News & Notes Indole Acetic Acid and Its Metabolism in Root Nodules of a Monocotyledonous Tree Roystonea regia

1998 ◽  
Vol 37 (2) ◽  
pp. 137-140 ◽  
Author(s):  
Priti S. Basu ◽  
Atish C. Ghosh
Keyword(s):  
Acetic Acid ◽  
Indole Acetic Acid ◽  
Root Nodules

scholarly journals Production and Metabolism of Indole Acetic Acid in Root Nodules and Symbiont (Rhizobium undicola) Isolated from Root Nodule of Aquatic Medicinal Legume Neptunia oleracea Lour.

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Pallab Kumar Ghosh ◽  
Tarun Kumar De ◽  
Tushar Kanti Maiti
Keyword(s):  
Acetic Acid ◽  
Indole Acetic Acid ◽  
Root Nodules ◽  
Acc Deaminase ◽  
Vital Role ◽  
Metabolizing Enzymes ◽  
16S Rdna Sequence ◽  
Plant Microbe Interaction ◽  
Iaa Production ◽  
Pgpr Traits

Indole acetic acid is a phytohormone which plays a vital role in plant growth and development. The purpose of this study was to shed some light on the production of IAA in roots, nodules, and symbionts of an aquatic legume Neptunia oleracea and its possible role in nodular symbiosis. The symbiont (N37) was isolated from nodules of this plant and identified as Rhizobium undicola based on biochemical characteristics, 16S rDNA sequence homology, and DNA-DNA hybridization results. The root nodules were found to contain more IAA and tryptophan than root; however, no detectable amount of IAA was found in root. The IAA metabolizing enzymes IAA oxidase, IAA peroxidase (E.C.1.11.1.7), and polyphenol oxidase (E.C.1.14.18.1) were higher in root than nodule but total phenol and IAA content were reversed. The strain N37 was found to produce copious amount of IAA in YEM broth medium with tryptophan and reached its stationary phase at 20 h. An enrichment of the medium with mannitol, ammonium sulphate, B12, and 4-hydroxybenzaldehyde was found to promote the IAA production. The presence of IAA metabolizing enzymes and IAA production with PGPR traits including ACC deaminase activity of the symbionts was essential for plant microbe interaction and nodule function.

scholarly journals Isolation,Characterization and Optimization of Wild Type Sinorhizobium meliloti to Produce High Concentrations of Indole Acetic Acid

2021 ◽  
pp. 1415-1422
Author(s):  
Ibtihal Idrees Kanaan ◽  
Najwa Ibrahim Khaleel Al-Barhawee
Keyword(s):  
Acetic Acid ◽  
Sinorhizobium Meliloti ◽  
Indole Acetic Acid ◽  
Root Nodules ◽  
Biochemical Properties ◽  
Wild Type ◽  
High Production ◽  
High Concentrations ◽  
Layer Chromatography ◽  
Better Than

Rhizobium bacteria was isolated from the root nodules of Medicago sativa plants and, based on morphological and some biochemical properties, it was characterized as Sinorhizobium meliloti. We studied the ability of this isolate, as well as that of Agrobacterium rhizogenes R1601, to produce the auxin  indole acetic acid (IAA). For purposes of control, both isolates, in the absence of tryptophan-L, were similarly tested. The identification of IAA was achieved by checking the colour reactions with Salkowski’s reagent. Low amounts (23, 69 and 26,77 µɡ/ml) of IAA were produced by S.meliloti and A.rhizogenes after 24 and 72 hours of incubation, respectively. S.meliloti was distinguished by the high production of this auxin (612µg/ml) when adding 0.1% tryptophan to the growth medium (YEM), as compared to the amount of its production by the other bacteria. Therefore, this isolation was used to determine the highest production of IAA at optimal conditions, which reached to 553,550 and 610,662 µg/ml in liquid YEM medium supported with tryptophan-L (both at 0.5 and 1.0%)  and a medium supported with glucose and lactose sugar (10%), after 72 hours of incubation, respectively. The 72-hour incubation period was better than that of 24-hour in obtaining an additional amount of IAA, which ranged between 0.6 and 0.7g/l. A spot of IAA produced by rhizobium bacteria was created corresponding to the standard spot of IAA in the thin layer chromatography (TLC) detection experiment.

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