scholarly journals Indole-3-Acetic Acid Produced by Burkholderia heleia Acts as a Phenylacetic Acid Antagonist to Disrupt Tropolone Biosynthesis in Burkholderia plantarii

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Mengcen Wang ◽  
Seiji Tachibana ◽  
Yuta Murai ◽  
Li Li ◽  
Sharon Yu Ling Lau ◽  
...  

Abstract Burkholderia heleia PAK1-2 is a potent biocontrol agent isolated from rice rhizosphere, as it prevents bacterial rice seedling blight disease caused by Burkholderia plantarii. Here, we isolated a non-antibacterial metabolite from the culture fluid of B. heleia PAK1-2 that was able to suppress B. plantarii virulence and subsequently identified as indole-3-acetic acid (IAA). IAA suppressed the production of tropolone in B. plantarii in a dose-dependent manner without any antibacterial and quorum quenching activity, suggesting that IAA inhibited steps of tropolone biosynthesis. Consistent with this, supplementing cultures of B. plantarii with either L-[ring-2H5]phenylalanine or [ring-2H2~5]phenylacetic acid revealed that phenylacetic acid (PAA), which is the dominant metabolite during the early growth stage, is a direct precursor of tropolone. Exposure of B. plantarii to IAA suppressed production of both PAA and tropolone. These data particularly showed that IAA produced by B. heleia PAK1-2 disrupts tropolone production during bioconversion of PAA to tropolone via the ring-rearrangement on the phenyl group of the precursor to attenuate the virulence of B. plantarii. B. heleia PAK1-2 is thus likely a microbial community coordinating bacterium in rhizosphere ecosystems, which never eliminates phytopathogens but only represses production of phytotoxins or bacteriocidal substances.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Poovarasan Neelakandan ◽  
Chiu-Chung Young ◽  
Asif Hameed ◽  
Yu-Ning Wang ◽  
Kui-Nuo Chen ◽  
...  

AbstractTea leaves possess numerous volatile organic compounds (VOC) that contribute to tea’s characteristic aroma. Some components of tea VOC were known to exhibit antimicrobial activity; however, their impact on bacteria remains elusive. Here, we showed that the VOC of fresh aqueous tea leaf extract, recovered through hydrodistillation, promoted cell division and tryptophan-dependent indole-3-acetic acid (IAA) production in Pseudomonas sp. NEEL19, a solvent-tolerant isolate of the tea phylloplane. 1-octanol was identified as one of the responsible volatiles stimulating cell division, metabolic change, swimming motility, putative pili/nanowire formation and IAA production, through gas chromatography-mass spectrometry, microscopy and partition petri dish culture analyses. The bacterial metabolic responses including IAA production increased under 1-octanol vapor in a dose-dependent manner, whereas direct-contact in liquid culture failed to elicit such response. Thus, volatile 1-octanol emitting from tea leaves is a potential modulator of cell division, colonization and phytohormone production in NEEL19, possibly influencing the tea aroma.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 761
Author(s):  
Sang-Mo Kang ◽  
Saqib Bilal ◽  
Raheem Shahzad ◽  
Yu-Na Kim ◽  
Chang-Wook Park ◽  
...  

Information on the use of endophytic bacteria as a bio-herbicide for the management of weed control in agricultural fields is limited. The current study aimed to isolate endophytic bacteria from evening primroses and to screen them for their bio-herbicidal activity. Two isolated endophytic bacteria (Pantoea dispersa YNA11 and Klebsiella pneumoniae YNA12) were initially screened for citrate utilization and for indole-3-acetic acid (IAA) and catalase production. The preliminary biochemical assessment showed YNA12 as a positive strain. Ammonia, catalase, and IAA in its culture filtrate were quantified. Gas Chromatography/Mass Spectroscopy- Selective Ion Monitoring (GC/MS-SIM) analysis revealed the production of IAA by YNA12 in a time-dependent manner. YNA12 also exhibited significant ammonia-producing potential and catalase activity against hydrogen peroxide. The YNA12 culture filtrate significantly inhibited the germination rate of evening primrose seeds, resulting in a marked reduction in seedling length and biomass compared with those of the control seeds. Moreover, the culture filtrate of YNA12 significantly accelerated the endogenous abscisic acid (ABA) production and catalase activity of evening primrose seedlings. Macronutrient regulation was adversely affected in the seedlings exposed to the culture filtrate of YNA12, leading to inhibition of seed germination. The current results suggest that endophytic YNA12 may be used as a potent bio-herbicidal agent for controlling weed growth and development.


