Conditions Affecting Enzyme Synthesis in Cotyledons of Germinating Seeds

Abstract

Development of phosphatase activity in cotyledons of germinating pea seeds is dependent on the presence of the axis tissue and is greatly affected by temperature. The functional integrity of the mitochondria in the cotyledons of germinating pea seeds is maintained only when axis tissues remain attached to the cotyledons. When excised pea cotyledons are incubated under germination conditions there is a rapid loss of mitochondrial function and a failure of the usual increased phosphatase activity to develop. Presumably the failure in development of the increased phosphatase activity results from the loss of energy source required for protein synthesis. Certain events which occur in cotyledons of germinating seeds appear to be under the control of a factor or factors from the axis tissue. Interestingly the patterns of phosphatase activity in cotyledons of germinating wax beans and the endosperm of castor beans are entirely different from the pattern in germinating peas.