Varietal Differences in Cell Wall -(13)C(14)-Glucan and Nonstructural Carbohydrate in Rice Stems during the Grain Filling Stage
Arai-Sanoh,Y., Ida,M., Zhao,R., Nishitani,K., Yoshinaga,S., Takai,T., Nakano,H., Iwasawa,N., Kondo, M.
Plant Prod. Sci. 16:335-341
The contribution of cell wall components and nonstructural carbohydrate (NSC) to grain filling in rice (Oryza sativa L.) was clarified by investigating the differences in the dynamics of
hemicellulose, sugar composition of hemicellulose, -(13),(14)-glucan, and NSC among cultivars with different grain fi lling capacities. This investigation was performed using the stems of standard, high yield and low harvest index (HI) cultivars. Hemicellulose concentration in stems tended to decrease slightly during the grain fi lling stage. This decrease was attributed to a decrease in -(13),(14)-glucan concentration, which was detected as a decrease in glucose composition of hemicellulose in the stems during the grain fi lling stage. The rate of decrease and decrease in the amount of -(13),(14)-glucan in the stems differed among the cultivars. These were higher in high yield and high HI cultivars than in relatively low yield and low HI cultivars. Moreover, a positive
correlation was observed between the rate of decrease in (13),(14)-glucan and NSC, indicating similarities in the dynamics of -(13),(14)-glucan and NSC among the cultivars. When the top half of panicle was removed, -(13),(14)-glucan and NSC concentrations in the culm and leaf sheath did not decrease during the grain fi lling stage. Therefore, the -(13),(14)-glucan in stems might be one of the sources that supply substrate to panicle as well as NSC.