2019 ◽  
Vol 5 (1) ◽  
pp. 18-23
Author(s):  
Selina Kabir ◽  
Ronok Zahan ◽  
Abdullah Mohammad Sarwaruddin Chowdhury ◽  
Choudhury Mahmood Hasan ◽  
Mohammad Abdur Rashid

Background: Polyalthia simiarum (Hook. F. &Thomson) exhibits different effects in human body. Objective: As a part of ongoing research on medicinal plants of Bangladesh, the present study is focused to investigate the analgesic and anti-inflammatory activities of stem bark of Polyalthia simiarum (Annonaceae). Methodology: The ethyl acetate (EA) and petroleum ether (PE) extracts were subjected to qualitative chemical investigation for the identification of different phytoconstituents. The analgesic activity was determined for its central and peripheral pharmacological actions using tail immersion method and acetic acid-induced writhing test. The anti-inflammatory activity was evaluated by carrageenan induced paw edema in rats. Analgesic and anti-inflammatory data were evaluated statistically analysed by Dunnett’s-T test. Result: Both extracts at the dose of 50- and 100 mg/kg b.w., produced significant increase in pain threshold in tail immersion method whereas significantly reduced the writhing caused by acetic acid in a dose dependent manner. The EA and PE extracts showed anti-inflammatory activities at 50- and 100 mg/kg body weight. Among all the extracts, the EA extract showed a dose dependent and comparable analgesic activity in all the tested methods and also reduced the paw edema considerably (27.5% and 39.1% inhibition after 4h), in dose dependent manner when compared to carrageenan induced control rat. Conclusion: Therefore, the EA and PE extracts of Polyalthia simiarum were capable to exhibit moderate analgesic and anti-inflammatory activities. This is the first report of analgesic and anti-inflammatory potential of Polyalthia simiarum and can be further investigated to isolate the active compounds responsible for the biological activities. Journal of National Institute of Neurosciences Bangladesh, 2019;5(1): 18-23


1970 ◽  
Vol 1 (1) ◽  
pp. 6-11
Author(s):  
Moli Akter ◽  
Mirola Afroze ◽  
Ambia Khatun

The present study was carried out to investigate the possible analgesic, neuropharmacological and cytotoxic activities of the methanolic extract of Trigonella foenum-graecum Linn. leaves. The analgesic and neuropharmacological activities of Trigonella foenum-graecum Linn. were investigated at the doses of 100mg/kg, 200mg/kg and 400mg/kg of body weight in mice. Analgesic potential of the extract was evaluated for centrally acting analgesic property using tail immersion method and peripheral analgesic actions using acetic acid-induced writhing test. In acetic acid-induced writhing test, extract produced a significant (p < 0.001) inhibition of writhing response in a dose dependent manner but maximum inhibition (93.46%) of writhing was found at 400mg/kg dose. In tail immersion method, extract caused a significant (p < 0.001) increase in latency time and the results were comparable to the standard drug Diclofenac- Sodium. In addition, neuropharmacological property of crude extract was carried out by Hole cross and Open field test. The extract significantly (p < 0.05-0.001) displayed a dose dependent suppression of motor activity, exploratory behaviour. Furthermore, the extract was subjected to Brine Shrimp lethality bioassay for primary evaluation of cytotoxicity, where the extract was found to be highly toxic to Brine Shrimp nauplii, having LC50 values of 10μg/ml while the LC50 of the reference anticancer drug vincristine sulphate was 0.66μg/ml. The results of this present study suggest that the extract possesses analgesic, cytotoxic and CNS depressant activities. Key Words: Trigonella foenum-graecum Linn.; cytotoxicity; neuropharmacological; analgesic activity. DOI: http://dx.doi.org/10.3329/icpj.v1i1.9218 International Current Pharmaceutical Journal 2011, 1(1): 6-11


