Nitrogen–iron interaction as an emerging factor influencing crop productivity and nutrient use efficiency

Plants are frequently subjected to a deficiency of single or multiple nutrients, leading to an imbalance of mineral elements impacting plant growth and development. During evolution, plants acquired diverse morphological and physiological adaptations to cope with nutrient deficiencies. Increasing evidence supports the existence of multilevel interactions between mineral nutrients, in which the uptake, transport, and assimilation of a certain nutrient can be modulated by the status of other nutrients, thus allowing plants to coordinate the balance of all essential mineral elements. Among macronutrients, nitrogen (N) is the essential nutrient required in the largest amount to sustain crop productivity ( Xu et al., 2012 Xu G. Fan X. Miller A.J. Plant Nitrogen Assimilation and Use Efficiency. Annu. Rev. Plant Biol. 2012; 63: 153-182 Crossref PubMed Scopus (1316) Google Scholar ). Because of the massive input of N fertilizers, N availability is no longer a limiting factor in most agricultural systems nowadays, but the excessive application of N fertilizers leads to several environmental problems ( Sutton et al., 2011 Sutton M.A. Oenema O. Erisman J.W. Leip A. van Grinsven H. Winiwarter W. Too much of a good thing. Nature. 2011; 472: 159-161 Crossref PubMed Scopus (709) Google Scholar ). Therefore, improving N use efficiency of crops becomes an urgent task of plant breeding ( Xu et al., 2012 Xu G. Fan X. Miller A.J. Plant Nitrogen Assimilation and Use Efficiency. Annu. Rev. Plant Biol. 2012; 63: 153-182 Crossref PubMed Scopus (1316) Google Scholar ; Hu et al., 2023 Hu B. Wang W. Chen J. Liu Y. Chu C. Genetic improvement toward nitrogen-use efficiency in rice: Lessons and perspectives. Mol. Plant. 2023; 16: 64-74 Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar ).