Changes in Carbohydrate Content and the Activities of Acid Invertase, Sucrose Synthase and Sucrose Phosphate Synthase in Vegetable Soybean During Fruit Development

摘要

This study investigated the changes in carbohydrate content and activities of acid invertase, sucrose synthase (SS) and sucrose phosphate synthase (SPS) in two vegetable soybean cultivars (Glycine max (L.) Merr. vars. Ajigen and Fuuki) during fruit development ranging from 28 to 63 days after anthesis. In both cultivars, sucrose was the predominant sugar while fructose and glucose were found in trace amounts. Sucrose accumulation was highest at 35 and 42 days after anthesis in Fuuki and Ajigen, respectively. On the other hand, fructose and glucose were almost maintained throughout the experimental period. The activity of soluble acid invertase was highest at the 42 days but was not maintained until the 63 days after anthesis. The acid invertase activity in cell wall-bound fraction was highest in young fruit (28 days after anthesis) and gradually decreased throughout development. Ajigen had higher activity than Fuuki. SS activity showed a continuous increase with time while SPS activity did not showspecific inclining or declining pattern. SS and SPS activities in Fuuki were higher than Ajigen. There was a highly significant negative correlation observed between the acid invertase activity in cell wall-bound fraction and sucrose content in Ajigen.A significant positive correlation was also found between the SS and SPS activities and sucrose content in Fuuki. However, a highly significant negative correlation was observed between SS activity and other soluble sugars (glucose and fructose) in bothcultivars except glucose content in Fuuki. No significant correlation was found between the SPS activity and other soluble sugars (glucose and fructose) in both cultivars.