Fig. 5: Model of the mechanisms underlying the growth-promoting effect of zaxinone in rice.
Application of zaxinone might enhance photosynthesis activity (Calvin cycle) that produces sucrose that is translocated from the shoot (source) to developing root tissues (sink). Sucrose then can either be hydrolyzed (glycolysis) into hexose that enters glycolysis and citric acid cycle (to produce ATP and C-building blocks), or stores as starch formed by gluconeogenesis. The glucose can also be used for cytokinin glycosylation that regulates the bioactivity of CKs in rice root tissues. A combination of these effects results in root phenotypical changes and cellular events, such as a larger meristem size. In addition, zaxinone suppresses SL biosynthesis and release, while it cannot rescue the SL biosynthesis and perception mutants22 and does not affect the central metabolism in the SL biosynthetic d17 mutant. Created with “Biorender”.
