Biological nitrogen fixation in maize: optimizing nitrogenase expression in a root-associated diazotroph
| Autor: | James G Lorigan, Sarah Bloch, Neal Shah, Megan McKellar, L Kent Wood, San-Ming Mak, Olivia Smith, Austin G. Davis-Richardson, Dominic Soriano, Alvin Tamsir, Shayin S Gottlieb, Rosemary Clark, Leslie Wu, Lorena Williams, Karsten Temme, Richard Broglie, Jenny Johnson, Alana Horton, Emily Tung, Max Petersen |
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| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Nitrogen Physiology Microorganism 030106 microbiology chemistry.chemical_element Plant Science Zea mays regulatory nodes nitrogenase expression 03 medical and health sciences Nutrient Enterobacteriaceae Nitrogen Fixation Nitrogenase Rhizosphere biology AcademicSubjects/SCI01210 Ammonium production corn rhizosphere diazotroph food and beverages biological nitrogen fixation biology.organism_classification Research Papers Kosakonia sacchari 030104 developmental biology Agronomy chemistry Nitrogen fixation Diazotroph Bacteria |
| Zdroj: | Journal of Experimental Botany |
| ISSN: | 1460-2431 0022-0957 |
| Popis: | Reprogramming the genetic regulation of nitrogen fixation and assimilation in a root-associated diazotroph to produce novel strains can restore ammonium production in the presence of exogenous nitrogen inputs. Plants depend upon beneficial interactions between roots and root-associated microorganisms for growth promotion, disease suppression, and nutrient availability. This includes the ability of free-living diazotrophic bacteria to supply nitrogen, an ecological role that has been long underappreciated in modern agriculture for efficient crop production systems. Long-term ecological studies in legume–rhizobia interactions have shown that elevated nitrogen inputs can lead to the evolution of less cooperative nitrogen-fixing mutualists. Here we describe how reprogramming the genetic regulation of nitrogen fixation and assimilation in a novel root-associated diazotroph can restore ammonium production in the presence of exogenous nitrogen inputs. We isolated a strain of the plant-associated proteobacterium Kosakonia sacchari from corn roots, characterized its nitrogen regulatory network, and targeted key nodes for gene editing to optimize nitrogen fixation in corn. While the wild-type strain exhibits repression of nitrogen fixation in conditions replete with bioavailable nitrogen, such as fertilized greenhouse and field experiments, remodeled strains show elevated levels in the rhizosphere of corn in the greenhouse and field even in the presence of exogenous nitrogen. Such strains could be used in commercial applications to supply fixed nitrogen to cereal crops. |
| Databáze: | OpenAIRE |
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