Abstract

THE EFFECT OF GASEOUS AIR POLLUTANTS AND ASCORBIC ACID ON CARBOHYDRATE CONTENT OF BEANS (PHASEOLUS VULGARIS L.)PLANT IN RIYADH CITY, KINGDOM OF SAUDI ARABIA

Mohammed Abdul Rahman Al-Muwayhi

Abstract

This study was conducted at three locations varying pollution ozone, sulfur dioxide and nitrogen dioxide gases in Riyadh city. The seeds of beans (Phaseolus vulgaris L.) were planted in the greenhouse belonging to Department of Botany and Microbiology, Faculty of Science, King Saud University, where it was put three pots for each concentration of ascorbic acid (zero, 50,200,400 mg/L) each of which three seeds of beans, The seeds were cultivated on 20 May 2011, and left until the completion of the growth of primary leaves, then transferred to the study sites, i.e. King Saud University, the first industrial city, and the cement factory. The results showed that the concentration of gases contaminated air in the city of Riyadh was gradually increased during the study period, reaching concentration of ozone gas to 87 (ppb) at the cement factory site, sulfur dioxide gas to 27 (ppb) at the site of the first industrial city and the nitrogen dioxide gas to 26 (ppb) in a cement factory. Also, the results showed that there was a significant effect of those pollutants on carbohydrate content, where the content of monosaccharide’s in beans leaves was ranging between 8.8 to 6.2 (mg/g) at the King Saud University and the cement factory sites, respectively. The disaccharides content was ranging between 24.7 to 21.1(mg/g) at University of King Saud and cement factory sites, respectively. The polysaccharides content was ranging between 39.3 (mg/g) at King Saud University and 34.2 (mg/g) in a factory cement sites, respectively. The study also proved that ascorbic acid (ASA) had a positive role on the metabolism of carbohydrates and plant resistance to oxidizer ozone gas, which supports the proposed role of ascorbic acid in the removal of toxic oxygen species, in addition to its ability to resist environmental stress factors.

Keywords: Air pollutants, Ascorbic acid (ASA), Beans plant and Carbohydrates content.