Burkholderia phytofirmans sp. nov., a novel plant-associated bacterium with plant-beneficial properties

Abstract

A Gram-negative, non-sporulating, rod-shaped, motile bacterium, with a single polar flagellum, designated strain PsJN T , was isolated from surface-sterilized onion roots. This isolate proved to be a highly effective plant-beneficial bacterium, and was able to establish rhizosphere and endophytic populations associated with various plants. Seven related strains were recovered from Dutch soils. Based on 16S rRNA gene sequence data, strain PsJN T and the Dutch strains were identified as representing a member of the genus Burkholderia, as they were closely related to Burkholderia fungorum (98?7 %) and Burkholderia phenazinium (98?5 %). Analysis of whole-cell protein profiles and DNA-DNA hybridization experiments confirmed that all eight strains belonged to a single species. Strain PsJN T had a DNA G+C content of 61?0 mol%. Only low levels of DNA-DNA hybridization to closely related species were found. Qualitative and quantitative differences in fatty acid composition between strain PsJN T and closely related species were identified. The predominant fatty acids in strain PsJN T were 16 : 0, 18 : 1v7c and summed feature 3 (comprising 16 : 1v7c and/or iso-15 : 0 2-OH). Isolate PsJN T showed high 1-aminocyclopropane-1-carboxylate deaminase activity and is therefore able to lower the ethylene level in a developing or stressed plant. Production of the quorum-sensing signal Abbreviations: ACC, 1-aminocyclopropane-1-carboxylate; GFP, green fluorescent protein; NAHL, N-acyl-homoserine lactone.The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of B. phytofirmans strains PsJN T , G44-5 and G6-5 are AY497470, AY836218 and AY836219.A neighbour-joining tree showing the position of B. phytofirmans sp. nov. within the genus Burkholderia, a dendrogram derived from the protein patterns of the strains studied and cross-sections showing chickpea roots with strain PsJN T

Microbial Assisted Foliar Feeding of Micronutrients Enhance Growth, Yield and Biofortification of Wheat

“…Burkhuldaria phytofirmans (PsJN) stimulate the growth of many plant species including grapevine, tomato potato and many other plants. This is might be due to production of ACC deaminase, phytohormones including auxins and gibberellic acid, nutrients solublization, nitrogen fixation activity and organic acids production (Sessitsch et al, 2005). The hormone production might be considered possible mechanism behind root growth and development.…”

Potential of Bacterial Endophytes as Plant Growth Promoting Factors

“…Except for already established seed-endophytes [38] the most common mode of entry of endophytic bacteria into plant tissues is through primary and lateral root cracks, and diverse tissue wounds occurring as a result of plant growth [39]. Because root wounds allow the leakage of plant metabolites, they become sites that attract bacteria [12].…”

The impact of three bacteria isolated from contaminated plant cultures on in vitro multiplication and rooting of microshoots of four ornamental plants

“…Only C. pusillum affected all four species in the same way, but M. extorquens had a positive effect only on hosta and gerbera, and P. glucanolyticus only on chrysanthemum. In comparison, Burkholderia phytophirmans PsJN™ seems to have an exceptional genotype, because of its wide range of host plants (Sessitsch et al 2005).…”

“…The best-known candidate for biotization is the Burkholderia phytofirmans PsJN TM strain, formerly named Pseudomonas spp. PsJN, which does not grow on the plant medium in the absence of plant explants (Sessitsch et al 2005). It colonizes both the surface and the internal tissues (Frommel et al 1991;Nowak 1998), and stimulates the growth of microshoots and microroots, makes the use of water more efficient and increases the plant resistance to pathogens (Sharma & Nowak 1998;Theocharis et al 2012) and coldness .…”