Claudel Cyrille, Lev-Yadun Simcha
Institute for Plant Science and Microbiology, Department of Biology, University of Hamburg, Hamburg, Germany.
Department of Biology & Environment, Faculty of Natural Sciences, University of Haifa-Oranim, Tivon, Israel.
Plant Signal Behav. 2021 Dec 2;16(12):1991712. doi: 10.1080/15592324.2021.1991712. Epub 2021 Nov 28.
Some plant lineages, such as Araceae and Orchidaceae, have independently evolved deceptive flowers. These exploit the insect's perception and deceive the insects into believing to have located a suitable opportunity for reproduction. The scent compounds emitted by the flowers are the key signals that dupe the insects, guiding them to the right spots that in turn ensure flower pollination. Most species of the genus of the Araceae emit scent compounds that are characteristic of a deceit, suggesting a specific plant pollinator interaction and according odors. However, only a few clear evolutionary trends in regard to inflorescence odors in could be traced in previous studies - an intriguing result, considered the multitude of characteristic scent compounds expressed in as well as the key function of scent compounds in deceptive floral systems in general. At least two factors could account for this result. (1) The deceptive pollinator-attraction floral system, including the emitted scent compounds, is less specific than assumed. (2) An evolutionary trend cannot be discerned if the intraspecific scent variation (odor polymorphism) exceeds the interspecific odor variation. Therefore, we discuss the potential deceptive function of the emitted scent compounds, in particular those that are related to cadaveric decomposition. Moreover, we review the data about emitted scent compounds in with a focus on putative odor polymorphism. Upon examination, it appears that the emitted scent compounds in are highly mimetic of decomposing organic materials. We show that several species display odor polymorphism, which in turn might constitute an obstacle in the analysis of evolutionary trends. An important odor polymorphism is also indicated by subjective odor perceptions. Odor polymorphism may serve several purposes: it might represent an adaptation to local pollinators or it might assumingly prevent insects from learning to distinguish between a real decomposing substrate and an oviposition-site mimic.
一些植物谱系，如天南星科和兰科，已经独立进化出了欺骗性花朵。这些花朵利用昆虫的感知能力，诱使昆虫误以为找到了合适的繁殖机会。花朵释放的气味化合物是欺骗昆虫的关键信号，引导它们找到正确的位置，从而确保花朵授粉。天南星科的大多数物种释放出具有欺骗特征的气味化合物，这表明存在特定的植物-传粉者相互作用以及相应的气味。然而，在先前的研究中，关于天南星科花序气味，只能追溯到少数几个明确的进化趋势——这是一个有趣的结果，考虑到天南星科中表达的大量特征性气味化合物以及气味化合物在一般欺骗性花卉系统中的关键作用。至少有两个因素可以解释这一结果。（1）包括释放的气味化合物在内的欺骗性传粉者吸引花卉系统，其特异性低于预期。（2）如果种内气味变异（气味多态性）超过种间气味变异，就无法识别进化趋势。因此，我们讨论了释放的气味化合物的潜在欺骗功能，特别是那些与尸体分解相关的化合物。此外，我们回顾了关于天南星科释放的气味化合物的数据，重点关注假定的气味多态性。经研究发现，天南星科释放的气味化合物与分解的有机物质高度相似。我们表明，几个物种表现出气味多态性，这反过来可能构成分析进化趋势的障碍。主观气味感知也表明存在重要的气味多态性。气味多态性可能有多种用途：它可能代表对当地传粉者的一种适应，或者可能假定可以防止昆虫学会区分真正的分解底物和产卵场所模拟物。
