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Nitrogen fixation in a landrace of maize is supported by a mucilage-associated diazotrophic microbiota
Nitrogen is an essential nutrient for plants, and for many non-legume crops the requirement for nitrogen is primarily met by the use of inorganic fertilizers. These fertilizers are produced from fossil fuel by energy-intensive processes that are estimated to use 1% to 2% of the total global energy supply and produce an equivalent share of greenhouse gases. Because maize (Zea mays L.) is a significant recipient of nitrogen fertilization, a research goal for decades has been to identify or engineer mechanisms for biological fixation of atmospheric nitrogen in association with this crop. In this study by Van Deynze et al. the authors show that for one such maize landrace grown in nitrogen-depleted fields near Oaxaca, Mexico, 29%-82% of the plant nitrogen is derived from atmospheric nitrogen. High levels of nitrogen fixation are supported, at least in part, by the abundant production of a sugar-rich mucilage associated with aerial roots that provides a home to a complex nitrogen-fixing microbiome. The image shows mucilage dripping from the aerial roots of one of these plants. Van Deynze et al.
Image Credit: Howard-Jana Shapiro
Citation: (2018) PLoS Biology Issue Image | Vol. 16(8) August 2018. PLoS Biol 16(8): ev16.i08. https://doi.org/10.1371/image.pbio.v16.i08
Published: August 31, 2018
Copyright: © 2018 Shapiro. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Nitrogen is an essential nutrient for plants, and for many non-legume crops the requirement for nitrogen is primarily met by the use of inorganic fertilizers. These fertilizers are produced from fossil fuel by energy-intensive processes that are estimated to use 1% to 2% of the total global energy supply and produce an equivalent share of greenhouse gases. Because maize (Zea mays L.) is a significant recipient of nitrogen fertilization, a research goal for decades has been to identify or engineer mechanisms for biological fixation of atmospheric nitrogen in association with this crop. In this study by Van Deynze et al. the authors show that for one such maize landrace grown in nitrogen-depleted fields near Oaxaca, Mexico, 29%-82% of the plant nitrogen is derived from atmospheric nitrogen. High levels of nitrogen fixation are supported, at least in part, by the abundant production of a sugar-rich mucilage associated with aerial roots that provides a home to a complex nitrogen-fixing microbiome. The image shows mucilage dripping from the aerial roots of one of these plants. Van Deynze et al.
Image Credit: Howard-Jana Shapiro