Impact of gaseous air pollutants on lipid and protein content of beans (Phaseolus vulgaris L.) plant growing at urban, sub‐urban, and rural sites of the Riyadh, Kingdom of Saudi Arabia

Abstract

The current study was conducted at three locations varying in pollution with ozone, sulfur dioxide and nitrogen dioxide in the Riyadh, Kingdom of Saudi Arabia. Phaseouls vulgaris was sown in the pots and irrigated with different concentrations of ascorbic acid solution and it was grown in polluted areas. The results showed that the concentrations of polluting gases in the air in the Riyadh increased during the study period, reaching the concentration of ozone gas to 77 ppb in urban area, and sulfur dioxide to 21 ppb in the suburban area, and nitrogen dioxide to 22 ppb in the urban area. There was a significant effect of those pollutants on the protein and fat content of the test plant, where the content of protein in the leaves was 4.09% at the rural area, 3.87% in the suburban area and 3.81% at the urban area. At the same time the lipid content of the leaves was 2.7% at rural area, 2.9% in the sub‐urban area and 2.3% in the urban area. The treatment of ascorbic acid increased the level of protein and lipid contents of these plants. Protein content in the leaves was 4.73% at rural area, 4 % in the sub‐urban area and 3.97% in the urban area. The lipid content of the leaves was 3 % at rural area, 2.7% in the sub‐urban area and 2.6% at the urban area. This study proved the role of ascorbic acid (ASA) in the plant as it increased the resistance against the ozone gas oxidizer, and thereby helping in the removal of toxic reactive oxygen species.