Summary. The changes in major nitrogenotus components during the germination of pea seeds have been followed. During the period of rapid axis growth, 3 to 8 days following germination, the nitrogen content of the cotyledons declines rapidly wvith an accompanying increase of nitrogen in the developing axis. The acculmulation of alcohol soluble nitrogen, primarily amino nitrogen, in the cotyledons and axis durinlg germination indicates that the mobilization of nitrogen is facilitated by proteolysis and translocation of the produicts.Pea cotyledons had an initially high RNA content which declined duiring germination while axis RNA increased. The increase in axis RNA was greater than the decline in cotyledonary RNA indicating a net nucleic acid synthesis. Thuis some of initial nitrogen reserve is interconverted to provide for nucleic acid synthesis.Dturing the depletion of cotyledonary RNA there was no accumulation of nucleotides in the cotyledons, nucleotide content of the axis did, however, increase during the germination period.The DNA content of the axis increased with growth of that organ. There was also an increase in DNXA content of the cotyledons dturing the early stages of germination.The principal nitrogenouis reserves of pea seeds are the globtulins, vicillin, and legim;n (6). These reserve proteins appear to be located in the cotyledon in stubcelltilar entities designated as the protein bodies (19). Dturing germination the protein bodies and reserve proteins disappear sutggesting that they are constumed to suistain the growth of the developing embryo.It is generally assulmed that the first phase of the reserve protein tutilization involves a hydrolysis of the protein to amino acids which are then transported to and incorporated into the developing embryo. In addition to suipporting the growth of the embryo it is possible that the amino acids liberated from the hydrolysis of the globulins couild be utilized for the synthesis of enzymic proteins in the cotyledons. Youing and Varner (22) interconversion of amino acids arising as hydrolytic produicts from the reserve proteins.In a stuldy of the germination of peas the change in nitrogenotus constituenits was followed in an attempt to estimate the interconversions and translocations of main nitrogenouts components. Materials and MethodsPea seeds (Pisumzt satizutmn var. Buirpeeana) were sown in moist vermicutlite (2 vermiculite :1 water w/v) and maintained in a darkened germinator at 280 for the duration of the experiments. Etiolated material was iused throutghouit the experiments.Seedlings were harvested by carefully removing the vermiculite from the root zone and separated into axis and cotyledons. The testa was removed from the seed. Fresh weights were determined immediately following harvest. This material was dried at 80°for 24 hoturs to obtain dry weight data.

No abstract

No abstract

No abstract

No abstract