Post‐secretory synthesis of a natural analog of iron‐gall ink in the black nectar of Melianthus spp.
Post‐secretory synthesis of a natural analog of iron‐gall ink in the black nectar of Melianthus spp.
复制标题
在Melianthus spp 的黑色花蜜中进行铁的天然类似物五倍子墨水的后分泌合成。
DOI：
10.1111/nph.18859
复制
发表时间：
2023
期刊：
影响因子：
9.4
通讯作者：
Carter, Clay J.
中科院分区：
文献类型：
--
作者：
Magner, Evin T.;Roy, Rahul;Freund Saxhaug, Katrina;Zambre, Amod;Bruns, Kaitlyn;Snell‐Rood, Emilie C.;Hampton, Marshall;Hegeman, Adrian D.;Carter, Clay J.
Melianthusflowers产生的黑色花蜜被认为是鸟类传粉者的视觉引诱剂，但黑色色素的化学身份和合成尚不清楚。分析生物化学，转录组学，蛋白质组学和酶测定的组合被用来鉴定赋予Melianthusnectar黑色的色素及其合成方式。视觉建模的传粉者也被用来推断一个潜在的功能的黑色coloring.High浓度的鞣花酸和铁给花蜜的深黑色的颜色，这可以通过只含有鞣花酸和铁（iii）的合成溶液重演。花蜜中还含有一种过氧化物酶，可以氧化没食子酸形成鞣花酸。在体外，含有花蜜过氧化物酶、没食子酸、过氧化氢和铁（iii）的反应完全重现了花蜜的黑色。视觉建模表明，在花的背景下，黑色对鸟类传粉者来说非常显眼。Melianthusnectar含有铁胆墨水的天然类似物，人类至少从中世纪开始使用。这种色素来源于花蜜中合成的鞣花酸-铁复合物，可能与吸引南部非洲特有的雀形目传粉者有关。
The black nectar produced byMelianthusflowers is thought to serve as a visual attractant to bird pollinators, but the chemical identity and synthesis of the black pigment are unknown.A combination of analytical biochemistry, transcriptomics, proteomics, and enzyme assays was used to identify the pigment that givesMelianthusnectar its black color and how it is synthesized. Visual modeling of pollinators was also used to infer a potential function of the black coloration.High concentrations of ellagic acid and iron give the nectar its dark black color, which can be recapitulated through synthetic solutions containing only ellagic acid and iron(iii). The nectar also contains a peroxidase that oxidizes gallic acid to form ellagic acid.In vitroreactions containing the nectar peroxidase, gallic acid, hydrogen peroxide, and iron(iii) fully recreate the black color of the nectar. Visual modeling indicates that the black color is highly conspicuous to avian pollinators within the context of the flower.Melianthusnectar contains a natural analog of iron‐gall ink, which humans have used since at least medieval times. This pigment is derived from an ellagic acid‐Fe complex synthesized in the nectar and is likely involved in the attraction of passerine pollinators endemic to southern Africa.