On 2016 Apr 18, PAMELA RONALD commented:

Following the publication of this Article, we discovered that Xanthomonas oryzae pv. oryzae (Xoo) lacking the peptide Ax21 is still able to trigger XA21-mediated immunity^1. Furthermore, we were unable to consistently reproduce experiments demonstrating that synthetic AxYS22 triggers XA21-mediated immunity^2,3,4.

In light of these results, we repeated the experiments reported in this Article. We found that neither AxYS22 nor Xoo enhance accumulation of the XA21-GFP protein beyond that observed following mock treatment. Shredding of leaf tissue (mock), with or without treatment, induces higher levels of XA21-GFP protein and correspondingly higher levels of the cleavage product as compared with the unshredded control. The presence of higher levels of cleavage product after wounding or Xoo treatment facilitates detection. Based on these results, we can no longer ascribe a role for Xoo or AxYs22 in XA21-GFP cleavage.

These findings do not alter the main conclusion of this Article that XA21-GFP is cleaved and translocates to the nucleus of protoplasts when transiently overexpressed and that the putative nuclear localization sequence (NLS) is required for localization. We are currently investigating the in vivo biological relevance of the putative NLS in the rice immune response. This notice of correction was first submitted to the editors April 7, 2014.

1. Bahar, O. P., Pruitt, R., Luu, D. D., Schwessinger, B., Daudi, A., Liu, F., Ruan, R., Fontaine-Bodin, L., Koebnik, R. & Ronald, P. C. The Xanthomonas Ax21 protein is processed by the general secretory system and is secreted in association with outer membrane vesicles. PeerJ 2, e242 (2014).
2. Lee, S. W., Han, S. W., Sririyanum, M., Park, C. J., Seo, Y. S. & Ronald, P. C. A type I-secreted, sulfated peptide triggers XA21-mediated innate immunity. Science 326, 850–853 (2009).
3. Lee S. W., Han S. W., Sririyanum M., Park C. J., Seo Y. S. & Ronald P. C. Retraction. Science 342, 191 (2013).
4. Ronald P. C. 2013. Lab Life: The Anatomy of a Retraction, Scientific American. October 10, 2013. http://blogs.scientificamerican.com/food-matters/2013/10/10/lab-life-the-anatomy-of-a-retraction/

On 2016 Apr 18, PAMELA RONALD commented:

Following the publication of this Article, we discovered that Xanthomonas oryzae pv. oryzae (Xoo) lacking the peptide Ax21 is still able to trigger XA21-mediated immunity^1. Furthermore, we were unable to consistently reproduce experiments demonstrating that synthetic AxYS22 triggers XA21-mediated immunity^2,3,4.

In light of these results, we repeated the experiments reported in this Article. We found that neither AxYS22 nor Xoo enhance accumulation of the XA21-GFP protein beyond that observed following mock treatment. Shredding of leaf tissue (mock), with or without treatment, induces higher levels of XA21-GFP protein and correspondingly higher levels of the cleavage product as compared with the unshredded control. The presence of higher levels of cleavage product after wounding or Xoo treatment facilitates detection. Based on these results, we can no longer ascribe a role for Xoo or AxYs22 in XA21-GFP cleavage.

These findings do not alter the main conclusion of this Article that XA21-GFP is cleaved and translocates to the nucleus of protoplasts when transiently overexpressed and that the putative nuclear localization sequence (NLS) is required for localization. We are currently investigating the in vivo biological relevance of the putative NLS in the rice immune response. This notice of correction was first submitted to the editors April 7, 2014.

1. Bahar, O. P., Pruitt, R., Luu, D. D., Schwessinger, B., Daudi, A., Liu, F., Ruan, R., Fontaine-Bodin, L., Koebnik, R. & Ronald, P. C. The Xanthomonas Ax21 protein is processed by the general secretory system and is secreted in association with outer membrane vesicles. PeerJ 2, e242 (2014).
2. Lee, S. W., Han, S. W., Sririyanum, M., Park, C. J., Seo, Y. S. & Ronald, P. C. A type I-secreted, sulfated peptide triggers XA21-mediated innate immunity. Science 326, 850–853 (2009).
3. Lee S. W., Han S. W., Sririyanum M., Park C. J., Seo Y. S. & Ronald P. C. Retraction. Science 342, 191 (2013).
4. Ronald P. C. 2013. Lab Life: The Anatomy of a Retraction, Scientific American. October 10, 2013. http://blogs.scientificamerican.com/food-matters/2013/10/10/lab-life-the-anatomy-of-a-retraction/