Heterologous Expression of Nitrate Assimilation Related-Protein DsNAR2.1/NRT3.1 Affects Uptake of Nitrate and Ammonium in Nitrogen-Starved <i>Arabidopsis</i>
Nitrogen (N) is an essential macronutrient for plant growth. Plants absorb and utilize N mainly in the form of nitrate (NO<sub>3</sub><sup>−</sup>) or ammonium (NH<sub>4</sub><sup>+</sup>). In this study, the nitrate transporter DsNRT3.1 (also known as...
Main Authors: | , , , , , , |
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Format: | Article |
Language: | English |
Published: |
MDPI AG
2020-06-01
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Series: | International Journal of Molecular Sciences |
Subjects: | |
Online Access: | https://www.mdpi.com/1422-0067/21/11/4027 |
Summary: | Nitrogen (N) is an essential macronutrient for plant growth. Plants absorb and utilize N mainly in the form of nitrate (NO<sub>3</sub><sup>−</sup>) or ammonium (NH<sub>4</sub><sup>+</sup>). In this study, the nitrate transporter DsNRT3.1 (also known as the nitrate assimilation-related protein DsNAR2.1) was characterized from <i>Dianthus spiculifolius</i>. A quantitative PCR (qPCR) analysis showed that the <i>DsNRT3.1</i> expression was induced by NO<sub>3</sub><sup>−</sup>. Under N-starvation conditions, the transformed <i>Arabidopsis</i> seedlings expressing <i>DsNRT3.1</i> had longer roots and a greater fresh weight than the wild type. Subcellular localization showed that DsNRT3.1 was mainly localized to the plasma membrane in <i>Arabidopsis</i> root hair cells. Non-invasive micro-test (NMT) monitoring showed that the root hairs of N-starved transformed <i>Arabidopsis</i> seedlings had a stronger NO<sub>3</sub><sup>−</sup> and NH<sub>4</sub><sup>+</sup> influx than the wild-type seedlings, using with NO<sub>3</sub><sup>−</sup> or NH<sub>4</sub><sup>+</sup> as the sole N source; contrastingly, transformed seedlings only had a stronger NO<sub>3</sub><sup>−</sup> influx when NO<sub>3</sub><sup>−</sup> and NH<sub>4</sub><sup>+</sup> were present simultaneously. In addition, the qPCR analysis showed that the expression of <i>AtNRT2</i> genes (<i>AtNRT2.1</i><i>–2.6</i>), and particularly of <i>AtNRT2.5</i>, in the transformed <i>Arabidopsis</i> differed from that in the wild type. Overall, our results suggest that the heterologous expression of <i>DsNRT3.1</i> affects seedlings’ growth by enhancing the NO<sub>3</sub><sup>−</sup> and NH<sub>4</sub><sup>+</sup> uptake in N-starved <i>Arabidopsis</i>. This may be related to the differential expression of <i>AtNRT2</i> genes. |
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ISSN: | 1661-6596 1422-0067 |