The Characteristics Of Sulfur Metabolism In Soybean (Glycine.max (L.) Merrill)

This research was conducted in the experiment unit of Northeast Agricultural University from 2004 to 2005. Three cultivals, DongNong42, DongNong46 and HeFeng25 were tested by means of pots and fields experiments with four sulfur application levels (0, 9, 18, 27 kg/hm2 ) to study the effect of sulfur on photnsynthesis, S-metabolism, roots activity, sulfur accumulation and distribution, yield and quality of soybean. The result showed that:The dynamics of RuBPCase activity was similar to that of the soluble sugar contents among different genotypes. The strongest activity of RuBPCase was at poding stage. Sulfur application exhibited much different effects on the indexes of photosynthesis of various genotypes. It increased the activity of RuBPCase and thus promoted the photosynthesis of HeFeng25 and DongNong46, but it excised an adverse effect on the activity of RuBPCase of DongNong 42. The contents of soluble sugar in the leaves were not influenced significantly, while that in the stems, pods and seeds were influenced appreciably. Sulfur application increased the contents of soluble sugar in the seeds of DongNong42 and HeFeng 25, but did the reverse in DongNong46.Sulphur application influenced the activities of ATP-sulfureylase and O-acetylserine sulfhydrylase and the contents of glutathione differently at every stage and among different genotypes. At florencence, ATP-sulfureylase activities of HeFeng25 were increased heavily, while that of DongNong46 and DongNong42 were decreased. At podding stage, ATP-sulfureylase activities of the three tested varieties reached the highest, and at this time the effect of sulphur was positive, i.e., increased the activities of ATP-sulfureylase.The highest activity of O-acetylserine sulfhydrylase occurred at fulling stage. Except for that of HeFeng25 at V4 was decreased when applied with sulphur, the activites of O-acetylserine sulfhydrylase at others stages were increased. In the case of DongNong42 and DongNong46, it was decreased from V4 to R2, and thereafter was increased. Effects of sulphur application on the content of glutathione were opposite to that of DongNong42 and DongNong46.Roots activity and the contents of soluble protein in roots were influenced by sulfur application. High sulfur application could supressed the activity of roots. Applying sulfur could make DongNong 46 keep high roots activity all along time, and kept higher with light sulfur application. The correlationship between the roots activity and contents of soluble peotein in roots was not significant.In each organ, sulfur content was affected significantly by different external sulfur concentrations. In generally, it increased in the treatments with sulfur application. Most of suphur was absorbed after flowering. Applying Sulfur increased the accumulation of sulfur in...