Report on the Agricultural Experiment Stations pp. 746-747 (1905)

Transformation of nitrogenous substances in the ripening of seeds of leguminous plants, N. I. Vasilyev (Zhur. Opuitn. Agron. [Russ. Jour. Expt. Landw.] 5 (1904), No. 1, pp. 19-54)—By the investigations of Emmerling, Hornberger, and Nyedokoochayev the fact was established that in immature seeds there are present considerable quantities of nonproteid nitrogen and that the amount of this nitrogen decreases as the seeds ripen, while the proteid nitrogen, on the contrary, correspondingly increases. Moreover, Emmerling and Nyedokoochayev ascertained the decrease, in the process of ripening, of the nitrogen of certain groups of nitrogenous crystalline substances, such as the amido acids, asparagin, and the nitrogenous substances of a basic character. The author has made a study to determine which nitrogenous substances are found in the unripe seeds, and the present article is a contribution to the solution of this problem.

In 1900 and 1901 experiments were made with the seeds of Lupinus angustifolius and Robinia pseudoacacia. From the unripe seeds of these plants were isolated various amido acids, asparagin, and the hexose bases, histidin and arginin. In 1902 the author made more detailed experiments with the seeds of Lupinus allnu and L. hileus, operating with considerably larger quantities. In the unripe seeds of these plants the absence of tyrosin was demonstrated, as was also the case with the other plants named. Phenylalanin was isolated and identified with certainty. This amido acid appears to be accompanied by amidovaleric acid. The bases histidin and arginin were separated in crystalline form. In the process of ripening, the accumulation of proteid bodies takes place at the expense of amido acids, asparagin, and the hexose bases.

The author concludes that the process of ripening is essentially the inverse of germination. While in the process of the germination of the seeds the stored-up proteid substances are transformed into nitrogenous crystalline compounds, such as amido acids, amids, and organic bases, which then appear in the germ, in the process of ripening of seeds the crystalline nitrogenous compounds (amido acids, asparagin, and the hexose bases) pass from the plant into the seeds, where they are converted into stored-up proteid substances. It may perhaps be assumed that the transportation of the albumen produced in the leaves proceeds in the form of those crystalline compounds which in the leguminous plants arrive first at the husks and then at the seeds, where they are again transformed into albumen.— P. Fireman.

Study of the variation in seeds during ripening, G. André (Compt. Rend. Acad. Sci. [Paris], 138 (1904), Nos. 24. pp. 1510-1512; 26, pp. 1713-1714).—For a considerable time the author has been studying the changes which take place in the seed of lupines, beans, and maize, from the time of their earliest formation until after maturity. Among the changes he found a progressive transformation of soluble carbohydrates into insoluble ones, a process which is the inverse of that taking place during germination. The total amount of nitrogen in proportion to the dry weight of the seed increases with the age of the seed, but the relative percentage is greatest when the seeds are quite young, and also as they approach maturity. The water content of the seeds and pods, or cob in the case of maize, was determined, and its relative amount and fluctuation at different stages of growth are shown.

In the second paper the author notes the changes which take place in the mineral matter of the seeds in a similar way. Tables are given showing that the total ash increases with the advance in maturity up to a certain point, after which there is a steady diminution. This applies strictly in the case of the ash of the pods of lupine and bean and also the ash of the lupine seed, but not for the beans, in which the ash content continued to increase up to the last observation. With the maize there was a progressive increase, but the cob was not fully mature at the last observation.

The relative proportion of mineral matter in the pods increased to the end. The variation in the lime, magnesia, potash, and phosphoric acid content was noted. The relative quantity of lime and magnesia increased progressively in the lupines and beans until approaching maturity, when there was a falling off of about one-fourth in the lime content and a less amount in the magnesia content. In the maize cobs these elements continued to increase until maturity. The potash content continually increased in the pods, cobs, and seed of each species. The amount of phosphoric acid in the dry matter increased in the pods for a while, after which it diminished. The phosphoric acid content in the seed increased continuously, there seeming to be a transfer of this compound from pod to seed, like that from leaves as they approach maturity. Similar results are noted for the grain and cob of maize.

The author proposes to continue these investigations, taking up the changes of organic compounds during the process of ripening.