Mechanical stimulation, 4-aminobutyric acid (GABA) synthesis, and growth inhibition in soybean hypocotyl tissue

2000 ◽  
Vol 78 (1) ◽  
pp. 119-123
Author(s):  
Alan W Bown ◽  
Guijin Zhang

4-Aminobutyric acid (GABA), a ubiquitous four-carbon nonprotein, amino acid, is synthesized via glutamate decarboxylation. It accumulates in response to mechanical stimulation through the Ca2+/calmodulin activation of glutamate decarboxylase. In this study, dark- and light-grown soybean hypocotyl tissues were used to investigate the relationship between mechanical stimulation, GABA synthesis, and growth inhibition. Mechanical stimulation through stroking resulted in a 65% growth inhibition of dark- or light-grown tissue within 1 min. The 24-h growth increment was reduced by 50% or more. Growth inhibition was accompanied by rapid 4- and 10-fold increases in GABA levels in dark- and light-grown tissue, respectively. Treatment of tissue with exogenous GABA raised GABA levels approximately 6-fold, but did not inhibit growth. In addition, lanthanum or blue light treatment of dark-grown tissue reduced growth by over 60% with no increase in GABA levels. The data demonstrate for the first time, that GABA accumulation accompanies growth inhibition occurring in response to mechanical stimulation. However, GABA accumulation alone appears insufficient to cause growth inhibition.Key words: 4-aminobutyric acid, GABA, L-Glu decarboxylase, GAD, thigmomorphogenesis, mechanical stimulation.

2001 ◽  
Vol 79 (4) ◽  
pp. 438-443
Author(s):  
David J Janzen ◽  
Lisa J Allen ◽  
Kennaway B MacGregor ◽  
Alan W Bown

The four carbon, non-protein amino acid γ-aminobutyrate (GABA) accumulates rapidly in response to diverse stresses. Its synthesis is stimulated by increases in intracellular Ca2+ or H+ levels. The pathogen-induced oxidative burst is also associated with increases in Ca2+ and H+ levels. This study investigated the relationship between GABA synthesis and the oxidative burst. A Mas-7-induced consumption of oxygen in isolated Asparagus sprengeri Regel mesophyll cells was accompanied by rapid GABA synthesis. At pH 5.0, a 300% increase occurred within 16 min from 6.6 to 26.3 nmol GABA·106 cells–1. At pH 6.0, the increase was from 8.5 to 18.1 nmol GABA·106 cells–1. Mas-7 also stimulated rapid external alkalinization and intracellular acidification. Intracellular pH decreased 0.44 pH units at pH 5.0, and 0.21 pH units at pH 6.0. The Mas-7-induced oxidative burst, GABA synthesis, extracellular alkalinization, and intracellular acidification were all eliminated when lanthanum, a Ca2+ channel blocker, replaced Ca2+ in the incubation medium. The data demonstrate that GABA accumulation is associated with the oxidative burst, and results from the fluxes of H+ and Ca2+, which are known to accompany the oxidative burst. They are discussed in light of emerging data that indicate a role for GABA in plant cell to cell signaling.Key words: γ-aminobutyric acid, GABA, oxidative burst.


2021 ◽  
Vol 174 ◽  
pp. 111446
Author(s):  
Zongyu Chi ◽  
Yuqin Dai ◽  
Shifeng Cao ◽  
Yingying Wei ◽  
Xingfeng Shao ◽  
...  

2001 ◽  
Vol 15 (6) ◽  
pp. 1089-1091 ◽  
Author(s):  
ARTUR MAYERHOFER ◽  
BARBARA HÖHNE-ZELL ◽  
KATIA GAMEL-DIDELON ◽  
HEIKE JUNG ◽  
PETER REDECKER ◽  
...  

