作者：Cao HB, Zhang JC, Xu JD, Ye JL, Yun Z, Xu Q, Xu J, Deng XX.
作者单位：Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, China
摘要：Citrus fruits, which exhibit extensive diversity of carotenoid patterns, can serve as a unique system to improve the understanding of carotenogenesis. Herein, we engineered embryogenic calli from four citrus genotypes as engineered cell models (ECMs) by overexpressing a bacterial phytoene synthase gene (CrtB). Ripe flavedos (the colored outer layer of citrus fruits) were offered as a comparative system to the ECMs. In the ECMs, carotenoid patterns showed diversity depending on the genotypes and produced additional carotenoids, such as lycopene, that were absent from the wild-type lines. However, the carotenoid pattern in the ECMs of one genotype seems not to correlate with that in its flavedo. In the ECMs, there emerged a favored β,β-pathway characterized by a striking accumulation of β-carotene, which was dramatically unique from those in the wild-type calli and ripe flavedos. Unlike flavedos that contained a typical chromoplast development, the ECMs sequestered most carotenoids in the amyloplasts in crystal form, which led the amyloplast morphology to show chromoplast-like profile. Transcriptional analysis revealed a markedly flavedo-specific expression of β-carotene hydroxylase gene (HYD), which was suppressed in the calli. Coexpression of CrtB and HYD in the ECMs confirmed that HYD predominantly mediated the preferred carotenoid patterns between the ECMs and flavedos, and also revealed that the carotenoid crystals in the ECMs were majorly composed of β-carotene.
文献注录：Cao HB, Zhang JC, Xu JD, Ye JL, Yun Z, Xu Q, Xu J, Deng XX.. Comprehending crystalline β-carotene accumulation by comparing engineered cell models and natural carotenoid-rich system of citrus [A]. [C] Ⅶ International Citrus Congress. 2012.
报/刊名：《》，发表于2012
文献类型： [A]
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