论文部分内容阅读
通过~(15)N硝酸盐示踪,说明大豆植株所需的氮来源于N_2与NO_3。大豆植株在初花期和鼓粒初期收获。在茎、叶柄和叶片的尿囊素(allantoin)来源于NO_3的氮素百分率几乎与根瘤中一样;但在根部比在其它器官中的百分率高。这些结果表明大多数新梢中的尿囊素是从根瘤获得,而且尿囊素已在根中从NO_3形成,促使很少氮素输送到新梢。尿囊素在40日龄植株剥下的茎皮中是看不到的,由于尿囊素大部分经茎的木质部输出。尿囊素浓度在豆荚中特别高,被认为尿囊素氮是用于荚的蛋白质的合成。
Nitrate tracing of ~ (15) N showed that the nitrogen needed by soybean plants was derived from N_2 and NO_3. Soybean plants were harvested at the beginning of flowering and drumming. The percentage of nitrogen derived from NO 3 in the stem, petiole and leaf of allantoin is almost the same as that in nodules; however, the percentage of allantoin in roots is higher than in other organs. These results indicate that allantoin in most shoots is obtained from root nodules and that allantoin has been formed from NO 3 in roots, causing very little nitrogen to be delivered to the shoots. Allantoin can not be seen in the bark peeled off from plants on the 40th day, since most of the allantoin is output from the xylem of the stem. Allantoin concentrations are particularly high in pods, and allantoin nitrogen is thought to be the protein synthesis for pods.