Guan Miao, Schjoerring Jan K
a Department of Plant and Environment Sciences & Copenhagen Plant Science Center , Faculty of Science, University of Copenhagen , Thorvaldsensvej , Frederiksberg C , Denmark.
b Laboratory of In Vitro Diagnostic Technology, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences , China.
Plant Signal Behav. 2016 Nov;11(11):e1245253. doi: 10.1080/15592324.2016.1245253.
Cytosolic glutamine synthetase 1;2 plays an important role in the primary nitrogen assimilation in roots. Based on characterization of the knockout mutant gln1;2 we have recently demonstrated that Gln1;2 is also essential for ammonium handling in shoots. Here we built reciprocally grafted plants between wild type (Wt) and gln1;2 in order to separate the root and shoot roles of Gln1;2. Significant reduction in silique number and seed yield were observed in the grafted plants 1;2/Wt relative to Wt/1;2 and Wt/Wt. Shoot Gln1;2 thus played a crucial role for seed production. Tracing experiments with N showed that the relative nitrogen remobilization from vegetative organs to seeds in gln1;2 was just as efficient as in the Wt plants. This was the case although the total quantity of nitrogen in gln1;2 was significantly lower compared to that in the Wt. We conclude that the functions of shoot Gln1;2 are primarily associated with internal N signaling for establishment of seed yield capacity rather than with nitrogen remobilization.
细胞质谷氨酰胺合成酶1;2在根的初级氮同化中起重要作用。基于对敲除突变体gln1;2的表征，我们最近证明Gln1;2对地上部铵的处理也至关重要。在这里，我们构建了野生型（Wt）和gln1;2之间的相互嫁接植株，以区分Gln1;2在根和地上部的作用。相对于Wt/1;2和Wt/Wt，在嫁接植株1;2/Wt中观察到角果数和种子产量显著降低。因此，地上部Gln1;2对种子生产起关键作用。用N进行的追踪实验表明，gln1;2中从营养器官到种子的相对氮再转运与野生型植株一样有效。尽管gln1;2中的总氮量与野生型相比显著降低，但情况依然如此。我们得出结论，地上部Gln1;2的功能主要与建立种子产量能力的内部氮信号有关，而不是与氮再转运有关。
