Interactive effects of simultaneous ozone and fluoranthene fumigation on the eco-physiological status of the evergreen conifer, Japanese red pine (Pinus densiflora Sieb et. Zucc.)

Abstract

Forest decline has long been attributed to air pollution and acid rain/fog, with ozone having a record for damaging trees. This study investigated eco-physiological changes on Japanese red pine caused by simultaneous fumigation of O(3) (O) and fluoranthene (F) over a 90 day period. Seedlings were exposed individually or in combinations to 10 muM fluoranthene and O(3) (3 ppm and 6 ppm in 60 days and 90 days, respectively) inside growth chambers. Eco-physiological parameters monitored included gas exchange, chlorophyll fluorescence, needle chlorophyll content, and visual appearance. After 90 days, O + F treatment showed deleterious effects on visual needle appearance and the net photosynthesis rate near saturated irradiance. In addition, decreased levels in stomatal conductance, photochemical efficiency of PS II in the dark, and total chlorophyll and Chl a: Chl b were observed. F only treatment showed similar results but in lesser magnitude compared with F + O treatment. O treatment alone showed no significant negative effect, probably due to its low concentration in the 60 day treatment. The addition of mannitol (OH radical scavenger) mitigated O + F and F negative effects. Fluoranthene deposited on Japanese red pine presents great eco-physiological damage risk, even at low O(3) concentration. Furthermore, the effects of O(3) assisted phyto-toxicity of fluoranthene on red pine may have relevance to other plant species.

Distribution and sources of particulate polycyclic aromatic hydrocarbons (PAHs) in air of Kamihaya, central Japan

“…For example, low concentrations (10 mM) of Flt created adverse effects on red pine seedlings such as decreased needle gas exchange, chlorophyll content, photosynthesis, and foliar damage (Oguntimehin et al, 2008). However, combination of Flt with other pollutants such as ozone (120 ppb) and pH 3 acid mist aggravated these effects (Oguntimehin and Sakugawa, 2009;Qguntimehin et al, 2013). The amount of Flt applied to each pine seedling in their experiments was equivalent to a deposition rate of 116 mg m -3 d -1 on pine needles, which is about 40 times higher than the deposition rate of ambient level Flt (ca.…”

“…Even if the concentration of individual PAH in the atmosphere is low, they have the potential to cause increased phytotoxicity when present in combination with total PAHs and/or other chemicals (Oguntimehin et al, 2010a, b). For example, ozone was found to have an adverse effect on Japanese pine (Oguntimehin and Sakugawa, 2009) and cherry tomato (Oguntimehin et al, 2010b) in a chamber experiment in which it was administered at 120 ppb in combination with 10 mM fluoranthene (Flt) for 34 days, suggesting that Flt exacerbates the negative effects of ozone. Similarly, increased phytotoxicity was reported in response to the application of Flt in conjugation with acid mist (Oguntimehin et al, 2013).…”

Investigating role of Triton X-100 in ameliorating deleterious effects of anthracene in wheat plants

“…Images from transmission electron microscopy have revealed that PAHs can cause gross deformation in chloroplasts and may lead to oxidation stress (Liu et al 2009). PAHs have been found to enhance production of reactive oxygen species (ROS) in higher plants (Oguntimehin and Sakugawa 2009). Several studies have shown inhibitory effects of PAHs on donor and acceptor sides of PSII including oxygen evolving complex (OEC) and electron transport chain (Aksmann andTukaj 2008, Kummerova et al 2006).…”