Model of MYB26 regulation of anther secondary thickening pathway. MYB26 regulation of secondary thickening through downstream the redundant transcription factors NST1/NST2. Arrows represent direct regulation, while bar represents repression, and dotted lines represent predicted regulation/repression. X = unknown factor that enables NST1/2 to initiate secondary thickening. This could be via NST1/2 protein activation/stabilization or removal of an inhibitor involved in NST1/2 degradation/turnover. AHP4, ARABIDOPSIS HISTIDINE-CONTAINING PHOSPHOTRANSFER FACTOR 4; HDG3, HOMEODOMAIN GLABRA 2-LIKE PROTEIN 3; TCP24 and WRKY2, transcription factor; JA, Jasmonic Acid; DAD1, DEFECTIVE IN ANTHER DEHISCIENCE1; OPR3, 12-OXOPHYTODIENOATE REDUCTASE 3; WAT1, WALLS ARE THIN1.