Microbes and Environments
Online ISSN : 1347-4405
Print ISSN : 1342-6311
ISSN-L : 1342-6311
Regular Papers
Nitrate Supply-Dependent Shifts in Communities of Root-Associated Bacteria in Arabidopsis
Noriyuki KonishiTakashi OkuboTomoyuki YamayaToshihiko HayakawaKiwamu Minamisawa
Author information

2017 Volume 32 Issue 4 Pages 314-323


Root-associated bacterial communities are necessary for healthy plant growth. Nitrate is a signal molecule as well as a major nitrogen source for plant growth. In this study, nitrate-dependent alterations in root-associated bacterial communities and the relationship between nitrate signaling and root-associated bacteria in Arabidopsis were examined. The bacterial community was analyzed by a ribosomal RNA intergenic spacer analysis (RISA) and 16S rRNA amplicon sequencing. The Arabidopsis root-associated bacterial community shifted depending on the nitrate amount and timing of nitrate application. The relative abundance of operational taxonomic units of 25.8% was significantly changed by the amount of nitrate supplied. Moreover, at the family level, the relative abundance of several major root-associated bacteria including Burkholderiaceae, Paenibacillaceae, Bradyrhizobiaceae, and Rhizobiaceae markedly fluctuated with the application of nitrate. These results suggest that the application of nitrate strongly affects root-associated bacterial ecosystems in Arabidopsis. Bulk soil bacterial communities were also affected by the application of nitrate; however, these changes were markedly different from those in root-associated bacteria. These results also suggest that nitrate-dependent alterations in root-associated bacterial communities are mainly affected by plant-derived factors in Arabidopsis. T-DNA insertion plant lines of the genes for two transcription factors involved in nitrate signaling in Arabidopsis roots, NLP7 and TCP20, showed similar nitrate-dependent shifts in root-associated bacterial communities from the wild-type, whereas minor differences were observed in root-associated bacteria. Thus, these results indicate that NLP7 and TCP20 are not major regulators of nitrate-dependent bacterial communities in Arabidopsis roots.

Information related to the author
© 2017 by Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions.
Previous article Next article