Regulation of PG mRNA, enzyme activity, and
protein accumulation by time of ethylene treatment. MG transgenic ACC
synthase antisense tomato fruits were treated with 10 μL/L ethylene
for the indicated times, and PG mRNA, enzyme activity, and protein
levels were determined. A, mRNA-hybridization analysis. Each lane
contained 3 μg of poly(A+) mRNA. B, PG enzyme assays were
performed by incubating 10 mg of crude cell wall protein extracts with
polygalacturonic acid, and PG activity was determined by a reducing
sugar assay. C, Immunoblot of cell wall protein extracts. Each lane
contained 10 mg of protein, and PG protein was detected with antibody
by using a chemiluminescence kit. PG2 indicates the mobility of
purified PG.