Anti actin

The rice leaves were ground into a fine powder in liquid nitrogen to extract the total proteins using the extraction buffer (25 mM Tris-HCl [pH 7.4], 150 mM NaCl, 1 mM EDTA, 1% Nonidet P-40, 5% glycerol) with 1 mM phenylmethylsulfonyl fluoride (PMSF), and Roche protease inhibitor cocktail (Roche, Basel, Switzerland) (Wang et al., 2020a) . The total proteins were then resolved in 10% SDS-PAGE gels and immunoblotted with anti-phospho-p44/p42 MAPK (Cell Signaling, Boston, MA, USA) and anti-Actin (CWbio, Beijing, China) antibodies. The intensities of the Western blot bands were measured using the ImageJ software.
For co-IP assays, the coding sequence of OsMYC2 was cloned into the pHY35S-FLAG vector to obtain the OsMYC2-FLAG construct. The resultant construct was introduced into A. tumefaciens and then infiltrated into tobacco leaves. Total proteins were extracted from the tobacco leaves with protein extraction buffer ], 150 mM NaCl, 1 mM EDTA, 1% Nonidet P-40, 5% glycerol, 1 mM PMSF, 20 mM MG132, and 13 Roche protease inhibitor cocktail) and then mixed with the OsMYB22-GST protein. co-IP was performed with FLAG-trap magnetic beads (Sigma, M8823-5ML) as previously described (Wang et al., 2020a) . Western blotting was carried out with anti-FLAG (Sigma, A8592-1MG) and anti-GST (Sigma, G7781-0.2ML) antibodies. Two replicates were carried out for this experiment.

Arabidopsis tissues were ground in liquid nitrogen and total proteins were extracted with extraction buffer (50-mM Tris-HCl, pH 7.5, 150-mM NaCl, 10% [v/v] glycerol, 1% [v/v] Nonidet P-40, and 1 × complete protease inhibitor cocktail [Roche]). Cytoplasmic and nuclear fractions were extracted as described previously (Ryu et al., 2007) . Three percent of the cytoplasmic fractions and 10% of the nuclear fractions were used for immunoblot assays. Immunoblotting was performed following standard procedures. The antibodies used were as follows: anti-C3H14 (custom made), anti-Myc (Roche, catalog no. 10653800), anti-phosphoserine (Sigma-Aldrich, catalog no. P3430), anti-MPK4 (Abcam, catalog no. ab49780), anti-ACTIN (Cwbio, catalog no. CW0264M), anti-H3 (Beyotime, catalog no. AF0009), peroxidase-conjugated goat anti-mouse IgG (Sigma-Aldrich, catalog no. A2304), and HRP-conjugated goat anti-mouse IgG (Cwbio, catalog no. C20102S). The anti-C3H14 polyclonal antibody was produced in mice against its full-length protein and purified using an IgG-affinity chromatography column (GE Healthcare) (Institute of Genetics and Developmental Biology, Chinese Academy of Sciences).