Enhanced production of indole-3-acetic acid by a genetically modified strain of Pseudomonas fluorescens CHA0 affects root growth of cucumber, but does not improve protection of the plant against Pythium root rot

The biocontrol strain CHA0 of Pseudomonas fluorescens produces small amounts of indole-3-acetic acid via the tryptophan side chain oxidase and the tryptophan transaminase pathways. A recombinant plasmid (pME3468) expressing the tryptophan monooxygenase pathway was introduced into strain CHA0; this resulted in elevated synthesis of indole-3-acetic acid in vitro, especially after addition of l-tryptophan. In natural soil, strain CHA0/pME3468 increased fresh root weight of cucumber by 17-36%, compared to the effect of strain CHA0; root colonization was about 106 cells per g of root. However, both strains gave similar protection of cucumber against Pythium ultimum. In autoclaved soil, at 6×107 cells per g of root, strain CHA0 stimulated growth of roots and shoots, whereas strain CHA0/pME3468 caused root stunting and strong reduction of plant weight. These results are in agreement with the known effects of exogenous indole-3-acetic acid on plant roots and suggest that in the system examined, indole-3-acetic acid does not contribute to the biocontrol properties of strain CHA

Identification of New Metabolites of Bacterial Transformation of Indole by Gas Chromatography-Mass Spectrometry and High Performance Liquid Chromatography

Arthrobacter sp. SPG transformed indole completely in the presence of an additional carbon source. High performance liquid chromatography and gas chromatography-mass spectrometry detected indole-3-acetic acid, indole-3-glyoxylic acid, and indole-3-aldehyde as biotransformation products. This is the first report of the formation of indole-3-acetic acid, indole-3-glyoxylic acid, and indole-3-aldehyde from indole by any bacterium

Effect of Indole Acetic Acid on Wheat (Triticum aestivum L.) Irrigated with Sewage Water

A field experiment was conducted to study the accumulation of heavy metals by winter wheat (Triticum aestivum L.) variety PBW-343 grown under sewage water (collected from Harun Nagla channel of Bareilly city, U.P., India.) of two different concentrations (50% and 100%). Effects of indole-3- acetic acid (IAA) of two different concentrations (10ppm and 20ppm) were applied after 25, 50, 75 and 100days of seed germination. The quantities of heavy metals like Pb, Cr, Zn, Cu and Fe were determined at physiological maturity in wheat plant. Indole-3- acetic acid treatment alleviated the adverse effect of toxic heavy metals contents of sewage water due to production of enzymatic and non-enzymatic antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), carotenoids, and proline respectively, and enhanced the plant growth and yield of wheat. The 100% concentration of sewage water with 20ppm of Indole-3- acetic acid showed decrease in uptake of heavy metals like Cr, Pb whereas an increase in Zn, Cu, Fe uptake was noticed with 10ppm of Indole-3- acetic acid and 100% concentration of sewage water by wheat grains

The Effect of Indole-3-Acetic Acid (IAA) on the Activity Levels of Dehydrogenases in the Silkgland of Silkworm, Bombyx Mori L

The effect of indole-3-acetic acid (IAA) on the glucose-6-phosphate dehydrogenase (G-6-PDH),lactate dehydrogenase (LDH), glutamate dehydrogenase (GDH), iso-citrate dehydrogenase (ICDH), succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) were studied The stimulation of G-6-PDH activity in the silk gland of experimental larva indicates increased oxidation of glucose resulting in higher levels of NADPH. Increased G-6-PDH activity in the present study suggests this as compensatory mechanism to maintain the structural complexity, functional integrity and metabolic centrality of the cells The activity of LDH, ICDH, MDH and SDH were increased in the silk gland of IAA treated larvae. The increased activity of the dehydrogenases may be attributed to increased turnover of aminoacids and oxidative metabolism in the silk gland. The activity level of GDH was increased in silk gland which indicates the increased oxidation of glutamate

In vitro culture of Piper attenuatum Ham. (Piperaceae): Callus induction and plant regeneration

Callus induction and plant regeneration of Piper attenuatum was achieved from stem explants in Murashige and Skoog and Gamborg's basal media supplemented with 2,4-dichlorophenoxyacetic acid, indole-3-acetic acid, Kinetin, benzyladenine and palmyarh (Borassus flabelliferl endosperm extract. Root induction was obtained from stem explants in Murashige and Skoog medium supplemented with a-naphthaleneacetic acid, b-naphthoxyacetic acid, indole-3-acetic acid, benzyladenine, kinetin and coconut water. Shoot development was achieved in in vitro rooted stem segments planted in Murashige and Skoog's medium supplemented with indole-3-acetic acid, benzyladenine and also in indole-3-acetic acid and kinetin. The plantlets were successfully established in soil. This is the first report of in vitro culture of P. attenuatum. &nbsp

Cultural Physiology: Effect of Plant Growth Hormones on the Growth and Sporulation of Aspergillus umbrosus

On the growth and sporulation of Aspergillus umbrosus (Bainier and Sartory) the effect of different plant growth hormones taken for studies, those were; indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), napthyl acetic acid (NAA), gibberllic acid (GA), 6-benzyl adenine (BA) and kinetin. In each case the hormones were sterilized and filtration and added in the medium in 10, 15, 20 and 25 ppm concentrations after autoclaving. Results after experiments indicated that the plant growth hormones were adverse for the growth and sporulation of the fungus

Chlorinated auxins–how does Arabidopsis thaliana deal with them?

