Abstract:

Oat roor tissue DNA electrophoresis, and organic acids, amino acids, soluble sugar in root exudations were compared between different N levels by using solution culture. DNA ladder appeared in proximal ends of oat roots suugested that programmed cell death happened in oat root with no N supply. Therefore the arenchyma or cavum formed in root cortex under N or P deficiencies can be deduced as results of cortical cell PCD. Additionally, the result of this research also suggested the PCD initiates in proximal part of root under N dificiency.The results that amino acids and soluble sugar concentrations in oat root exdudation under no N condition were not significantly higher than those under abundant N supplies suggested that amino acids and soluble sugar concentrations in oat root exdudation has nothing to do with root PCD. However, the reasult that more organic acids were exudated by oat roots with no N than those with N implied that organic acids exudated by oat root may relate to the PCD happened in root cortex.