A CHROMOPLAST-SPECIFIC PROTEIN IN CAPSICUM-ANNUUM - CHARACTERIZATION AND EXPRESSION OF THE CORRESPONDING GENE

We have isolated cDNA and genomic clones corresponding to a gene highl y and specifically expressed at the late stage of fruit-ripening in be ll-pepper. Antibodies raised against the expressed protein allowed det ermination of the cellular localization of the gene product. The encod ed protein is present only in chromoplasts from fully-ripe red fruits, as shown by Western analysis and import experiments. The correspondin g mRNA accumulates to high levels during ripening at orange and red st ages, but is not detected in yellow varieties impaired in the synthesi s of ketocarotenoids. Several lines of evidence indicate that the enco ded protein is an oxido-reductase involved in the synthesis of capsant hin and capsorubin.