xoo. We also tested if the XA21:EFR rice plants respond to a synthetic sulfated 21 amino acid derivative (RaxX21-sY) derived from the activator of XA21-mediated immunity, RaxX.\nC_LIO_LIWe found that five independently transformed XA21:EFR rice lines displayed resistance to Xoo as measured by lesion length analysis, and showed that five lines express markers of the XA21 defense response (generation of reactive oxygen species and defense response gene expression) after treatment with RaxX21-sY.\nC_LIO_LIOur results indicate that expression of the XA21:EFR chimeric receptor in rice confers resistance to Xoo. These results suggest that the endodomain of the EFR and XA21 immune receptors are interchangeable and the XA21 ectodomain is the key determinant conferring robust resistance to Xoo.\nC_LI

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Thomas, N. C., Oksenberg, N., Liu, F., Caddell, D., Nalyvayko, A., Nguyen, Y., Schwessinger, B., Ronald, P.. 2017-03-23. The Rice XA21 Ectodomain Fused to the Arabidopsis EFR Cytoplasmic Domain Confers Resistance to Xanthomonas oryzae pv. oryzae. https://doi.org/10.1101/119925

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