1988 ◽  
Vol 255 (1) ◽  
pp. F135-F141
Author(s):  
K. Golchini ◽  
I. Kurtz

The pathway for NH3 permeation across the apical membrane of MDCK cells was determined by measuring the effect of membrane fluidizing agents, protein reactive agents, and temperature on cellular NH3 influx. The rate of NH3 influx was calculated from the time course of increase in intracellular pH (pHi), measured with 2,7-biscarboxyethyl-5(6)-carboxyfluorescein, when MDCK cell monolayers were exposed to NH4Cl. The apical membrane NH3 permeability was 7.13 +/- 0.37 x 10(-3) cm/s (n = 12) at 37 degrees C and 1.23 +/- 0.07 x 10(-3) cm/s (n = 7) at 18 degrees C. In comparison, apical membrane permeability at 37 degrees C to the weak acids, valeric acid and acetic acid, were 1.39 +/- 0.11 x 10(-2) cm/s (n = 4) and 6.93 +/- 0.11 x 10(-3) cm/s (n = 4), respectively. The activation energy for NH3 permeation was 15.0 +/- 1.0 kcal/mol (17.5 degrees C-37.5 degrees C). In the presence of the membrane fluidizing agents, heptanol or chloroform, NH3 permeability increased in a dose-dependent manner. Heptanol (15 mM) significantly decreased the activation energy for NH3 permeation to 4.4 +/- 0.6 kcal/mol, P less than 0.001. The carboxyl reactive agent (1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide metho-p-toluensulfonic acid 1 mM), aminoreactive agents (4,4'-diisothiocyanostilbene-2,2'-disulfonic acid 50 microM; picrylsulphonic acid 1 mM), the sulphydryl reactive agent (p-chloromercuriphenylsulfonic acid 1 mM), and the nonspecific membrane protein cleaving agent pronase (1 mg/ml) had no effect on the NH3 influx. The results suggest that NH3 permeates the plasma membrane of MDCK cells via a lipid pathway.


1974 ◽  
Vol 31 (3) ◽  
pp. 357-365 ◽  
Author(s):  
S. Kristensen

1. Ruminal metabolism of labelled phenylacetic acid, 4-hydroxyphenylacetic acid, indole-3-acetic acid, glucose, shikimic acid, phenol, and serine was studied in vitro by short-term incubation with special reference to incorporation rates into aromatic amino acids.2. Earlier reports on reductive carboxylation of phenylacetic acid and indole-3-acetic acid in the rumen were confirmed and the formation of tyrosine from 4-hydroxyphenylacetic acid was demonstrated for the first time.3. The amount of phenylalanine synthesized from phenylacetic acid was estimated to be 2 mg/1 rumen contents per 24 h, whereas the amount synthesized from glucose might be eight times as great, depending on diet.4. Shikimic acid was a poor precursor of the aromatic amino acids, presumably owing to its slow entry into rumen bacteria.5. A slow conversion of phenol into tyrosine was observed.


2021 ◽  
Author(s):  
Lihong Dong ◽  
Qing Shen ◽  
Cheng-Yen Chen ◽  
Lizheng Shen ◽  
Fan Yang ◽  
...  

