Carotenoid Accumulation and Carotenogenic Genes Expression During Two Types of Persimmon Fruit (Diospyros kaki L.) Development

Abstract

Persimmon (Diospyros kaki L.), belonging to the Ebenaceae family, has been used not only as a fresh fruit, but also for many medicinal uses. Carotenoids are the main pigment in persimmon fruit, which contribute significantly to fruit color and nutritional quality due to their composition and content. In this study, fruit quality indices, carotenoid contents and expression of carotenogenic genes were analyzed in two types of persimmon fruit. The results demonstrated that there was a positive correlation between fruit color and the contents of main composition and total carotenoids. Carotenoid accumulation in persimmon fruit resulted from the interaction of carotenogenic genes, but the molecular mechanisms responsible for accumulation of carotenoids in two types of persimmon fruit had a few differences. As a complete unit, the relatively low expression level of phytoene synthase gene (DkPSY) in "Niuxinshi" resulted in low carotenoid contents or even under the detection limit at the early fruit developmental stages; but low carotenoid contents in "Nishimurawase" were due to the relatively low expression level of carotenogenic genes other than DkPSY. At the late fruit developmental stages, increased expression levels of DkPSY, phytoene desaturase gene and beta-carotene hydroxylase gene (DkBCH) induced elevated carotenoid contents; because all carotenogenic genes strongly expressed in "Nishimurawase", a large amount of carotenoids were accumulated. In addition, β-cryptoxanthin was the main composition whose content increased with the fruit maturity changes, which was mainly because of DkBCH which might lead more conversion of β-carotene to β-cryptoxanthin.

Transcriptome sequencing of a chimaera reveals coordinated expression of anthocyanin biosynthetic genes mediating yellow formation in herbaceous peony (Paeonia lactiflora Pall.)

“…On the other hand, flower colours were expressed as L * , a * and b * . In a uniform colour space, L * represented lightness, a * represented the ratio of red/magenta and green, and b * represented the ratio of yellow and blue [25]. In four different developmental stages, L * values of the outer-petal and inner-petal were all gradually increased which was always lower in the outer-petal compared to the inner-petal; however, the b * value of the outer-petal and a * value of the inner-petal decreased, which all tended to zero.…”

Analysis of Main Quality Characteristics of Persimmon (Diospyros Kaki L.) Fruits.

“…b* value trended similarly with L* value, which revealed that the fruit color was yellow and gradually deepening, and C* also represented the lightness which trended similarly with L* value. [29]. In addition, the color was well described by a*/b* ratio which was negative for green fruits, zero for yellow fruits, and positive for orange fruits [30].…”

“…Alternatively, the color also could be depicted by H° as follows: 0° for reddish-purple, 90° for yellow, 180° for bluish-green and 270° for blue [31,32]. These two values all showed that the fruit color of both "Niuxinshi" and "Nishimurawase" changed from green to yellow, and "Nishimurawase" was more evident [29]. In "Pingxiangli" pear hue angle decreased during fruit ripening.…”

Young Persimmon Ingestion Suppresses Lipid Oxidation in Rats

“…Zhao et al reported that total carotenoid levels in mature persimmon are higher than in young persimmon (24). The maximum content of total carotenoid they analyzed was around 100 g/100 g wet weight of mature persimmon.…”