Tryptophan conversion to indole-3-acetic acid via indole-3-acetamide in Azospirillum brasilense Sp7

1993 ◽  
Vol 39 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Tami Bar ◽  
Yaacov Okon
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Azospirillum Brasilense ◽  
Soil Bacteria ◽  
Plant Interactions ◽  
Monooxygenase Activity ◽  
Azospirillum Brasilense Sp7 ◽  
Indole 3 Acetic Acid ◽  
Induced Proteins

The phytohormone indole-3-acetic acid is involved in several types of microorganism-plant interactions. In the most widely studied pathway, tryptophan-2-monooxygenase converts tryptophan to the intermediate indole-3-acetamide, and indole-3-acetamide hydrolase catalyzes the conversion of indole-3-acetamide to indole-3-acetic acid. The genetic determinants for these enzymatic conversions are iaaM and iaaH, respectively. This pathway has been observed in many pathogenic and symbiotic soil bacteria. The associative soil bacteria of the genus Azospirillum are known to promote plant growth, probably via the secretion of phytohormones, including indole-3-acetic acid. The following evidence is presented for the existence of the above-described indole-3-acetic acid pathway in Azospirillum brasilense Sp7: the high toxicity of α-methyltryptophan as compared with that of 5-methyltryptophan; indole-3-acetic acid formation in vivo from indole-3-acetamide; the existence of two tryptophan-induced proteins, one of which has a molecular weight similar to that of tryptophan-2-monooxygenase; tryptophan-2-monooxygenase activity observed on nondenaturing gel; the existence of a protein with high tryptophan-2-monooxygenase activity with a molecular weight similar to that of one of the tryptophan-induced proteins on a two-dimensional gel; and the partial homology between the iaaM gene, which encodes tryptophan-2-monooxygenase in Pseudomonas savastanoi, and A. brasilense Sp7 total DNA.Key words: Azospirillum brasilense Sp7, indole-3-acetic acid, tryptophan, indole-3-acetamide.

scholarly journals The ectopic expression of Arabidopsis glucosyltransferase UGT74D1 affects leaf positioning through modulating indole-3-acetic acid homeostasis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shanghui Jin ◽  
Bingkai Hou ◽  
Guizhi Zhang
Keyword(s):  
Acetic Acid ◽  
Ectopic Expression ◽  
Leaf Angle ◽  
Kinase Substrate ◽  
Auxin Distribution ◽  
Leaf Tissues ◽  
Photosynthesis Efficiency ◽  
Indole 3 Acetic Acid

AbstractLeaf angle is an important agronomic trait affecting photosynthesis efficiency and crop yield. Although the mechanisms involved in the leaf angle control are intensively studied in monocots, factors contribute to the leaf angle in dicots are largely unknown. In this article, we explored the physiological roles of an Arabidopsis glucosyltransferase, UGT74D1, which have been proved to be indole-3-acetic acid (IAA) glucosyltransferase in vitro. We found that UGT74D1 possessed the enzymatic activity toward IAA glucosylation in vivo and its expression was induced by auxins. The ectopically expressed UGT74D1 obviously reduced the leaf angle with an altered IAA level, auxin distribution and cell size in leaf tissues. The expression of several key genes involved in the leaf shaping and leaf positioning, including PHYTOCHROME KINASE SUBSTRATE (PKS) genes and TEOSINTE BRANCHED1, CYCLOIDEA, and PCF (TCP) genes, were dramatically changed by ectopic expression of UGT74D1. In addition, clear transcription changes of YUCCA genes and other auxin related genes can be observed in overexpression lines. Taken together, our data indicate that glucosyltransferase UGT74D1 could affect leaf positioning through modulating auxin homeostasis and regulating transcription of PKS and TCP genes, suggesting a potential new role of UGT74D1 in regulation of leaf angle in dicot Arabidopsis.

