Individual and combined effects of fluoranthene, phenanthrene, mannitol and sulfuric acid on marigold (Calendula officinalis)

Wahdatullah Khpalwak; Sherif M Abdel-Dayem; Hiroshi Sakugawa

doi:10.1016/j.ecoenv.2017.11.065

Individual and combined effects of fluoranthene, phenanthrene, mannitol and sulfuric acid on marigold (Calendula officinalis)

Ecotoxicol Environ Saf. 2018 Feb:148:834-841. doi: 10.1016/j.ecoenv.2017.11.065. Epub 2017 Dec 1.

Authors

Wahdatullah Khpalwak¹, Sherif M Abdel-Dayem², Hiroshi Sakugawa³

Affiliations

¹ Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima 739-8521, Japan; Department of Plant Protection, Faculty of Agriculture, Nangarhar University, Nangarhar, Afghanistan.
² Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima 739-8521, Japan; Department of Pesticide Chemistry, Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, Egypt.
³ Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima 739-8521, Japan. Electronic address: hsakuga@hiroshima-u.ac.jp.

PMID: 29197798
DOI: 10.1016/j.ecoenv.2017.11.065

Abstract

A study was conducted to characterize marigold stress response to polycyclic aromatic hydrocarbons (PAHs) (oxidative stress inducers) with and without sulfuric acid (S.Acid; pH 3) (acid-stress inducer), and to evaluate reactive oxygen species (ROS) scavenging activity of mannitol (Mann). Marigold (Calendula officinalis) seedlings were grown in a greenhouse and fumigated with fluoranthene (FLU), phenanthrene (PHE), Mann, and S.Acid individually and in various combinations for 40 days. Various physiological and biochemical parameters among others were analyzed using standard methods. The results revealed that fumigation of FLU induced oxidative stress to the plants via ROS generation leading to negative effects on photosynthesis at near saturating irradiance (A_max), stomatal conductance (G_s), internal carbon dioxide concentration (C_i), leaf water relations and chlorophyll pigments. Significant per cent inhibition of A_max (54%), G_s (86%) and C_i (32%), as well as per cent reductions in chlorophyll a (Chl.a) (33%), Chl.b (34%), and total chlorophyll (Tot. Chl) (48%) contents were recorded in FLU fumigated treatment in comparison to control. Combination of Mann with FLU scavenged the generated ROS and substantially lowered the oxidative stress on the plants hence all the measured parameters were not significantly different from control. PHE fumigation had varied effects on marigold plants and was not as deleterious as FLU. Combined fumigation of S.Acid with both the PAHs had significant negative effect on leaf water relations, and positive effect on fresh and turgid weight of the plants but had no effect on the other measured parameters. The lowest proline contents and highest catalase and ascorbate peroxidase activities in FLU fumigated plants further confirmed that oxidative stress was imposed via the generation of ROS. From the results, it is evident that Mann could be an efficient scavenger of ROS-generated by FLU in the marigold plants. We recommend Mann to be widely used for the protection of higher plants from FLU-generated stress in the urban areas.

Keywords: Antioxidant enzyme activities; Fluoranthene; Marigold; Oxidative stress; Reactive oxygen species.

MeSH terms

Calendula / drug effects*
Calendula / growth & development
Calendula / metabolism
Chlorophyll / metabolism
Drug Synergism
Fluorenes / toxicity
Fumigation*
Mannitol / toxicity
Oxidative Stress / drug effects*
Phenanthrenes / toxicity
Photosynthesis / drug effects*
Polycyclic Aromatic Hydrocarbons / toxicity*
Reactive Oxygen Species / metabolism
Sulfuric Acids / toxicity

Substances

Fluorenes
Phenanthrenes
Polycyclic Aromatic Hydrocarbons
Reactive Oxygen Species
Sulfuric Acids
Chlorophyll
fluoranthene
Mannitol
phenanthrene
sulfuric acid