Strategies for engineering improved nitrogen use efficiency in crop plants via redistribution and recycling of organic nitrogen

• Published in: Current opinion in biotechnology Vol. 73; pp. 263 - 269
• Main Authors: Melino, Vanessa J, Tester, Mark A, Okamoto, Mamoru
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2022
• Subjects: autophagy; biotechnology; catabolism; crops; Crops, Agricultural - genetics; Crops, Agricultural - metabolism; Edible Grain - metabolism; Fertilizers; genetic variation; grain protein; grain yield; Nitrogen - metabolism; nitrogen fertilizers; nutrient use efficiency; organic nitrogen; population distribution; protein content; RNA; transcription (genetics); ureides
• DOI: 10.1016/j.copbio.2021.09.003
• ISSN: 0958-1669; 1879-0429

[Display omitted] •Manipulation of ureide and amino acid transporters changes whole plant distribution of nitrogen and improves NUE.•Nitrogen from macromolecules can be recycled via selective autophagy pathways with greatest benefits under N stress.•Targeting alleles regulating plant responses to nitrogen may improve grain protein content. Global use of nitrogen (N) fertilizers has increased sevenfold from 1960 to 1995 but much of the N applied is lost to the environment. Modifying the temporal and spatial distribution of organic N within the plant can lead to improved grain yield and/or grain protein content for the same or reduced N fertilizer inputs. Biotechnological approaches to modify whole plant distribution of amino acids and ureides has proven successful in several crop species. Manipulating selective autophagy pathways in crops has also improved N remobilization efficiency to sink tissues whilst the contribution of ribophagy, RNA and purine catabolism to N recycling in crops is still too early to foretell. Improved recycling and remobilization of N must exploit N-stress responsive transcriptional regulators, N-sensing or phloem-localized promotors and genetic variation for N-responsive traits.