Dear Colleagues,

Nitrogen (N) is an essential element for life and plants are no exception. N₂ is abundant in the atmosphere, but is also biological inert. Plants acquire the N they need for primary metabolism from the soil and from nitrogen-fixing bacteria in the form of biologically-reactive (or fixed) molecules, such as ammonia, nitrate, urea, and amino acids. Nitrogen availability directly effects plant growth, for agriculturally relevant plants, fixed-nitrogen levels directly influences yield of biomass and grain. Fixed nitrogen tends to be a scarce resource in non-fertilized soils, while in fertilized soils (from either manure or synthetic N-fertilizers), nitrogen tends to be applied at high levels, causing an over-abundance of N that the crop plants cannot take up fully. On both a local and global scale, this means that fixed nitrogen distribution is low in some regions and high in others resulting in plants that are either starved for nitrogen and produce low yields or plants that cannot utilize all the available N causing environmentally damaging nitrogen pollution in our waterways and atmosphere.

As a group, plant nitrogen metabolism scientists are researching how nitrogen is taken up, how metabolism is regulated on both a cellular and developmental level, what enzymatic pathways are used, and how nitrogen is stored and remobilized from source to sink tissues. We investigate nitrogen metabolism and agronomy, and nitrogen use efficiency and yield studies. Researchers are also studying the interactions between plants and soil microbes, rhizosphere microbes, and plant microbiome species, and how these associations and commensalism benefit plant nitrogen metabolism. Other researchers investigate ways to improve N metabolism using plant breeding, biotechnology, and synthetic biology.

This Special Issue is aimed at establishing a wide collection of articles (original research papers, hypotheses, opinions, reviews, modeling approaches and methods) that focus on the process of nitrogen metabolism from many different aspects, including, but not limited to, molecular biology, biotechnology, synthetic biology, plant microbiome, biological nitrogen fixation and plants, nitrogen use efficiency, whole plant and root studies, senescence, agronomics, field trials and transcriptome, proteome, metabolome and epigenome studies. Additionally,, this Special Issue will bring together articles researching crop plants, native species, model plants, aquatic plants and trees. We are particularly interested in receiving contributions that address plant nitrogen metabolism in ways that allow fellow colleagues to gain insight into advancing their own research and further our collective understanding of this complex and essential metabolism.

Dr. Perrin H Beatty
Dr. Mei Han
Guest Editor

• Nitrogen metabolism
• Nitrogen use efficiency
• Nitrogen uptake efficiency
• nitrogen utilization efficiency
• Nitrogen remobilization
• Nitrogen regulation
• agronomy
• Nitrogen and yield
• microbiome
• plant breeding
• biotechnology
• Nitrogen and roots
• Nitrogen and senescence
• transcriptome
• proteome
• metabolome
• epigenome
• crop plants
• native species
• aquatic plants
• trees