Colonization by endophytic Ochrobactrum anthropi Mn1 promotes growth of Jerusalem artichoke

Summary The Ochrobactrum anthropi Mn1 strain, taxonomically identified using 16S ribosomal DNAsequence, was isolated from roots of Jerusalem artichoke. Its endophytic colonization was investigated microscopically using green fluorescent proteinintroduced by vector pHC60. The strain entered Jerusalem artichoketissues through the root, and was localized in the roots and stems. The plant growth-promoting (PGP) effects of O. anthropi Mn1 were assessed in greenhouse as well as field trialswith different nitrogen supplies. Only under moderate to ample nitrogen supply, could O. anthropi Mn1 promoted growth of host plant. The PGP effects of the strain were symbiotic nitrogen fixation, root morphological optimization and enhanced nutrient uptake. We hypothesize that the symbiotic interspecies interaction might be quorum sensingrelated.