Miller Rebecca E, Jensen Rigel, Woodrow Ian E
School of Botany, The University of Melbourne, Victoria, 3010, Australia.
Ann Bot. 2006 Jun;97(6):1017-44. doi: 10.1093/aob/mcl048. Epub 2006 Mar 6.
Plant cyanogenesis is the release of toxic cyanide from endogenous cyanide-containing compounds, typically cyanogenic glycosides. Despite a large body of phytochemical, taxonomic and ecological work on cyanogenic species, little is known of their frequency in natural plant communities. This study aimed to investigate the frequency of cyanogenesis in Australian tropical rainforests. Secondary aims were to quantify the cyanogenic glycoside content of tissues, to investigate intra-plant and intra-population variation in cyanogenic glycoside concentration and to appraise the potential chemotaxonomic significance of any findings in relation to the distribution of cyanogenesis in related taxa.
All species in six 200 m(2) plots at each of five sites across lowland, upland and highland tropical rainforest were screened for cyanogenesis using Feigl-Anger indicator papers. The concentrations of cyanogenic glycosides were accurately determined for all cyanogenic individuals.
Over 400 species from 87 plant families were screened. Overall, 18 species (4.5 %) were cyanogenic, accounting for 7.3 % of total stem basal area. Cyanogenesis has not previously been reported for 17 of the 18 species, 13 of which are endemic to Australia. Several species belong to plant families or orders in which cyanogenesis has been little reported, if at all (e.g. Elaeocarpaceae, Myrsinaceae, Araliaceae and Lamiaceae). A number of species contained concentrations of cyanogenic glycosides among the highest ever reported for mature leaves-up to 5.2 mg CN g(-1) d. wt, for example, in leaves of Elaeocarpus sericopetalus. There was significant variation in cyanogenic glycoside concentration within individuals; young leaves and reproductive tissues typically had higher cyanogen content. In addition, there was substantial variation in cyanogenic glycoside content within populations of single species.
This study expands the limited knowledge of the frequency of cyanogenesis in natural plant communities, includes novel reports of cyanogenesis among a range of taxa and characterizes patterns in intra-plant and intra-population variation of cyanogensis.
植物生氰作用是指从内源性含氰化合物（通常是生氰糖苷）中释放出有毒的氰化物。尽管对生氰物种进行了大量的植物化学、分类学和生态学研究，但对于它们在天然植物群落中的出现频率却知之甚少。本研究旨在调查澳大利亚热带雨林中生氰作用的频率。次要目的是量化组织中生氰糖苷的含量，研究植物内部和种群内部生氰糖苷浓度的变化，并评估与相关类群中生氰作用分布相关的任何发现的潜在化学分类学意义。
在低地、高地和山地热带雨林的五个地点，每个地点的六个200平方米样地中的所有物种，都使用费格尔 - 安格尔试纸进行生氰作用筛选。对所有生氰个体准确测定生氰糖苷的浓度。
对来自87个植物科的400多种植物进行了筛选。总体而言，18种植物（4.5%）具有生氰能力，占总茎基部面积的7.3%。这18种植物中有17种此前未报道过有生氰作用，其中13种是澳大利亚特有种。有几个物种属于很少报道（如果有报道的话）生氰作用的植物科或目（如杜英科、紫金牛科、五加科和唇形科）。一些物种成熟叶片中的生氰糖苷浓度是有史以来报道的最高浓度之一——例如，绢毛杜英（Elaeocarpus sericopetalus）的叶片中高达5.2毫克氰/克干重。个体内部生氰糖苷浓度存在显著差异；幼叶和生殖组织的氰含量通常较高。此外，单一物种的种群内部生氰糖苷含量也存在很大差异。
本研究扩展了我们对天然植物群落中生氰作用频率的有限认识，包括一系列类群中生氰作用的新报道，并描述了植物内部和种群内部生氰作用的变化模式。
