Ferreira Maurício Lamano, Nobre Esposito Jéssica Bordotti, de Souza Silvia Ribeiro, Domingos Marisa
Universidade Nove de Julho, Faculdade de Biologia, São Paulo, SP, Brazil.
J Environ Monit. 2012 Jul;14(7):1959-67. doi: 10.1039/c2em30026e. Epub 2012 Jun 18.
This study aimed to analyze critically the potential of Ipomoea nil'Scarlet O'Hara' for O(3) biomonitoring in the sub-tropics. Four field experiments (one in each season of 2006) were carried out in a location of the city of São Paulo mainly polluted by O(3). Each experiment started with 50 plants, and lasted 28 days. Sub-lots of five plants were taken at intervals between three or four days long. Groups of four plants were also exposed in closed chambers to filtered air or to 40, 50 or 80 ppb of O(3) for three consecutive hours a day for six days. The percentage of leaf injury (interveinal chloroses and necroses), the concentrations of ascorbic acid (AA) and the activity of superoxide dismutase (SOD) and peroxidases (POD) were determined in the 5th, 6th and 7th oldest leaves on the main stem of the plants taken in all experiments. Visible injury occurred in the plants from all experiments. Seasonality in the antioxidant responses observed in plants grown under field conditions was associated with meteorological variables and ozone concentrations five days before leaf analyses. The highest levels of antioxidants occurred during the spring. The percentage of leaf injury was explained (R(2) = 0.97, p < 0.01) by the reduction in the levels of AA and activity of POD five days before the leaf analyses and by the reduction in the levels of particulate matter, and enhancement of temperature and global radiation 10 days before this same day. Although I. nil may be employed for qualitative O(3) biomonitoring, its efficiency for quantitative biomonitoring in the sub-tropics may be compromised, depending on how intense the oxidative power of the environment is.
本研究旨在批判性地分析矮牵牛‘猩红奥哈拉’在亚热带地区进行O₃生物监测的潜力。2006年的四个季节，在圣保罗市一个主要受O₃污染的地点进行了四项田间试验。每项试验开始时有50株植物，持续28天。每隔三或四天取五株植物的子样本。另外，将四株植物的组放置在封闭的试验箱中，每天连续三小时暴露于过滤空气或40、50或80 ppb的O₃中，持续六天。测定所有试验中所取植物主茎上第5、6和7片最老叶子的叶损伤百分比（脉间黄化和坏死）、抗坏血酸（AA）浓度以及超氧化物歧化酶（SOD）和过氧化物酶（POD）的活性。所有试验中的植物都出现了可见损伤。在田间条件下生长的植物中观察到的抗氧化反应的季节性与叶片分析前五天的气象变量和臭氧浓度有关。抗氧化剂的最高水平出现在春季。叶损伤百分比可由叶片分析前五天AA水平的降低、POD活性的降低以及颗粒物水平的降低，以及同一天前十天温度和总辐射的增加来解释（R² = 0.97，p < 0.01）。尽管矮牵牛可用于定性O₃生物监测，但其在亚热带地区进行定量生物监测的效率可能会受到影响，这取决于环境氧化能力的强弱。
