Clivia miniata is renowned for its evergreen and strap-like leaves, whereas its floral color and scent are lacking of diversity. Presently, anthocyanin, volatile terpene and carotenoid metabolisms were integrally investigated in C. miniata flowers. As results, pelargonidins and lutein might cooperate together to confer orange or yellow color to C. miniata flowers, and only trace amount of (+)-limonene was detected. The expression levels of CmF3′H and CmDFR appeared to be responsible for the ratio of cyanidin and pelargonidin derivatives in C. miniata, and the low expression of CmF3′H was responsible for the lack of cyanidins in flowers. Moreover, CmF3′H promoter could not be activated by CmMYBAs, suggesting that it was controlled by novel regulators. Only two CmTPSs were functional with CmTPS2 responsible for (+)-limonene synthesis, contributing to the monotonous flower volatile terpenes of C. miniata. CmCCD1a and CmCCD1b were able to cleave carotenoids at 5, 6 (5′, 6′) and 9, 10 (9′, 10′) positions to generate volatile apocarotenoids, whereas the low-quantified substrates or specific subcellular localizations of CmCCD1s might constrain volatile apocarotenoids release. Consequently, activating F3’H, introducing novel F3’5’H or versatile TPS may be effective ways to modify the floral color and scent, respectively. Alternatively, modifying the carotenoid flux or CCD1 localization might affect floral color and scent simultaneously. As a whole, the present study preliminarily deciphered the genetic constraints underlying flower color, scent developments and proposed possible schemes for further genetic modification of ornamental traits in C. miniata and other plants.

中文翻译：

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花色和香味的生化和分子研究为君子兰观赏性状的进一步遗传改造提供了线索


君子兰以其常绿、带状的叶子而闻名，但其花色和香味缺乏多样性。目前，对C. miniata花中的花色苷、挥发性萜烯和类胡萝卜素代谢进行了综合研究。结果，天竺葵素和叶黄素可能共同赋予天竺葵花橙色或黄色，并且仅检测到微量的(+)-柠檬烯。 CmF3'H 和 CmDFR 的表达水平似乎与 C. miniata 中矢车菊素和天竺葵素衍生物的比例有关，而 CmF3'H 的低表达是导致花中矢车菊素缺乏的原因。此外，CmF3'H启动子不能被CmMYBAs激活，表明它是由新的调控因子控制的。只有两个 CmTPS 具有功能，其中 CmTPS2 负责 (+)-柠檬烯合成，从而形成了 C. miniata 的单调花挥发性萜烯。 CmCCD1a 和 CmCCD1b 能够在 5, 6 (5', 6') 和 9, 10 (9', 10') 位置裂解类胡萝卜素以产生挥发性类胡萝卜素，而 CmCCD1s 的低定量底物或特定的亚细胞定位可能会限制挥发性类胡萝卜素释放。因此，激活F3'H、引入新颖的F3'5'H或多功能TPS可能分别是改变花色和香味的有效方法。或者，改变类胡萝卜素通量或 CCD1 定位可能会同时影响花的颜色和气味。总体而言，本研究初步破译了花色、气味发育的遗传约束，并提出了进一步对 C. miniata 和其他植物观赏性状进行遗传改造的可能方案。