The Tomato Juhwang Mutant Accumulates a High Level of beta-Carotene and has a Long Shelf-Life

摘要

Carotenoids have diverse functions in plants and animals. In tomato (Solanum lycopersicum), the red color of fruits is due to the accumulation of the carotenoid lycopene during fruit ripening. Here, the effect of a new recessive mutation juhwang (jh) on fruit color and shelf life was investigated during fruit ripening. The prominent phenotype of jh plants was orange fruit color. Carotenoid analysis revealed that jh fruits had lower lycopene and higher beta-carotene levels than those in wild-type fruits after the fruit ripening stage. Expression analysis of carotenoid biosynthetic genes showed that the gene encoding lycopene-epsilon-cyclase was upregulated and the beta-carotene hydroxylase 2 gene was significantly downregulated in jh fruits compared with those in wild-type fruits during ripening. jh fruits also had a longer shelf-life than that of wild-type fruits based on the increased firmness. The gene expression patterns and levels of 1-aminocyclopropane-1-carboxylic acid synthases, pectate lyase, and polygalacturonase, which are fruit ripening and cell wall-softening-related genes, were delayed and reduced in jh fruits during fruit ripening compared with those in wild-type fruits. Therefore, jh may represent a novel gene, and these plants may serve as an important genetic resource to study fruit ripening related to carotenoids and shelf-life.