Uptake and Metabolism of NaH<SUP>35</SUP>SO<SUB>3</SUB> in Rice and Barley Seedlings

Abstract

Comparative laboratory experiments regarding the effects of NaHSO3 on growth and the incorporation of NaH35SO3 into rice and barley seedlings were examined.Both rice and barley seedlings showed much lower growth above 10-3M(=mol/1) concentration of NaHSO3 in the medium, than the control. The reduced ratio to the control was higher in barley than in rice.Total incorporation of NaH35SO3 declined with an increase of NaHSO3 during culture. Rice incorporated NaH35SO3 into the tissues much more than barley at late phase of culture and pooled it as an inorganic form without translocation to organic metabolites. However in barley, the fixation of NaH35SO3 in the ethanol insoluble and cationic fraction increased remarkably during culture. In the two plant tissues at 10-3 M, the 35S distribution into sulfur amino acids in the cationic fraction was lower than that of control. More than 80% of the radioactivity was occupied by sulfur amino acids in the protein hydrolysates similarly in rice and barley.