Nitrogen fixation in a landrace of maize is supported by a mucilage-associated diazotrophic microbiota

作者：Allen Van Deynze, Pablo Zamora, Pierre‐Marc Delaux, Cristobal Heitmann, Dhileepkumar Jayaraman, Shanmugam Rajasekar, Danielle Graham, Junko Maëda, Donald Gibson, Kevin D. Schwartz, Alison M. Berry, Srijak Bhatnagar, Guillaume Jospin, Aaron E. Darling, Richard Jeannotte, Javier Rodríguez López, Bart C. Weimer, Jonathan A. Eisen, Howard-Yana Shapiro, Jean‐Michel Ané, A. B. Bennett · 发表于：PLoS Biology · 年份：2018 · DOI：10.1371/journal.pbio.2006352 · 被引用次数：402 · 研究领域：Legume Nitrogen Fixing Symbiosis、Plant nutrient uptake and metabolism、Nematode management and characterization studies

Plants are associated with a complex microbiota that contributes to nutrient acquisition, plant growth, and plant defense. Nitrogen-fixing microbial associations are efficient and well characterized in legumes but are limited in cereals, including maize. We studied an indigenous landrace of maize grown in nitrogen-depleted soils in the Sierra Mixe region of Oaxaca, Mexico. This landrace is characterized by the extensive development of aerial roots that secrete a carbohydrate-rich mucilage. Analysis of the mucilage microbiota indicated that it was enriched in taxa for which many known species are diazotrophic, was enriched for homologs of genes encoding nitrogenase subunits, and harbored active nitrogenase activity as assessed by acetylene reduction and 15N2 incorporation assays. Field experiments in Sierra Mixe using 15N natural abundance or 15N-enrichment assessments over 5 years indicated that atmospheric nitrogen fixation contributed 29%-82% of the nitrogen nutrition of Sierra Mixe maize.