School of Agriculture and Environment, Massey University, Tennent Drive, Palmerston North 4474, New Zealand.
Manaaki Whenua - Landcare Research, Riddet Road, Massey University, Palmerston North 4474, New Zealand.
Molecules. 2020 Jul 13;25(14):3200. doi: 10.3390/molecules25143200.
(heather) is an aggressive invasive weed on the Central Plateau, North Is., New Zealand (NZ), where it encounters different environmental factors compared to its native range in Europe, such as high ultraviolet radiation (UV) and a lack of specialist herbivores. The specialist herbivore (heather beetle) was introduced from the United Kingdom (UK) in 1996 as a biocontrol agent to manage this invasive weed. Like other plant invaders, a novel environment may be challenging for heather as it adjusts to its new conditions. This process of "adjustment" involves morphological and physiological changes often linked to phenotypic plasticity. The biochemical responses of exotic plants to environmental variables in their invaded range is poorly understood. The production and release of volatile organic compounds (VOCs) is essential to plant communication and highly susceptible to environmental change. This study therefore aimed to explore the VOC emissions of heather in response to different levels of UV exposure, and to feeding damage by . Using tunnel houses clad with UV-selective filters, we measured VOCs produced by heather under NZ ambient, 20% attenuated, and 95% attenuated solar UV treatments. We also compared VOC emissions in the field at adjacent sites where was present or absent. Volatiles produced by the same target heather plants were measured at four different times in the spring and summer of 2018-2019, reflecting variations in beetle's abundance, feeding stage and plant phenology. Heather plants under 95% attenuated UV produced significantly higher amounts of ()-β-farnesene, decanal, benzaldehyde, and benzeneacetaldehyde compared to 25% attenuated and ambient UV radiation. We also found significant differences in volatiles produced by heather plants in beetle-present versus beetle-absent sites on most sampling occasions. We also recorded a lower number of generalist herbivores on heather at sites where was present. Interactions between invasive plants, a novel environment, and the native communities they invade, are discussed.
（石南花）是新西兰北岛中央高原上一种具有侵略性的入侵杂草，与原产于欧洲的环境因素不同，例如高紫外线辐射（UV）和缺乏专门的食草动物。1996 年，作为生物防治剂，一种专门的食草动物（石南花甲虫）从英国（UK）引入，以管理这种入侵杂草。与其他植物入侵者一样，石南花可能会发现新环境具有挑战性，因为它需要适应新的条件。这个“调整”过程涉及到形态和生理变化，通常与表型可塑性有关。外来植物对入侵地区环境变量的生化反应还知之甚少。挥发性有机化合物（VOCs）的产生和释放对植物的交流至关重要，而且极易受到环境变化的影响。因此，本研究旨在探索石南花对不同水平的紫外线照射和 的取食损伤的 VOC 排放。我们使用带有紫外线选择性过滤器的隧道房屋，测量了石南花在新西兰环境、紫外线衰减 20%和紫外线衰减 95%的条件下产生的 VOC。我们还比较了在相邻有或没有 的地点实地测量的 VOC 排放。在 2018-2019 年的春季和夏季，我们在四个不同的时间测量了同一种目标石南花产生的挥发物，反映了甲虫数量、取食阶段和植物物候的变化。与紫外线衰减 25%和环境紫外线辐射相比，在紫外线衰减 95%的条件下，石南花产生的 ()-β-法尼烯、癸醛、苯甲醛和苯乙醛的量显著增加。我们还发现，在大多数采样场合，在有甲虫存在的石南花和没有甲虫存在的石南花植物中产生的挥发物存在显著差异。我们还记录到，在有 的地方，石南花上的一般性食草动物数量较少。讨论了入侵植物、新环境以及它们入侵的本地社区之间的相互作用。
