State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
Plant Cell Environ. 2017 Sep;40(9):1960-1971. doi: 10.1111/pce.13007. Epub 2017 Jul 14.
Concentration- and flux-based O dose-responses of isoprene emission from single leaves and whole plants were developed. Two poplar clones differing in O sensitivity were exposed to five O levels in open-top chambers for 97 d: charcoal-filtered ambient air (CF), non-filtered ambient air (NF) and NF plus 20 ppb (NF + 20), 40 ppb (NF + 40) and 60 ppb (NF + 60). At both leaf and plant level, isoprene emission was significantly decreased by NF + 40 and NF + 60 for both clones. Although intra-specific variability was found when the emissions were up-scaled to the whole plant, both leaf- and plant-level emissions decreased linearly with increasing concentration-based (AOT40, cumulative exposure to hourly O concentrations >40 ppb) and flux-based indices (POD , cumulative stomatal uptake of O > Y nmol O m PLA s ). AOT40- and POD -based dose-responses performed equally well. The two clones responded differently to AOT40 and similarly to POD (with a slightly higher R for POD ) when the emission was expressed as change relative to clean air. We thus recommend POD as a large-scale risk assessment metric to estimate isoprene emission responses to O in poplar.
建立了基于浓度和通量的异戊二烯排放的 O 剂量响应，分别来自单叶和整株植物。两个对 O 敏感程度不同的杨树无性系在开放顶室中暴露于五种 O 水平下 97 天：活性炭过滤的环境空气（CF）、未过滤的环境空气（NF）和 NF 加 20 ppb（NF+20）、40 ppb（NF+40）和 60 ppb（NF+60）。在叶片和植株水平上，NF+40 和 NF+60 均显著降低了两个无性系的异戊二烯排放。尽管在将排放物放大到整个植株时发现了种内变异性，但叶片和植株水平的排放均随浓度（AOT40，每小时 O 浓度>40 ppb 的累积暴露）和通量（POD，O 的累积气孔吸收量>Y nmol O m PLA s）的增加呈线性下降。AOT40 和 POD 基剂量响应表现相当。当排放以相对于清洁空气的变化表示时，两个无性系对 AOT40 的反应不同，但对 POD 的反应相似（POD 的 R 值略高）。因此，我们建议使用 POD 作为一种大规模风险评估指标，以估计杨树中 O 对异戊二烯排放的响应。
