Characterization of prolycopene-accumulated Tan mutant of .

Significant progress has been made in understanding carotenoid biosynthesis in tomato (), and most pathway genes have been cloned and characterized. However, isolation and characterization of novel fruit ripening mutants is a continuous and essential process. This study describes the characterization of the Tan (Tangerine) mutant of . Fruits of Tan-mutant plants have a unique orange color and accumulate prolycopene instead of lycopene. Genetic analysis revealed that a monogenic recessive mutation affects fruit pigmentation in the mutant, which inhibits the conversion of prolycopene to lycopene. Further, molecular analysis indicates that fruit phenotype is attributed to loss of gene function, which encodes a carotenoid isomerase enzyme that converts prolycopene to lycopene. The loss of gene function is due to the deletion of 406 bp from the promoter region. Analysis of genome-wide transcriptome expression profiling identified several hundreds of differentially expressed genes in the fruit ripening stages. The results of microarray studies showed a tendency for upregulation of the genes at the mature green stage and downregulation at the fully ripened stage in the mutant. The isolated mutant can be used for the development of varieties having altered nutritional value.