Schematic pathway of the biosynthesis of MAs and expression changes in the related genes. A) DMA is the sole MAs synthesized in rice. DMA is synthesized from S-adenosyl-l-methionine (SAM) by NAS, NAAT, and DMAS. B) Changes in the expression of MAs-biosynthetic genes. C) Changes in the expression of TOM1 and OsYSL15.