Auxin is an important phytohormone regulating plant growth and development, and can also be produced by microbial pathogens including the rice-blast fungus Magnaporthe oryzae. However, the detailed biosynthesis pathway, biological function(s), and cellular distribution of such fungal auxin in M. oryzae remain largely unknown. Here, we report a sequential accumulation of intrinsic auxin in the three conidial cells, the infection structure (appressorium), and the invasive hyphae in M. oryzae. Such fungus-derived auxin was also secreted out and perceived by the host plants. A mitochondria-associated Indole-3-pyruvate decarboxylase, Ipd1, is essential for auxin/Indole-3-acetic acid biosynthesis in M. oryzae. The ipd1 mutant was defective in pathogenicity whereas overexpression of IPD1 led to enhanced virulence in rice. Chemical inhibition of fungal IAA biosynthesis, or its increase via external supplementation decreased or increased the severity of blast disease, respectively, in a dose-dependent manner. Furthermore, the IAA produced and secreted by M. oryzae governed the incidence and severity of blast disease in a quorum-dependent manner. Appressorium formation, conidial cell death critical for appressorium function, and the transcription of infection-related genes, MPG1 and INV1, directly correlated with cell density and/or IAA levels within the conidial population at the early stages of pathogenic development. Overall, our study revealed that the severity of blast disease is regulated via quorum sensing with intrinsic IAA serving as an associated signal transducer in rice blast.


Author(s):  
Jagan Nadipelly ◽  
Vijaykumar Sayeli ◽  
Parimala Kadhirvelu ◽  
Jaikumar Shanmugasundaram ◽  
Binoy Varghese Cheriyan ◽  
...  

AbstractThe present study was designed to investigate the anti-nociceptive activity of a few structurally related trimethoxy flavones (7,2′,3′-TMF, 7,2′,4′-TMF, 7,3′,4′-TMF and 7,5,4′-TMF) and the possible mechanisms involved.Anti-nociceptive activity was evaluated in mice by employing acetic acid-induced writhing, formalin-induced nociception and hot water tail immersion methods. The involvement of opioid, GABAergic, tryptaminergic, adrenergic and dopaminergic mechanisms and KTrimethoxy flavones exhibited a significant and dose-dependent inhibition of acetic acid writhing. The paw-licking response time was reduced both in the early and late phases of formalin nociception in a dose-dependent manner by trimethoxy flavones. A significant increase in tail withdrawal latency time was also observed after trimethoxy flavones treatment. These observations revealed the potential anti-nociceptive action of the investigated trimethoxy flavones. Pretreatment with naloxone and bicuculline significantly attenuated the reduction of abdominal constrictions produced by all the tested trimethoxy flavones indicating a definite role of opioid and GABAergic mechanisms in the anti-nociceptive effect of trimethoxy flavones. The anti-nociceptive action elicited by various trimethoxy flavones was differently modulated by glibenclamide, ondansetron, yohimbine and sulpiride.The investigated trimethoxy flavones exhibited promising anti-nociceptive activity in various nociceptive models, and multiple mechanisms are involved in the anti-nociceptive activity of these compounds.


2015 ◽  
Vol 18 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Md Al Faruk ◽  
Mohammad Firoz Khan ◽  
Md Yeunus Mian ◽  
Mohammad Sharifur Rahman ◽  
Mohammad A Rashid

Aganosma dichotoma (Roth) K. Schum. is an indigenous plant of Bangladesh. Traditional healers use this plant to treat many diseases. In order to systematically explore the medicinal values of this plant, the crude methanol extract of leaves of A. dichotoma were screened for analgesic and antidiarrheal activities in mice model. The peripheral and central analgesic actions were determined by using acetic acid-induced writhing and tail immersion methods. The extract significantly (p < 0.05) attenuated the acetic acid-induced writhing in a dose dependent manner. A noticeable dose-dependent increase (p < 0.05) of latency period was also observed in the tail immersion method. In the castor oil induced anti-diarrheal assay, the extract exhibited significant (p < 0.05) anti-diarrheal effect at a dose of 400 mg/kg body weight.Bangladesh Pharmaceutical Journal 18(1): 15-19, 2015


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