Metsulfuron-methyl 처리시 옥수수에 발현되는 자색화의 원인을 알아보기 위하여 제반실험을 수행하였다. Metsulfuron-methyl 처리시 농도와 시간에 의존하여 당과 anthocyanin의 함량이 증가되었고, 증가된 anthocyanin은 ILE+VAL이나 DCMU 처리에 의해서 경감되었다. 당을 외부로부터 공급하였을 때 당 농도에 의존하여 anthocyanin 함량이 증가되었고, 당형성이 제한되어 있는 백화조직에서는 metsulfuron-methyl 처리로 anthocyanin 생성이 증가되지 않았다. 그리고 metsulfuron-methyl은 광합성 자체를 억제하지 않았다. Metsulfuron-methyl에 의한 anthocyanin 축적을 구조 유전자 변이주 모두에서는 관찰할 수 없었고, 조절유전자 변이주 중에서는 R-r, r-r에서만 anthocyanin축적을 관찰할 수 있었다. 이들의 제반 결과는 metsulfuron-methyl이 처리되면 광합성 산물인 당이 축적되고, 이는 anthocyanin 생합성 과정에 관련된 유전자를 자극함으로써 anthocyanin 생합성과정을 활성화시키며 이로 인해 옥수수가 자색화됨을 시사해 준다.
The objective of this study was to investigate the cause of anthocyanin accumulation in the corn leaves treated with metsulfuron-methyl. The accumulation of anthocyanin and total sugar was increased with the time after metsulfuron-methyl application and with the greater herbicide concentration as well. The anthocyanin increase was alleviated by the combined treatment of DUMU or the tank-mixture treatment of metsulfuron-methyl, isoleucine and valine. Metsulfuron-methyl could not enhance the anthocyanin formation in the nonchlorophyllous tissue in which photosynthetic carbohydrate production was limited. Upon the exogenous supply of sucrose, however, the contents of anthocyanin was increased in the both chlorophyllous and nonchlorophyllous leaf segment of corn without the herbicide treatment. On the other hand, the herbicide itself did not influence Hill reaction in vitro and photosynthesis electron transport in vivo. The anthocyanin accumulation by metsulfitronmethyl did not occur in the corn mutants deficient in the structural gene of anthocyanin synthesis, but corns deficient in the regulatory gene had the anthocyanin accumulation only in R-r and r-r type. The above results suggest that the purple pigmentation in the corn leaves treated with metsulfuron-methyl is related to the accumulation of photosynthetic carbohydrate which can stimulate the. regulatory gene related to anthocyanin biosynthetic pathway.
