Extraction and quantitation of leaf and sepal chlorophyll. Weighted 1 g fresh
sepals of B17 and B114 fruits of wild-type and transgenic lines, pounded to pieces
with liquid nitrogen, extracted with 10 ml mixed solution acetone and ethanol (251,
V/V) for 48 h in dark, centrifuged 5000 rpm for 10 min at 4uC. The absorbance of the
supernatant was measured at 645 and 663 nm in a PerkinElmer Lambda 900 UV/
VIS/NIR spectrophotometer using above-mentioned mixed solution as a blank. Total
chlorophyll content were calculated using the formulas according to the method of
Arnon60: Chl (mg/g) 5 20.29A645 1 8.02A663. The chlorophyll of each sample was
extracted and measured in triplicate. Chlorophyll contents of mature leaves, treated
by ethylene/air were measured using the same method.