Біологічні студії (Jul 2022)
Dynamics of foliar concentrations of photosynthetic pigments in woody and herbaceous plant species in the territory of an industrial city
Abstract
Background. Plants growing in urban ecosystems are negatively affected by anthropogenic activities associated with environmental pollution. Plant photosynthesis is one of the processes that are particularly affected by environmental conditions, including the presence of pollutants in the atmosphere and soil. However, the dynamics of photosynthetic pigments, namely chlorophylls (Chl) and carotenoids, in plant species growing in urban ecosystems have not been sufficiently studied. The aim of this study was to analyze the effect of technogenic load on the content of pigments of photosynthesis in the cells of woody and herbaceous plants common in industrial cities, using the example of the urban ecosystem of Lviv located in the western part of Ukraine. Materials and Methods. The study was carried out at four experimental sites within the city of Lviv with different levels and types of technogenic load. Site S1 selected in the central part of the Stryiskyi park was considered as a control one. Site S2 was chosen in an area with a combined technogenic load, including road and rail traffic, and the operation of the combined heat and power plant-1 (CHPP-1). Sites S3 and S4 were subjected mainly to vehicular traffic. Leaves of six plant species were collected at sites S1–S4, including woody plants (Acer platanoides L., Aesculus hippocastanum L. and Tilia cordata Mill.) and herbaceous plants (Plantago major L., Taraxacum officinale F.H.Wigg. and Urtica dioica L). The concentration of Chl a, Chl b, the total Chl content and the concentration of carotenoids were determined spectrophotometrically. Results. The analyzed plant species growing at site S1 had the highest levels of total Chl and carotenoids compared to other sampling sites. In plant leaves collected at sites S2–S4, the total Chl content was 1.5–3.2 times lower than in the leaves collected at the site S1. The ratio of Chl a and Chl b concentrations was generally lower in plants growing at sites S2–S4 compared to plants from site S1. The concentration of carotenoids in the leaves of woody plants collected from sites S2 and S4 was 1.4–2.4 times lower compared with site S1, while in the leaves of herbaceous plants sampled at sites S2–S4, the concentration of carotenoids was 1.5–2.6 times lower than at site S1. Conclusions. The results of the study suggest that the concentration of both chlorophyll and carotenoids in the leaves of the analyzed herbaceous and woody plant species growing in the territory of an industrial city is influenced by anthropogenic impact associated with atmospheric pollution in the areas of plant growth. These indices are lower in plants growing in areas with technogenic load compared with plants growing in the green zone of the city. At the same time, the concentration of chlorophyll in the leaves of the analyzed plant species growing under urban conditions was found to be more sensitive to anthropogenic load compared to the foliar concentration of carotenoids. Therefore, the concentration of chlorophyll in plant species growing in cities can be one of the biomarkers for assessing the level of pollution caused by anthropogenic load in urban ecosystems.
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