Nepenthes insignis uses a C2-portion of the carbon skeleton of L-alanine acquired via its carnivorous organs, to build up the allelochemical plumbagin
Nepenthes insignis uses a C2-portion of the carbon skeleton of L-alanine acquired via its carnivorous organs, to build up the allelochemical plumbagin
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DOI：
10.1016/s0031-9422(02)00003-1
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发表时间：
2002-03-01
期刊：
影响因子：
3.8
通讯作者：
Bringmann, G
中科院分区：
文献类型：
--
作者：
Rischer, H;Hamm, A;Bringmann, G
热带猪笼草（Nepenthes）用它们特殊的杯状叶子捕捉动物，通过分泌酶消化猎物，并积极吸收产生的化合物。这种行为的好处是能够在营养匮乏的栖息地生长和竞争。我们目前的体外研究表明，植物不仅利用了提供给食肉器官的丙氨酸的氮，而且还利用了来自稳定同位素标记为l -丙氨酸的C-2和C-3的完整C-2单元作为构建单元，例如用于合成次生代谢物铅白金素，这是一种有效的化感化学物质。这一结果为植物食肉性的益处增加了一个新的方面。从头合成的白桦素的可用性可能增强了植物防御植噬和致病生物的适应性。缺乏特定的摄取或辅酶A激活机制可能是投喂给猪笼草的醋酸酯没有被纳入萘醌白丹素的原因。相比之下，首次从猪笼草中分离到的二氢萘醌类糖苷rossoliside和plumbaside A在喂食这两种前体后均未掺入，这表明这些化合物可能是具有极低周转率的储存形式。(C) 2002 Elsevier Science Ltd.版权所有。
Tropical pitcher plants (Nepenthes) catch animals in their specialized cup-shaped leaves, digest the prey by secreting enzymes, and actively take up the resulting compounds, The benefit of this behaviour is the ability to grow and compete in nutrient-poor habitats. Our present in vitro study shows that not only the nitrogen of alanine fed to the carnivorous organs is used by the plant but that in addition intact C-2-units derived from C-2 and C-3 of stable isotope labelled L-alanine serve as building blocks, here exemplarily for the synthesis of the secondary metabolite plumbagin, a potent allelochemical. This result adds a new facet to the benefit of carnivory for plants. The availability of plumbagin by a de novo synthesis probably enhances the plants' fitness in their defence against phytophagous and pathogenic organisms. A missing specific uptake or CoA activation mechanism might be the reason that acetate fed to the pitchers was not incorporated into the naphthoquinone plumbagin. The dihydronaphthoquinone glucosides rossoliside and plumbaside A, here isolated for the first time from Nepenthes, by contrast, showed no incorporation after feeding of any of the two precursors, suggesting these compounds to be storage forms with probably very low turnover rates. (C) 2002 Elsevier Science Ltd. All rights reserved.