Studies on the Relation between the Tolerance of Crops to Soil Acidity and that to low pH : (12) The character of Fraction I and Fraction II of cytoplasmic protein isolated from root.

[摘要] The cytoplasmic proteins from root of six crop plants, which showed various degree of tolerance to highly acidic soil, were divided into Fraction I and Fraction II. The characters of these fractions are summarized as follows: (1) Concerning the electrophoretic patterns of Fr. I, migration distance toward the positive side decreased in the followinc order : rice ≒ buckwheat < maize < sorghum < tobacco < mint. The plants of less lime requirement showed shorter distance with the exception of tobacco. (2) The amount of Ca or Al uptake by one mg. of Fr. I increased in the same order as that of the distance in the pattern obtained with Fr. I of the six crops except tobacco. (3) As the root contained Fr. I much more than Fr. II, Ca or Al uptake by root is considered to be due principally to binding with Fr. I based on the formula, (cation uptake by one mg. Fr. I or II) × (percentage of Fr. I or II in root). (4) The migration distance of Fr. I from plants susceptible to soil acidity such as sorghum and mint decreased with changing pH values from 8.9 to 6.1 and the depression of Ca uptake of the two crops showed the same tendency. (5) No relationship was noticed between the patterns of Fr. II and the lime requiremnt, and also no relationship was seen between the patterns of Fr. II and Al or Ca uptake per one mg. of Fr. II protein. (6) The tolerance of the crop plants to soil acidity seemed primarily due number of negatively charged carboxyl sites and others in Fr. I of the root. In tobacco plants, the experiment suggested that the free site of Fr. I protein readily bound each other as a result of electrostatic reaction. (7) The experiment also showed that slight absorption of phosphate occurred by Fr. I protein and this fact suggests that the phosphate uptake by root is not closely related with Fr.I protein.

[学科分类] 农业科学（综合）