Plant sugar sensors and uses thereof

A method for modifying sugar sensitivity in a transgenic plant cell by increasing the level of a hexokinase protein in said transgenic plant cell, said method comprising expressing in said transgenic plant cell a hexokinase nucleic acid sequence that specifically hybridizes under highly stringent conditions to the complement of the sequence set forth in SEQ ID NO.:

• 3 or SEQ ID NO.:
• 4, wherein said highly stringent conditions comprise
• a) hybridization at 65° C. and 50% formamide,
• b) a first wash at 65° C., 2×SSC, and 1% SDS, and
• c) a second wash at 65° C., 1×SSC, and 0.1% SDS;
• and said nucleic acid encodes a hexokinase protein comprising a sugar binding domain, wherein expression of said hexokinase nucleic acid sequence increases the level of said hexokinase protein in said transgenic plant cell.