Nematicidal and Plant Growth-Promoting Activity of Enterobacter asburiae HK169: Genome Analysis Provides Insight into Its Biological Activities

Abstract

In the course of screening for microbes with nematicidal activity, we found that Enterobacter asburiae HK169 displayed promising nematicidal activity against the root-knot nematode Meloidogyne incognita, along with plant growth-promoting properties. Soil drenching of a culture of HK169 reduced gall formation by 66% while also increasing root and shoot weights by 251% and 160%, respectively, compared with an untreated control. The cell-free culture filtrate of the HK169 culture killed all juveniles of M. incognita within 48 h. In addition, the nematicidal activity of the culture filtrate was dramatically reduced by a protease inhibitor, suggesting that proteolytic enzymes contribute to the nematicidal activity of HK169. In order to obtain genomic information about the HK169 isolate related to its nematicidal and plant growth-promoting activities, we sequenced and analyzed the whole genome of the HK169 isolate, and the resulting information provided evidence that the HK169 isolate has nematicidal and plant growth-promoting activities. Taken together, these observations enable the future application of E. asburiae HK169 as a biocontrol agent for nematode control and promote our understanding of the beneficial interactions between E. asburiae HK169 and plants.

Impact of Plant Growth Promoting Rhizobacteria in the Orchestration of Lycopersicon esculentum Mill. Resistance to Plant Parasitic Nematodes: A Metabolomic Approach to Evaluate Defense Responses Under Field Conditions

“…Studies have been reported that showed a modulation in the genes involved in amino acid metabolism in nematode infested A. thaliana plants inoculated with Serratia plymuthica M24T3 [99]. Furthermore, stimulation in the activities of secondary metabolic profiles have also been reported by Oh et al [100] by Enterobacter arsburiae HK169 in nematode infected tomato plants in order to encounter the oxidative stress generated by pathogen attack. However, an upliftment in the secondary metabolic profiles have also been found in tomatoes and carrots exposed to nematode infection after the inoculation of PGPR, B. firmus T11, B. aryabhattai AO8, B. cereus , P. alvei T30 and P. barcinonensis A10 respectively [19].…”

Complete Genome Sequence of Enterobacter roggenkampii ED5, a Nitrogen Fixing Plant Growth Promoting Endophytic Bacterium With Biocontrol and Stress Tolerance Properties, Isolated From Sugarcane Root

“…The complete-genome study can be used to categorize genes implicated in the positive effects of plant growth-promoting bacteria (PGPB), offer the perception of the molecular and functional mechanisms (Kang et al, 2016;Qin et al, 2017;Oh et al, 2018). Earlier, complete genome analysis of some other Enterobacter stains is accessible (Ren et al, 2010;Taghavi et al, 2010;Liu et al, 2012;Andrés-Barrao et al, 2017) excluding E. roggenkampii.…”

Intergrated Metagenomics and Metabolomics Analysis Discovers Nematicidal Microbes, Enzymes and Metabolites From the Plant Rhizosphere Microbiota

“…Indeed, catalase activity, Alcaligenes faecalis showed toxicity against M. incognita by producing an extracellular serine protease, which can damage the intestines of nematode [37]. Enterobacter asburiae displayed promising nematicidal activity against M. incognita, and its nematicidal virulence factor was also determined as the proteolytic enzymes [58]. Rhizobacteria such as Burkholderia gladioli, Delftia acidovorans, Rhizobium etli, Pseudomonas spp.…”