Chauhan Aprajita
School of Environmental Sciences, Jawaharlal Nehru University, 110 067, New Delhi, India.
Oecologia. 1990 Oct;84(3):289-294. doi: 10.1007/BF00329752.
Fumigation experiments with SO performed on the seedlings of three plant species viz, tomato (Lycopersicon esculentum), mung bean (Vigna radiata) and maize (Zea mays) resulted in the emission of volatiles. Acetaldehyde and ethanol were produced in the fumigated plants. In addition, there was also an increased production of ethylene and ethane. The production of these volatiles was positively correlated to the SO concentrations of 4.2 and 8.3 μmol m (0.1 and 0.2 ppm). Ethylene was emitted primarily from SO-stressed yet healthy leaves, whereas high ethane levels were detected in leaves with visible injury symptoms. However, with the appearance of visible injury symptoms, there was a decline in ethylene, acetaldehyde and ethanol emissions. Synthesis of ethylene and ethane seems to be a result of different metabolic pathways. Ethane evolution and its inhibition by antioxidants indicate SO-mediated lipid peroxidation by free radical species formed during sulphite oxidation. Perturbation in the cellular respiratory machinery results in the formation of acetaldehyde and ethanol. Since the rates of emissions of ethane, acetaldehyde and ethanol fromplant species were positively correlated to their relative resistance to SO, the production of these gases could be used as a reliable diagnostic tool for biomonitoring air pollution (SO) stress.
对三种植物幼苗，即番茄（Lycopersicon esculentum）、绿豆（Vigna radiata）和玉米（Zea mays）进行的二氧化硫熏蒸实验导致了挥发性物质的释放。熏蒸过的植物产生了乙醛和乙醇。此外，乙烯和乙烷的产量也有所增加。这些挥发性物质的产生与4.2和8.3 μmol m（0.1和0.2 ppm）的二氧化硫浓度呈正相关。乙烯主要从受到二氧化硫胁迫但仍健康的叶片中释放，而在出现可见损伤症状的叶片中检测到高浓度的乙烷。然而，随着可见损伤症状的出现，乙烯、乙醛和乙醇的释放量有所下降。乙烯和乙烷的合成似乎是不同代谢途径的结果。乙烷的释放及其被抗氧化剂抑制表明，二氧化硫通过亚硫酸盐氧化过程中形成的自由基物种介导脂质过氧化。细胞呼吸机制的紊乱导致乙醛和乙醇的形成。由于植物物种中乙烷、乙醛和乙醇的释放速率与它们对二氧化硫的相对抗性呈正相关，这些气体的产生可以用作生物监测空气污染（二氧化硫）胁迫的可靠诊断工具。
