Abstract：
Isoprenoids (including isoprene (ISO) and monoterpenes (MTs)) are the majority of biogenic volatile organic compounds (BVOCs) which are important carbon-containing secondary metabolites biosynthesized by organisms, especially plant in terrestrial ecosystem. Results of the warming effects on isoprenoid emissions vary within species and warming facilities, and thus conclusions remain controversial. In this study, two typical subtropical tree species seedlings of Schima superba and Cunninghamia lanceolata were cultivated under three conditions, namely no warming (CK) and two warming facilities (with infrared radiators (IR) and heating wires (HW)) in open top chamber (OTC), and the isoprenoid emissions were measured with preconcentor-GC-MS system after warming for one, two and four months. The results showed that the isoprenoid emissions from S. superba and C. lanceolata exhibited uniformity in response to two warming facilities. IR and HW both stimulated isoprenoid emissions in two plants after one month of treatment, with increased ratios of 16.3 % and 72.5 % for S. superba, and 2.47 and 5.96 times for C. lanceolata. However, the emissions were suppressed after four months, with more pronounced effect for HW. The variation in isoprenoid emissions was primarily associated with the levels of Pn, Tr, monoterpene synthase (MTPS) activity. C. lanceolata predominantly released MTs (mainly α-pinene, α-terpene, γ-terpene, and limonene), with 39.7 % to 99.6 % of the total isoprenoid but ISO was only a very minor constituent. For S. superba, MTs constituted 24.7 % to 96.1 % of total isoprenoid. It is noteworthy that HW generated a greater disturbance to physiology activity in plants. Our study provided more comprehensive and more convincing support for integrating temperature-elevation experiments of different ecosystems and assessing response and adaptation of forest carbon cycle to global warming.
摘要：
类异戊二烯（包括异戊二烯（ISO）和单萜（MTs））是大多数生物挥发性有机化合物（BVOCs），是生物体生物合成的重要含碳次级代谢产物。尤其是陆地生态系统中的植物。变暖对类异戊二烯排放的影响结果因物种和变暖设施而异，因此结论仍然存在争议。在这项研究中,在三种条件下培育了两种典型的亚热带树种苗木和杉木，即无加热（CK）和两个加热设施（带有红外辐射器（IR）和加热线（HW））在开顶室（OTC）中，加温后，用preconcentor-GC-MS系统测量类异戊二烯的排放量，两个月和四个月。结果表明，S.superba和C.lanceolata的类异戊二烯排放在响应两个变暖设施时表现出均匀性。处理一个月后，IR和HW都刺激了两种植物的类异戊二烯排放，S.superba的比率分别增加了16.3%和72.5%，杉木的2.47和5.96倍。然而,四个月后排放得到抑制，对HW有更明显的影响。类异戊二烯排放的变化主要与Pn的水平有关，Tr,单萜合酶(MTPS)活性。C.杉木主要释放MTs(主要是α-pine烯，α-萜烯,γ-萜烯,和柠檬烯)，占总的类异戊二烯的39.7%至99.6%，但ISO仅是非常次要的成分。对于S.Superba来说，MTs占总类异戊二烯的24.7%至96.1%。值得注意的是，HW对植物的生理活动产生了更大的干扰。我们的研究为整合不同生态系统的温度升高实验以及评估森林碳循环对全球变暖的响应和适应提供了更全面，更令人信服的支持。
