Changes of metabolism of rice plant under fiooding (Preliminary report)

Abstract

When rice plant was submerged under water, sugars such as reducing sugar and sucrose were used up rapidly, while acid-hydrolysable polysaccharides including starch and hemicellulose were also decreased to some extent. Protein hydrolysis was observed to be inhibited by the deficiency of oxygen. Soluble nitrogenous fraction increased soon after flooding, reaching to a peak, and then decreased. All these changes suggest that available substrate of respiration was exhausted under water. This idea was supported by the fact that CO₂ output of tissue under water was decreased to about one-thirds of that of control plant after three days of flooding. That the plant, when supplied with light, are able to carry on photosynthesis even under water was shown.