Impact of O3, SO2 and NO2 on Carbohydrate Content Level in Bean Plant (Phaseolus vulgaris L.) Grown Under Ascorbic Acid at Various Sites of Riyadh, Kingdom of Saudi Arabia

Abstract

This study was conducted at three locations of Riyadh under varying pollution of ozone, sulfur dioxide and nitrogen dioxide gases. The bean seeds were grown in three pots under concentrations of ascorbic acid (zero, 100, 200, 300 mg/L). The results showed that the concentration of polluted air in the Riyadh was gradually increased during the study period, reaching concentration of ozone gas to 77 (ppb) at the urban area site, sulfur dioxide gas to 21 (ppb) at the site of the sub-urban area and the nitrogen dioxide gas to 22 (ppb) in a urban area. The results also showed that there was a significant effect of those pollutants on carbohydrate content, where the content of monosaccharides in beans leaves were ranging between 8.1 to 5.7 (mg/g) at the rural area and the urban area sites, respectively. The disaccharides content was ranging between 23.0 to 20.6 (mg/g) at rural area and urban area sites, respectively. The polysaccharides content was ranged between 38.8 (mg/g) at rural area and 33.7 (mg/g) in an urban area sites, respectively. The study also proved that ascorbic acid (ASA) had a positive role on the metabolism of carbohydrates and provides plant resistance to oxidizer ozone gas, which supports the proposed role of ascorbic acid in the removal of toxic free radical species, in addition to its ability to resist environmental stress factors. © 2011 IGJPS. All rights reserved.