Ryan A, Cojocariu C, Possell M, Davies W J, Hewitt C N
Lancaster Environment Centre, Lancaster University, Lancaster, UK.
Plant Cell Environ. 2009 Jan;32(1):31-45. doi: 10.1111/j.1365-3040.2008.01897.x.
This study examined whether two genotypes of hybrid poplar (Populus deltoides x Populus trichocarpa), previously classified as ozone tolerant and ozone sensitive, had differing physiological and biochemical responses when fumigated with 120 nL L(-1) ozone for 6 h per day for eight consecutive days. Isoprene emission rate, ozone uptake and a number of physiological and biochemical parameters were investigated before, during and after fumigation with ozone. Previous studies have shown that isoprene protects plants against oxidative stress. Therefore, it was hypothesized that these two genotypes would differ in either their basal isoprene emission rates or in the response of isoprene to fumigation by ozone. Our results showed that the basal emission rates of isoprene, physiological responses and ozone uptake rates were all similar. However, significant differences were found in visible damage, carotenoids, hydrogen peroxide (H(2)O(2)), thiobarbituric acid reactions (TBARS) and post-fumigation isoprene emission rates. It is shown that, although the classification of ozone tolerance or sensitivity had been previously clearly and carefully defined using one particular set of parameters, assessment of other key variables does not necessarily lead to the same conclusions. Thus, it may be necessary to reconsider the way in which plants are classified as ozone tolerant or sensitive.
本研究考察了两种杂交杨树（三角叶杨×毛果杨）的基因型，这两种基因型之前被分类为耐臭氧型和臭氧敏感型，当连续八天每天用120 nL L⁻¹的臭氧熏蒸6小时时，它们是否具有不同的生理和生化反应。在臭氧熏蒸之前、期间和之后，研究了异戊二烯排放率、臭氧吸收率以及一些生理和生化参数。先前的研究表明，异戊二烯可保护植物免受氧化应激。因此，我们假设这两种基因型在基础异戊二烯排放率或异戊二烯对臭氧熏蒸的反应方面会有所不同。我们的结果表明，异戊二烯的基础排放率、生理反应和臭氧吸收率均相似。然而，在可见损伤、类胡萝卜素、过氧化氢（H₂O₂）、硫代巴比妥酸反应（TBARS）以及熏蒸后的异戊二烯排放率方面发现了显著差异。结果表明，尽管先前使用一组特定参数已经明确且仔细地定义了耐臭氧或敏感的分类，但对其他关键变量的评估不一定会得出相同的结论。因此，可能有必要重新考虑将植物分类为耐臭氧或敏感型的方式。
