Fig. 1.

Phosphorylation motifs enriched from differentially phosphorylated peptides after salt treatment. A, and B, are phosphorylation motifs extracted from the phosphopeptides in the Up group and Down group, respectively, when the soybean roots were inoculated with rhizobia. C, and D, show phosphorylation motifs extracted from the phosphopeptides in the Up and Down groups when the rhizobia-inoculated root was treated with NaCl. E, GmMYB183 could be a substrate of GmCK2α. Phosphorylation assay was carried out as described in the experimental procedures. WT and S61D: recombinant proteins of the N-terminal 168 aa of GmMYB183-S61D and GmMYB183-WT fused to a Trx- and a 6 x His-tags at its N terminus, and a 6 x His-tag at its C terminus. Data indicated that the Ser61 is the unique site in GmMYB183.