Studies on the Physiological Function of the Crop Roots

Abstract

Considering that the roots are not only the organs from which absorbs the nutrients and water, but also synthesize the various chemical substances necessary for growth, authors investigated the physiological functions of the roots of the rice plant by means of the several treatments, such as the cutting off the roots, low temperature, H₂S addition to the culture solutions, and high reduction of the soil. Obtained results are as follows; 1) The cutting off the roots brings about the standstill of the plant growth and simultaneously the marked decrease in the protein content of the shoot with corresponding increase in the non protein nitrogen. 2) The roots apparently possess the functions not only absorbing the nutrients and water, but also maintaining the protein level of the plant. 3) This function is inhibited by the treatments of the roots, such as above mentioned, and the degree of the inhibition changes variously according to the kind of the treatments. 4) The results by means of the paperchromatographical analysis suggest that the protein breakdown brought by the cutting off the roots and low temperature is on account of the inhibition of the process concerning with the polymerization of the amino acids, in the case of high reduction of the soil it comes from the inhibition of the process involving many steps from the formation of α-keto acid to the transamination.