EFFICIENCY OF NITROGEN-UTILIZATION IN C-3 AND C-4 CEREALS
EFFICIENCY OF NITROGEN-UTILIZATION IN C-3 AND C-4 CEREALS
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DOI：
10.1104/pp.106.2.407
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发表时间：
1994-10-01
期刊：
影响因子：
7.4
通讯作者：
OAKS, A
中科院分区：
文献类型：
--
作者：
OAKS, A
图1.一氧化氮同化的主要反应。A，NO3-+ Gln; B，Gln和谷氨酸的潜在命运。在B中列出的某些反应中，NH 4+可以取代Gln，例如在Asn、氨甲酰磷酸或谷氨酸的合成中。在这些替代反应中，还需要不同的基因产物。当光呼吸被抑制时，组织NOS-的积累减少，这表明真正的体内NOS-还原直接或间接地被光呼吸产生的产物抑制，并且通过通常的体外和体内方法测量的NR活性反映了组织NO 3-的水平，而不一定是体内还原NO 3-的能力。也就是说，NO_3 ~-诱导的NR蛋白总量并不一定表示为原位NR活性。根据目前的研究，该蛋白质的可变量在任何时候都处于活性形式（见Lillo，1994）。Thi; NR的活化潜力可能是Hageman实验中发现的产量和氮添加量之间相关性较差的原因之一（Hageman和Lambert，1988）。
Figure 1. Primary reactions in the assimilation of NO,-. A, NO3-+ Gln; B, potential fates of Gln and glutamate. In some of the reactions listed in B, NH4+ may substitute for Gln, eg in the synthesis of Asn, carbamoylphosphate, or glutamate. In these alternative reactions distinct gene products are also required. accumulation of tissue Nos-, which is reduced when photorespiration is inhibited, suggests that the true in vivo reduction of Nos-is inhibited either directly or indirectly by a product or products resulting from photorespiration, and that the NR activity as measured by the usual in vitro and in vivo methods reflects levels of tissue NO3-and not necessarily the hue in vivo capacity for the reduction of NO3-. In other words, the total leve1 of NR protein induced by NO3-is not necessarily expressed as NR activity in situ. According to current research, variable amounts of that protein are in an active form at any one time (see Lillo, 1994). Thi; activation potential of NR could be one reason for the poor correlations found between yield and nitrogen additions in Hageman's experiments (Hageman and Lambert, 1988).