*4.5. Western Blot Analysis*

Protein was extracted from 50 mg leaf blades with 300 μL SDS–urea buffer (8 M urea, 5% SDS, 0.1 mM EDTA, 2% 2-mercaptoethanol, 1 mM phenylmethanesulfonylfluoride (PMSF), 2 × complete

inhibitor mix, EDTA-free (Roche, Basel, Switzerland), 40 mM Tris-HCl: pH 6.8) according to a previously described method [52]. An equal volume of each SDS–urea sample was used for the western analysis. HPB-tagged protein was detected using anti-HA antibody (Anti-HA.11, Mouse-Mono 16B12; BAB).

**Supplementary Materials:** The following are available online at http://www.mdpi.com/1422-0067/20/22/5523/s1.

**Author Contributions:** Conceptualization, Y.K., Y.N., T.K., and M.M.; resources H.N.; formal analysis, Y.K.; writing—original draft preparation, Y.K.; writing—review and editing, H.N., Y.N., and M.M.; supervision, Y.N., T.K., and M.M.; project administration, M.M.

**Funding:** This research received no external funding.

**Acknowledgments:** We thank Fumiaki Katagiri (University of Minnesota) for providing pMDC32-HPB. We thank Shoji Sugano and Satoru Maeda (NIAS, Japan) for assistance in western analyses and fungal blast infection, respectively. We thank Eiichi Minami (NIAS, Japan) for providing a luminometer, and Naoto Shibuya and Yoshitake Desaki (Meiji University) for providing the bundled razor blades used in the H2O2 concentration experiments. We also thank Lois Ishizaki and Yuka Yamazaki (NIAS, Japan) for their help during the rice transformation experiments and for their overall technical assistance. We thank Lesley Benyon, from Edanz Group (www.edanzediting.com/ac) for editing a draft of this manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
