Tryptophan-Dependent Production of Indole-3-Acetic Acid (IAA) Affects Level of Plant Growth Promotion by Bacillus amyloliquefaciens FZB42
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2007Cita bibliográfica
Idris, E. E., Iglesias, D. J., Talon, M., & Borriss, R. (2007). Tryptophan-dependent production of indole-3-acetic acid (IAA) affects level of plant growth promotion by Bacillus amyloliquefaciens FZB42. Molecular plant-microbe interactions, 20(6), 619-626.Abstract
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.