Abstract:
Although the use of airborne molecules as infochemicals is common in terrestrial plants, it has not been shown to occur in an ecologically relevant context in marine seaweeds. Like terrestrial plants, intertidal plants spend part of their lives emersed at low tide and release volatile organic compounds (VOCs) into the air when they are grazed or physiologically stressed. We hypothesized seaweeds could use airborne VOCs as infochemicals and respond to them by upregulating a keystone defensive metabolite, dimethylsulfoniopropionate (DMSP). We conducted laboratory and field experiments in which Ulva fenestrata was exposed to airborne dimethyl sulfide (DMS), a volatile antiherbivore and antioxidant metabolite released when the seaweed is grazed or physiologically stressed. In the laboratory, U. fenestrata exposed to DMS had 43-48% higher DMSP concentrations, relative to controls, 6-9 days after exposure. In the field, U. fenestrata 1 m downwind of DMS emitters had 19% higher DMSP concentrations than upwind seaweeds after 11 days. To our knowledge, this is the first demonstration of a marine plant using an airborne molecule released when damaged to elicit defensive responses. Our study suggests that the ability to detect airborne compounds has evolved multiple times or before the divergence of terrestrial plants and green algae.
摘要:
尽管在陆地植物中使用空气传播分子作为信息化学物质很常见,它没有被证明发生在海洋海藻的生态相关的背景下。像陆生植物一样,潮间带植物的一部分生命是在低潮时出现的,当它们被放牧或受到生理压力时,会将挥发性有机化合物(VOC)释放到空气中。我们假设海藻可以使用空气中的挥发性有机化合物作为信息化学物质,并通过上调基石防御代谢物来对它们做出反应,二甲基磺丙酸酯(DMSP)。我们进行了实验室和现场实验,其中Ulvafenestrata暴露于空气中的二甲基硫醚(DMS),当海藻被放牧或生理应激时释放的挥发性抗草食动物和抗氧化剂代谢产物。在实验室里,暴露于DMS的U.fenestrata的DMSP浓度高43-48%,相对于控件,暴露后6-9天。在田野里,11天后,顺风1m的DMS发射器的DMSP浓度比逆风海藻高19%。据我们所知,这是海洋植物利用受损时释放的空气分子引发防御性反应的首次演示。我们的研究表明,检测空气传播化合物的能力已经进化了多次或在陆生植物和绿藻分歧之前。