Spontaneous mutations in fruit‐specific carotenoid biosynthetic genes of tomato (Solanum lycopersicum) have led to improved understanding of ripening‐associated carotenogenesis. Here, we confirm that ZDS is encoded by a single gene in tomato transcriptionally regulated by ripening transcription factors RIN, NOR and ethylene. Manipulation of ZDS was achieved through transgenic repression and heterologous over‐expression in tomato. CaMV 35S‐driven RNAi repression inhibited carotenoid biosynthesis in all aerial tissues examined resulting in elevated levels of ζ‐carotene isomers and upstream carotenoids, while downstream all trans‐lycopene and subsequent photoprotective carotenes and xanthophylls were diminished. Consequently, immature fruit displayed photo‐bleaching consistent with reduced levels of the photoprotective carotenes and developmental phenotypes related to a reduction in the carotenoid‐derived phytohormone abscisic acid (ABA). ZDS‐repressed ripe fruit was devoid of the characteristic red carotenoid, all trans‐lycopene and displayed brilliant yellow pigmentation due to elevated 9,9′ di‐cis‐ζ‐carotene. Over‐expression of the Arabidopsis thaliana ZDS (AtZDS) gene bypassed endogenous co‐suppression and revealed ZDS as an additional bottleneck in ripening‐associated carotenogenesis of tomato. Quantitation of carotenoids in addition to multiple ripening parameters in ZDS‐altered lines and ABA‐deficient fruit‐specific carotenoid mutants was used to separate phenotypic consequences of ABA from other effects of ZDS manipulation and reveal a unique and dynamic ζ‐carotene isomer profile in ripe fruit.

中文翻译：

---

番茄中ZDS的处理暴露了类胡萝卜素和ABA对果实发育和成熟的特异性作用。

番茄果实特异性类胡萝卜素生物合成基因（Solanum lycopersicum）的自发突变导致人们对与成熟相关的类胡萝卜素生成有了更深入的了解。在这里，我们确认ZDS由番茄中的单个基因编码，该基因受成熟的转录因子RIN，NOR和乙烯转录调控。ZDS的操纵是通过转基因抑制和异源过表达实现的。CaMV 35S驱动的RNAi抑制抑制了所检查的所有气生组织中的类胡萝卜素生物合成，导致ζ-胡萝卜素异构体和上游类胡萝卜素水平升高，而下游的所有反式番茄红素以及随后的光保护性胡萝卜素和叶黄素都减少了。因此，未成熟的果实显示出光漂白，这与减少的光保护性胡萝卜素水平和与减少类胡萝卜素的植物激素脱落酸（ABA）有关的发育表型一致。ZDS抑制的成熟果实不含特征性的红色类胡萝卜素，全透明番茄红素，并且由于升高的9,9'di -cis-ζ-胡萝卜素而显示出鲜艳的黄色色素沉着。拟南芥ZDS（AtZDS）的过表达）基因绕过了内源性共抑制，并揭示了ZDS是番茄成熟相关的胡萝卜素形成中的另一个瓶颈。在ZDS改变品系和ABA缺乏的水果特异类胡萝卜素突变体中，除了多个成熟参数外，还对类胡萝卜素进行定量分析，以将ABA的表型后果与ZDS操纵的其他作用区分开来，并揭示了成熟中独特且动态的ζ-胡萝卜素异构体图谱水果。