AUTHOR=Madhaiyan Munusamy , Selvakumar Govindan , Alex Tan HianHwee , Cai Lin , Ji Lianghui 

TITLE=Plant Growth Promoting Abilities of Novel Burkholderia-Related Genera and Their Interactions With Some Economically Important Tree Species

JOURNAL=Frontiers in Sustainable Food Systems

VOLUME=Volume 5 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/sustainable-food-systems/articles/10.3389/fsufs.2021.618305

DOI=10.3389/fsufs.2021.618305

ISSN=2571-581X

ABSTRACT=A survey of bacterial endophytes associated with the leaves of oil palm and acacias resulted in the isolation of nineteen bacterial strains belonging to the genera Paraburkholderia, Caballeronia and Chitinasiproducens, which are now regarded as distinctively different from the parent genus Burkholderia. Most strains possessed one or more plant growth promotion (PGP) traits although nitrogenase activity was present in only a subset of the isolates. The diazotrophic Paraburkholderia tropica strain S39-2 with multiple PGP traits and the non-diazotrophic Chitinasiproducens palmae strain JS23T with significant level of 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity were selected to investigate the influence of bacterial inoculation on some economically important tree species. Microscopic examination revealed that Paraburkholderia tropica S39-2 was rhizospheric as well as endophytic while Chitinasiproducens palmae JS23T was endophytic. Paraburkholderia tropica strain S39-2 significantly promoted the growth of oil palm, eucalyptus and Jatropha curcas. Interestingly, the non-diazotrophic, non-auxin producing Chitinasiproducens palmae JS23T strain also significantly promoted the growth of oil palm and eucalyptus although it showed negligible effect on Jatropha curcas. Our results suggest that strains belonging to the novel Burkholderia-related genera widely promote plant growth via both N-independent and N-dependent mechanisms. Our results also suggest that the induction of defense response may prevent colonization of an endophyte in plants.