Plant hormones have various functions in plants and play crucial roles in all developmental and differentiation stages. Auxins constitute one of the most important groups with the major representative indole-3-acetic acid (IAA). A halogenated derivate of IAA, 4-chloro-indole-3-acetic acid (4-Cl-IAA), has previously been identified in Pisum sativum and other legumes. While the enzymes responsible for the halogenation of compounds in bacteria and fungi are well studied, the metabolic pathways leading to the production of 4-Cl-IAA in plants, especially the halogenating reaction, are still unknown. Therefore, bacterial flavin-dependent tryptophan-halogenase genes were transformed into the model organism Arabidopsis thaliana. The type of chlorinated indole derivatives that could be expected was determined by incubating wild type A. thaliana with different Cl-tryptophan derivatives. We showed that, in addition to chlorinated IAA, chlorinated IAA conjugates were synthesized. Concomitantly, we found that an auxin conjugate synthetase (GH3.3 protein) from A. thaliana was able to convert chlorinated IAAs to amino acid conjugates in vitro. In addition, we showed that the production of halogenated tryptophan (Trp), indole-3-acetonitrile (IAN) and IAA is possible in transgenic A. thaliana in planta with the help of the bacterial halogenating enzymes. Furthermore, it was investigated if there is an effect (i) of exogenously applied Cl-IAA and Cl-Trp and (ii) of endogenously chlorinated substances on the growth phenotype of the plants

Gut microbiota generation of protein-bound uremic toxins and related metabolites is not altered at different stages of chronic kidney disease see

Chronic kidney disease (CKD) is characterized by accumulation of protein-bound uremic toxins such as p-cresyl sulfate, p-cresyl glucuronide, indoxyl sulfate and indole-3-acetic acid, which originate in the gut. Intestinal bacteria metabolize aromatic amino acids into p-cresol and indole, (further conjugated in the colon mucosa and liver) and indole-3-acetic acid. Here we measured fecal, plasma and urine metabolite concentrations; the contribution of gut bacterial generation to plasma protein-bound uremic toxins accumulation; and influx into the gut of circulating protein-bound uremic toxins at different stages of CKD. Feces, blood and urine were collected from 14 control individuals and 141 patients with CKD. Solutes were quantified by ultra-high performance liquid chromatography. To assess the rate of bacterial generation of p-cresol, indole and indole-3-acetic acid, fecal samples were cultured ex vivo. With CKD progression, an increase in protein-bound uremic toxins levels was observed in plasma, whereas the levels of these toxins and their precursors remained the same in feces and urine. Anaerobic culture of fecal samples showed no difference in ex vivo p-cresol, indole and indole-3-acetic acid generation. Therefore, differences in plasma protein-bound uremic toxins levels between different CKD stages cannot be explained by differences in bacterial generation rates in the gut, suggesting retention due to impaired kidney function as the main contributor to their increased plasma levels. Thus, as fractional clearance decreased with the progression of CKD, tubular clearance appeared to be more affected than the glomerular filtration rate, and there was no net increase in protein-bound uremic toxins influx into the gut lumen with increased plasma levels

Micropropagation and shoot regeneration from leaf and nodal explants of peppermint (Mentha piperita L.)

A two step procedure for in vitro plant regeneration of a commercial cultivar (MP-l) of peppermint Mentha piperita is described. Nodal explants cultured on Murashige and Skoog medium supplemented with kinetin (2-3 mgl-1) and indole-3-acetic acid (1 mgl-1) or 6-benzyl- aminopurine (2-3 mgl-1) and indole-3-acetic acid (0.25 mgl-1) produced multiple axillary and adventitious shoots which rooted on Murashige and Skoog' medium containing 0.25 mgI-' indole-3-acetic acid. In vitro plantlets also served as source for leaf explants. Morphogenetic responses of leaf explants were growth regulator dependent and exhibited a broad maxima over a range of growth regulator levels tested. Optimal regeneration of shoot buds was observed on Murashige and Skoog media supplemented with kinetin (3 mgl-1) and indole-3-acetic acid (1 mgl-1) or 6-benzylaminopurine (2-3 mgl-1) and indole-3-acetic acid (1 mgl-1) or a-naphthaleneacetic acid (0.25 mgl-1). These plantlets exhibited a high rate (98 per cent) of survival under glass house and field conditions. &nbsp

Synthesis and antioxidant evaluation of novel indole-3-acetic acid analogues

Indole-3-acetic acid (1) on reaction with thionyl chloride, afforded 2-(1H-indol-3-yl)acetyl chloride (2), which was further treated with aniline and various substituted anilines through base condensation reaction to obtain respected indole-3-acetic acid derivatives (3-9). The structures of all new compounds were elucidated by elemental analysis, Mass, IR, 1H NMR and 13C NMR and spectroscopic techniques. All the compounds were screened for their antioxidant activities by applying in vitro methods like 2,2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging assay and inhibition of microsomal lipid peroxidation (LPO) assay. Butylated hydroxy anisole (BHA) was used as a reference antioxidant compound and the comparative study with newly synthesized compounds was also done. Among the analogues, compound 9 bearing electron donating methoxy substituent in addition to the phenolic moiety showed predominant activity. It is conceivable from these studies that the coupling of aniline and substituted anilines is the most important feature for the significant antioxidant activity of indole-3-acetic acid analogues studied