Abstract: In order to explore the dynamic effects on sugar metabolism of soybean seeds under acid rain stress,in this experiment soybean seeds were leached by distilled water and then treated with simulated acid rain(pH2.5 and pH4.5). The effect of acid rain stress strength on the contents of soluble sugar,reducing sugar,sucrose,starch and α,β-amylase activity of soybean seeds were studied in this paper. The results showed that the content of soluble sugar of AR group rose sharply on the first day and declined significantly on the second day and decreased slowly from then on. The content of reducing sugar of AR group was high in the first 4 days,but declined from the 3rd to 5th day. The content of sucrose of pH2.5 group decreased from the 2nd to 5th day. The content of starch of AR group declined from the 2nd to 4th day. The α-amylase activity of pH4.5 group was higher than CK,but that target of pH2.5 group was lower than CK after the 4th day. The β-amylase activity was higher or equal to CK from the 1st to 6th day,pH2.5 group was lower than CK on the 7th day. All targets of sugar metabolism and amylase activity indicated that the contents of soluble sugar,reducing sugar and sucrose increased with increasing acid rain stress strength,however,the starch was contrary. The effect of acid rain on amylase activity was one of the reasons of germination change.

Key words: Acid rain, Acid rain, Soybean, Seed germination, Sugar metabolism