The SAMase gene encodes S-adenosylmethionine (SAM) hydrolase which
is capable of degrading and thus reducing SAM. The conversion of
SAM to 1-aminocyclopropane-1-carboxylic acid (ACC) is the first
step in ethylene biosynthesis and the lack of sufficient pools of
SAM results in significantly reduced synthesis of this
phytohormone, which is known to play a key role in fruit ripening.