Fig. 6.

Gene and metabolite regulation involved in starch and sucrose metabolic processes, and sucrose signaling. (A) Starch biosynthesis process. (B) Sucrose metabolism. (C) Sucrose signaling involved in the trehalose metabolism pathway. Heat maps next to the arrows represent changes in expression of genes encoding corresponding enzymes for reactions. The expression levels are standardized per gene into Z-scores and colored in red and green for high and low expression, respectively. (D) Verification of expression levels of genes encoding SUS1, VIF1, and TPS1 determined by qRT–PCR. (E) Sucrose accumulation in bulbils, demonstrating that sucrose is sharply increased at the early stage of bulbil formation (T1). Data show the mean ±SD (n=5). ADG, glucose-1-phosphate adenylyltransferase; CIN, cell wall invertase; FRK, fructokinase; HXK, hexokinase; SBE, glucan-branching enzyme; SUS, sucrose synthase; TPP, trehalose-phosphate phosphatase; TPS, trehalose-phosphate synthase; VIF1, vacuolar invertase1.