Fig. 6.
From: What are karrikins and how were they ‘discovered’ by plants?
Parallels between karrikin signalling and strigolactone signalling. Karrikins depend on KAI2 protein (shown in red) for signalling, while strigolactones signal via interaction with its paralog DWARF14 (green). Both are thought to signal by triggering the degradation of closely related proteins, SMAX1 in Arabidopsis and DWARF53 in rice, which requires orthologous proteins known as MAX2 (or KAI1) in Arabidopsis and DWARF3 in rice. Since DWARF53 and SMAX1 influence different processes, the effects of karrikins and strigolactones on plant development are different. DWARF53 promotes shoot branching, so its degradation in response to strigolactone and DWARF14 inhibit shoot branching. The converse is true for stem thickening. Similar processes operate to regulate seed germination and seedling development by SMAX1