scholarly journals Erratum to: Contribution of indole-3-acetic acid in the plant growth promotion by the rhizospheric strain Bacillus amyloliquefaciens SQR9

2015 ◽  
Vol 51 (3) ◽  
pp. 331-331 ◽  
Author(s):  
Jiahui Shao ◽  
Zhihui Xu ◽  
Nan Zhang ◽  
Qirong Shen ◽  
Ruifu Zhang
2007 ◽  
Vol 20 (6) ◽  
pp. 619-626 ◽  
Author(s):  
ElSorra E. Idris ◽  
Domingo J. Iglesias ◽  
Manuel Talon ◽  
Rainer Borriss

Phytohormone-like acting compounds previously have been suggested to be involved in the phytostimulatory action exerted by the plant-beneficial rhizobacterium Bacillus amyloliquefaciens FZB42. Analyses by high-performance liquid chromatography and gas chromatography-mass spectrometry performed with culture filtrates of FZB42 demonstrated the presence of indole-3-acetic acid (IAA), corroborating it as one of the pivotal plant-growth-promoting substances produced by this bacterium. In the presence of 5 mM tryptophan, a fivefold increase in IAA secretion was registered. In addition, in the trp auxotrophic strains E101 (ΔtrpBA) and E102 (ΔtrpED), and in two other strains bearing knockout mutations in genes probably involved in IAA metabolism, E103 (ΔysnE, putative IAA transacetylase) and E105 (ΔyhcX, putative nitrilase), the concentration of IAA in the culture filtrates was diminished. Three of these mutant strains were less efficient in promoting plant growth, indicating that the Trp-dependent synthesis of auxins and plant growth promotion are functionally related in B. amyloliquefaciens.


1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes

Early seedling root growth of the nonlegumes canola (Brassica campestris cv. Tobin, Brassica napus cv. Westar) and lettuce (Lactuca saliva cv. Grand Rapids) was significantly promoted by inoculation of seeds with certain strains of Rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. The growfh-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. Auxotrophic Rhizobium mutants requiring tryptophan or adenosine (precursors for indole-3-acetic acid and cytokinin synthesis, respectively) did not promote growth to the extent of the parent strain. The findings of this study demonstrate a new facet of the Rhizobium–plant relationship and that Rhizobium leguminosarum can be considered a plant growth-promoting rhizobacterium (PGPR).Key words: Rhizobium, plant growth-promoting rhizobacteria, PGPR, indole-3-acetic acid, cytokinin, roots, auxotrophic mutants.


2013 ◽  
Vol 26 (5) ◽  
pp. 546-553 ◽  
Author(s):  
Ana Zúñiga ◽  
María Josefina Poupin ◽  
Raúl Donoso ◽  
Thomas Ledger ◽  
Nicolás Guiliani ◽  
...  

Although not fully understood, molecular communication in the rhizosphere plays an important role regulating traits involved in plant–bacteria association. Burkholderia phytofirmans PsJN is a well-known plant-growth-promoting bacterium, which establishes rhizospheric and endophytic colonization in different plants. A competent colonization is essential for plant-growth-promoting effects produced by bacteria. Using appropriate mutant strains of B. phytofirmans, we obtained evidence for the importance of N-acyl homoserine lactone-mediated (quorum sensing) cell-to-cell communication in efficient colonization of Arabidopsis thaliana plants and the establishment of a beneficial interaction. We also observed that bacterial degradation of the auxin indole-3-acetic acid (IAA) plays a key role in plant-growth-promoting traits and is necessary for efficient rhizosphere colonization. Wildtype B. phytofirmans but not the iacC mutant in IAA mineralization is able to restore promotion effects in roots of A. thaliana in the presence of exogenously added IAA, indicating the importance of this trait for promoting primary root length. Using a transgenic A. thaliana line with suppressed auxin signaling (miR393) and analyzing the expression of auxin receptors in wild-type inoculated plants, we provide evidence that auxin signaling in plants is necessary for the growth promotion effects produced by B. phytofirmans. The interplay between ethylene and auxin signaling was also confirmed by the response of the plant to a 1-aminocyclopropane-1-carboxylate deaminase bacterial mutant strain.


1977 ◽  
Vol 55 (5) ◽  
pp. 574-579 ◽  
Author(s):  
T. T. Lee

The carbamate insecticide carbofuran (2,2-dimethyl-2,3-dihydrobenzofuranyl-7-N-methyl carbamate) and three of its metabolites (7-hydroxy-2,2-dimethyl-2,3-dihydrobenzofuran (III), 3,7-dihydroxy-2,2-dimethyl-2,3-dihydrobenzofuran (IV), and 3-keto-7-hydroxy-2,2-dimethyl-2,3-dihydrobenzofuran (V)) stimulated growth in the pea stem segment assay in the presence, but not absence, of a low concentration of indole-3-acetic acid (IAA). The metabolites were more active than carbofuran itself. The synergistic effect on growth was specific with IAA since it was not observed in the presence of other auxins.Metabolites III, IV, and V and, to a lesser degree, carbofuran were found to be inhibitory to IAA degradation catalyzed by pea stem tissue or purified horseradish peroxidase (EC 1.11.1.7). Comparison of the relative activities of the compounds in the inhibition of IAA degradation and in the promotion of plant growth suggests a causal relationship. The implication is that carbofuran may promote plant growth through the inhibitory action of its metabolites on enzymic breakdown of IAA, thus preserving a critical level of IAA required for growth promotion.


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