Farré-Armengol Gerard, Filella Iolanda, Llusià Joan, Peñuelas Josep
CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain.
CREAF, Cerdanyola del Vallès, 08193 Barcelona, Catalonia, Spain.
Molecules. 2017 Jul 13;22(7):1148. doi: 10.3390/molecules22071148.
β-Ocimene is a very common plant volatile released in important amounts from the leaves and flowers of many plant species. This acyclic monoterpene can play several biological functions in plants, by potentially affecting floral visitors and also by mediating defensive responses to herbivory. The ubiquity and high relative abundance of β-ocimene in the floral scents of species from most plant families and from different pollination syndromes (ranging from generalism to specialism) strongly suggest that this terpenoid may play an important role in the attraction of pollinators to flowers. We compiled abundant evidence from published studies that supports β-ocimene as a generalist attractant of a wide spectrum of pollinators. We found no studies testing behavioural responses of pollinators to β-ocimene, that could directly demonstrate or deny the function of β-ocimene in pollinator attraction; but several case studies support that the emissions of β-ocimene in flowers of different species follow marked temporal and spatial patterns of emission, which are typical from floral volatile organic compound (VOC) emissions that are involved in pollinator attraction. Furthermore, important β-ocimene emissions are induced from vegetative plant tissues after herbivory in many species, which have relevant functions in the establishment of tritrophic interactions. We thus conclude that β-ocimene is a key plant volatile with multiple relevant functions in plants, depending on the organ and the time of emission. Experimental behavioural studies on pure β-ocimene conducted with pollinating insects will be necessary to prove the assumptions made here.
β-罗勒烯是一种非常常见的植物挥发物，许多植物种类的叶子和花朵都会大量释放这种物质。这种无环单萜在植物中可发挥多种生物学功能，它可能会影响访花者，还能介导植物对食草动物的防御反应。在大多数植物科以及不同授粉综合征（从泛化授粉到特化授粉）的植物花香中，β-罗勒烯普遍存在且相对含量较高，这有力地表明这种萜类化合物可能在吸引传粉者到花朵方面发挥重要作用。我们从已发表的研究中收集了大量证据，这些证据支持β-罗勒烯是多种传粉者的通用引诱剂。我们没有找到测试传粉者对β-罗勒烯行为反应的研究，这些研究可以直接证明或否定β-罗勒烯在吸引传粉者方面的作用；但一些案例研究表明，不同物种花朵中β-罗勒烯的释放遵循明显的时间和空间模式，这是参与吸引传粉者的花香挥发性有机化合物（VOC）释放的典型特征。此外，在许多物种中，食草动物啃食后，植物营养组织会诱导产生重要的β-罗勒烯排放，这在建立三级营养相互作用中具有相关功能。因此，我们得出结论，β-罗勒烯是一种关键的植物挥发物，在植物中具有多种相关功能，这取决于其释放的器官和时间。有必要对传粉昆虫进行关于纯β-罗勒烯的实验行为研究，以验证此处提出的假设。
