Kwanok, Fujisaka #5, Paldal, and Suwon #82 as japonica type and IR-262 and CP-slo as indica type of rice seeds were selected for this experiment among varieties grown in Korea. Activities of crude enzymes extracted from germinating seeds of these varieties on malathion and p-nitrophenyl acetate as substrates, esterase zymograms with 1-naphthyl acetate as substrate, and some observations are summarized as follows:
1. Activities per unit volume of crude enzyme preparations on malathion were in the order of Kwanok$gt;IR-262$gt; Fujisaka #5$gt; CP-slo$gt;Paldal$gt;Suwon #82.
2. Esterase zymograms on agar-gel electrophoretograms exhibited three to four bands two electrodes with little difference among varieties, nevertheless showing a wide and strongly-colored band toward cathode. Suwon #82 has a somewhat different pattern from others.
3. Enzyme activities per milligram protein with p-nitrophenyl acetate as substrate were in the order of CP-slo$gt;IR-262$gt;Paldal$gt;Kwanok$gt;Suwon #82$gt;Fujisaka #5, indicating that activities of indica type are much stronger than those of japonica type, but not in agreement with results with malathion.
4. Malathion did not much inhibit the esterase activity at the concentration of 0.2PPM on electrophoretograms.
5. It is supposed that there is a complex esterase system hydrolyzing malathion and p-nitrophenyl acetate in germinating rice seeds
|