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. 2022 Oct;112(2):549-564.
doi: 10.1111/tpj.15967. Epub 2022 Sep 19.

Inhibition of shoot-expressed NRT1.1 improves reutilization of apoplastic iron under iron-deficient conditions

Jia Yuan Ye  1 , Miao Zhou  1 , Qing Yang Zhu  1 , Ya Xin Zhu  1 , Wen Xin Du  1 , Xing Xing Liu  1 , Chong Wei Jin  1
Affiliations
Free article

Inhibition of shoot-expressed NRT1.1 improves reutilization of apoplastic iron under iron-deficient conditions

Jia Yuan Ye et al. Plant J. 2022 Oct.
Free article

Abstract

Iron deficiency is a major constraint for plant growth in calcareous soils. The interplay between NO3 - and Fe nutrition affects plant performance under Fe-deficient conditions. However, how NO3 - negatively regulates Fe nutrition at the molecular level in plants remains elusive. Here, we showed that the key nitrate transporter NRT1.1 in Arabidopsis plants, especially in the shoots, was markedly downregulated at post-translational levels by Fe deficiency. However, loss of NRT1.1 function alleviated Fe deficiency chlorosis, suggesting that downregulation of NRT1.1 by Fe deficiency favors plant tolerance to Fe deficiency. Further analysis showed that although disruption of NRT1.1 did not alter Fe levels in both the shoots and roots, it improved the reutilization of apoplastic Fe in shoots but not in roots. In addition, disruption of NRT1.1 prevented Fe deficiency-induced apoplastic alkalization in shoots by inhibiting apoplastic H+ depletion via NO3 - uptake. In vitro analysis showed that reduced pH facilitates release of cell wall-bound Fe. Thus, foliar spray with an acidic buffer promoted the reutilization of Fe in the leaf apoplast to enhance plant tolerance to Fe deficiency, while the opposite was true for the foliar spray with a neutral buffer. Thus, downregulation of the shoot-part function of NRT1.1 prevents apoplastic alkalization to ensure the reutilization of apoplastic Fe under Fe-deficient conditions. Our findings may provide a basis for elucidating the link between N and Fe nutrition in plants and insight to scrutinize the relevance of shoot-expressed NRT1.1 to the plant response to stress.

Keywords: Fe deficiency; Fe reutilization; NRT1.1; apoplastic pH; nitrate; shoot.

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References

REFERENCES

    1. Aitken, R.L., Moody, P.W. & McKinley, P.G. (1990) Lime requirement of acidic Queensland soils. I. Relationships between soil properties and pH buffer capacity. Soil Research, 28, 695-701. https://doi.org/10.1071/SR9900695
    1. Alber, A., Ehlting, B., Ehlting, J., Hawkins, B.J. & Rennenberg, H. (2012) Net NH4+ and NO3− flux, and expression of NH4+ and NO3− transporters in roots of Picea glauca. Trees, 26, 1403-1411. https://doi.org/10.1007/s00468-012-0700-0
    1. Barbez, E., Dünser, K., Gaidora, A., Lendl, T. & Busch, W. (2017) Auxin steers root cell expansion via apoplastic pH regulation in Arabidopsis thaliana. Proceedings of the National Academy of Sciences USA, 114, 4884-4893. https://doi.org/10.1073/pnas.1613499114
    1. Bienfait, H.F., van den Briel, W. & Mesland-Mul, N.T. (1985) Free space iron pools in roots: generation and mobilization. Plant Physiology, 78, 596-600. https://doi.org/10.1104/pp.78.3.596
    1. Bouain, N., Krouk, G., Lacombe, B. & Rouached, H. (2019) Getting to the root of plant mineral nutrition: combinatorial nutrient stresses reveal emergent properties. Trends in Plant Science, 24, 542-552. https://doi.org/10.1016/j.tplants.2019.03.008

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