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Characterizing nicotianamine aminotransferase: Improving its assay system and details of the regulation of its activity by Fe nutrition status
| Content Provider | Scilit |
|---|---|
| Author | Kanazawa, Kenji Higuchi, Kyoko Nakanishi, Hiromi Kishi-Nishizawa, Naoko Mori, Satoshi |
| Copyright Year | 1998 |
| Description | Under iron deficient conditions, graminaceous plants secrete mugineic acid family phytosiderophores (MAs) from their roots to dissolve sparingly soluble iron compounds in the rhizosphere, and take up iron in the form of an $Fe^{3+}$-MAs complex (Takagi 1976). A good correlation has been reported between the tolerance of Fe-deficiency and the amount of secreted MAs (Takagi 1993). Therefore, by using the genes involved in MAs biosynthesis, molecular breeding might produce transgenic plants tolerant to Fe-deficiency with a high level of MAs secretion. The biosynthetic pathway of MAs from L-methionine has been clarified (Fig. 1) and the enzymes participating in this process are now being investigated to isolate the genes responsible. Nicotianamine aminotransferase (NAAT) catalyzes the amino group transfer between nicotianamine (NA) and 2-oxoglutaric acid (Fig. 1). In order to purify NAAT, enzyme assay methods for NAAT have been developed and modified (Shojima et al. 1990; Ohata et al. 1993; Kanazawa et al. 1994). Some characteristics of NAAT have been reported using these enzyme assay methods (Kanazawa et al. 1994, 1995). Here, we further investigate some characteristics of this enzyme to improve the enzyme assay method, namely 1) the effect of $K^{+}$ and $Mg^{2+}$ on NAAT activity in vitro, and 2) the direct influence of MAs, $Fe^{3+}$, and $Fe^{2+}$ on NAAT activity. In addition, based on these results, the induction of enzyme activity by Fe-deficiency and suppression of the activity by Fe-resupply was investigated, by applying the new enzyme assay method. |
| Related Links | https://www.tandfonline.com/doi/pdf/10.1080/00380768.1998.10414499?needAccess=true |
| Ending Page | 721 |
| Page Count | 5 |
| Starting Page | 717 |
| ISSN | 00380768 |
| e-ISSN | 17470765 |
| DOI | 10.1080/00380768.1998.10414499 |
| Journal | Soil Science and Plant Nutrition |
| Issue Number | 4 |
| Volume Number | 44 |
| Language | English |
| Publisher | Informa UK Limited |
| Publisher Date | 1998-12-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: Soil Science and Plant Nutrition Soil Science Barley Roots Fe-deficiency Mugineic Acid Nicotianamine Aminotransferase |
| Content Type | Text |
| Resource Type | Article |
| Subject | Soil Science Plant Science |
