Fig. 5. Identification and characterization of TaBX10 as a functional DIMBOA-Glc OMT.

(A) Recombinant TaBX10 methylates DIMBOA-Glc and DIM₂BOA-Glc. The enzyme was heterologously expressed in E. coli, purified, and incubated with a mixture of DIMBOA-Glc and DIM₂BOA-Glc. Enzyme products were analyzed using liquid chromatography–tandem mass spectrometry (LC-MS/MS). CPS, counts per second (electron multiplier). (B) Phylogenetic tree of Poaceae OMT genes similar to Bx7. Maize Bx7,10,11,14 and wheat TaBx10 are shown in red and green, respectively. The tree represents a subclade of a larger Poaceae OMT tree that is given in fig. S13. The tree was inferred by using the maximum likelihood method based on the Tamura 3-parameter model. Bootstrap values are shown next to each node. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. Zm, Zea mays; Sb, Sorghum bicolor; Sv, Setaria viridis; Si, S. italica; Pv, Panicum virgatum; Ph, P. hallii; Ot, Oropetium thomaeum; Ta, T. aestivum; Hv, Hordeum vulgare; Bd, Brachypodium distachyon; Bs, B. stacei; Os, Oryza sativa. The PACMAD lineage–specific Bx10 clade is marked in red, and its sister clade is marked in blue.