A Prototype Model for Indole-3-Acetic Acid (IAA) Production by Azospirillum brasilense SP245

2004 ◽  
Vol 37 (9) ◽  
pp. 493-498 ◽  
Author(s):  
Ilse Y. Smets ◽  
Kristel Bernaerts ◽  
Astrid Cappuyns ◽  
Ositadinma Ona ◽  
Jos Vanderleyden ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Azospirillum Brasilense ◽  
Prototype Model ◽  
Iaa Production ◽  
Indole 3 Acetic Acid

scholarly journals Indole-3-Acetic Acid Improves Postharvest Biological Control of Blue Mold Rot of Apple by Cryptococcus laurentii

2009 ◽  
Vol 99 (3) ◽  
pp. 258-264 ◽  
Author(s):  
Ting Yu ◽  
Jishuang Chen ◽  
Huangping Lu ◽  
Xiaodong Zheng
Keyword(s):  
Acetic Acid ◽  
Apple Fruit ◽  
Natural Resistance ◽  
Penicillium Expansum ◽  
Cryptococcus Laurentii ◽  
Blue Mold ◽  
Biocontrol Efficacy ◽  
Indole 3 Acetic Acid

Cryptococcus laurentii is a well-known postharvest biocontrol yeast; however, it cannot provide satisfactory levels of decay control when used alone. Here, we evaluated the effects of indole-3-acetic acid (IAA), a plant growth regulator, on the biocontrol efficacy of the yeast antagonist C. laurentii against blue mold rot caused by Penicillium expansum in apple fruit. Results showed that the addition of IAA at 20 μg/ml to suspensions of C. laurentii greatly enhanced inhibition of mold rot in apple wounds compared with that observed with C. laurentii alone. The addition of IAA at 20 μg/ml or lower did not influence the population growth of C. laurentii in wounds, but adverse effects were seen on C. laurentii when the concentration of IAA was increased to 200 μg/ml or above in vitro and in vivo. P. expansum infection in apple wounds was not inhibited when the pathogen was inoculated into the fruit wounds within 2 h after application of IAA; however, infection was reduced when inoculated more than 12 h after IAA application. Treatment of wounds with IAA at 20 μg/ml 24 h before pathogen inoculation resulted in significant inhibition of P. expansum spore germination and host infection. Application of IAA at 20 μg/ml also reduced P. expansum infection when it was applied 48 h before pathogen inoculation in the intact fruit. Thus, IAA could reinforce the biocontrol efficacy of C. laurentii in inhibiting blue mold of apple fruit by induction of the natural resistance of the fruit.

Indole-3-acetic acid: a reciprocal signalling molecule in bacteria–plant interactions

2000 ◽  
Vol 8 (7) ◽  
pp. 298-300 ◽  
Author(s):  
Mark Lambrecht ◽  
Yaacov Okon ◽  
Ann Vande Broek ◽  
Jos Vanderleyden
Keyword(s):  
Acetic Acid ◽  
Plant Interactions ◽  
Signalling Molecule ◽  
Indole 3 Acetic Acid

scholarly journals Indole-3-acetic acid is a physiological inhibitor of TORC1 in yeast

PLoS Genetics ◽  
2021 ◽  
Vol 17 (3) ◽  
pp. e1009414
Author(s):  
Raffaele Nicastro ◽  
Serena Raucci ◽  
Agnès H. Michel ◽  
Michael Stumpe ◽  
Guillermo Miguel Garcia Osuna ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Cell Communication ◽  
Physiological Role ◽  
Eukaryotic Cell ◽  
Yeast Cells ◽  
Metabolic Inhibitor ◽  
Quiescent State ◽  
Indole 3 Acetic Acid

Indole-3-acetic acid (IAA) is the most common, naturally occurring phytohormone that regulates cell division, differentiation, and senescence in plants. The capacity to synthesize IAA is also widespread among plant-associated bacterial and fungal species, which may use IAA as an effector molecule to define their relationships with plants or to coordinate their physiological behavior through cell-cell communication. Fungi, including many species that do not entertain a plant-associated life style, are also able to synthesize IAA, but the physiological role of IAA in these fungi has largely remained enigmatic. Interestingly, in this context, growth of the budding yeast Saccharomyces cerevisiae is sensitive to extracellular IAA. Here, we use a combination of various genetic approaches including chemical-genetic profiling, SAturated Transposon Analysis in Yeast (SATAY), and genetic epistasis analyses to identify the mode-of-action by which IAA inhibits growth in yeast. Surprisingly, these analyses pinpointed the target of rapamycin complex 1 (TORC1), a central regulator of eukaryotic cell growth, as the major growth-limiting target of IAA. Our biochemical analyses further demonstrate that IAA inhibits TORC1 both in vivo and in vitro. Intriguingly, we also show that yeast cells are able to synthesize IAA and specifically accumulate IAA upon entry into stationary phase. Our data therefore suggest that IAA contributes to proper entry of yeast cells into a quiescent state by acting as a metabolic inhibitor of TORC1.

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