1982 ◽  
Vol 60 (6) ◽  
pp. 850-855 ◽  
Author(s):  
Radan Čapek ◽  
Barbara Esplin

Effects of taurine and homotaurine (3-aminopropancsuIfonic acid), on excitability of primary afferents were compared with effects of γ-aminobutyric acid (GABA) in spinal unanaesthesized cats. Homotaurine and GABA, administered intravenously or topically, produced a marked increase in afferent excitability. Homotaurine was about 10 times more potent than GABA. Taurine (up to 2 mmol/kg i.v., or 10 mM topically) did not produce a consistent change in afferent excitability. The effect of homotaurine was antagonized by bicuculline or picrotoxin in doses which suppressed the primary afferent depolarization, as indicated by an increase of afferent excitability, evoked by conditioning stimulation of an antagonistic muscle nerve. Semicarbazidc, an inhibitor of GABA synthesis, did not attenuate the homotaurine-induced excitability changes of afferents while suppressing entirely the primary afferent depolarization. These findings suggest that homotaurine exerts a direct GABA-like action on feline primary afferents.


Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 401 ◽  
Author(s):  
Rosanna Tofalo ◽  
Giorgia Perpetuini ◽  
Noemi Battistelli ◽  
Alessia Pepe ◽  
Andrea Ianni ◽  
...  

The influence of calf (R1), kid (R2) and pig (R3) rennets on microbiota, biogenic amines (BAs) and γ-aminobutyric acid (GABA) accumulation in raw milk ewe’s cheeses was evaluated. Cheeses were investigated at different ripening times for their microbial composition, free amino acids (FAAs), BAs and GABA content. Moreover, the expression of tyrosine (tdc) and histidine (hdc) decarboxylases genes was evaluated by quantitative Real Time–Polymerase Chain Reaction (qRT-PCR). Microbial counts showed similar values in all samples. Pig rennet were cheeses were characterized by higher proteolysis and the highest values of BAs. The BAs detected were putrescine, cadaverine and tyramine, while histamine was absent. qRT-PCR confirmed this data, in fact hdc gene was not upregulated, while tdc gene expression increased over time in agreement with the increasing content of tyramine and the highest fold changes were detected in R3 cheeses. GABA showed the highest concentration in R2 cheeses reaching a value of 672 mg/kg. These results showed that the accumulation of BAs and GABA in Pecorino di Farindola is influenced by ripening time and type of coagulant. Further studies are required to develop starter cultures to reduce BAs content and improve health characteristics of raw milk ewe’s cheeses.


Proceedings ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 4
Author(s):  
Ersöz ◽  
Adan

Sphingolipids are important signaling lipids which play crucial roles to determine the cell fate. Ceramide, apoptotic central molecule of sphingolipid metabolism, which is produced through de novo pathway by serine palmitoyl transferase (SPT) and can be converted to antiapoptotic sphingosine-1-phosphate (S1P) and glucosyl ceramide (GC) by sphingosine kinase (SK) and glucosyl ceramide synthase (GCS), respectively. It is aimed to investigate therapeutic potential of resveratrol on FLT3-ITD (Internal Tandem Duplication) AML cells and to identify potential mechanism behind resveratrol-mediated growth inhibition by targeting of ceramide metabolism. The cytotoxic effects of resveratrol, SPT inhibitor (myricoin), SK-1 inhibitor (SKI II), GCS inhibitor (PDMP), resveratrol: SPT inhibitor, resveratrol: SK-1 inhibitor and resveratrol: GCS inhibitor combinations on MOLM-13 and MV4-11 FLT3 ITD AML cells were investigated by cell proliferation assay. Apoptosis was evaluated by annexin V/PI double staining. There were synergistic cytotoxic effects of resveratrol with co-administration of SPT inhibitor, SK-1 inhibitor and GCS inhibitor and apoptosis was synergistically induced for resveratrol and its combinations. This preliminary data showed for the first time that resveratrol might inhibit the growth of FLT3 ITD AML cells through targeting ceramide metabolism.


2007 ◽  
Vol 73 (22) ◽  
pp. 7283-7290 ◽  
Author(s):  
S. Siragusa ◽  
M. De Angelis ◽  
R. Di Cagno ◽  
C. G. Rizzello ◽  
R. Coda ◽  
...  

ABSTRACT The concentrations of γ-aminobutyric acid (GABA) in 22 Italian cheese varieties that differ in several technological traits markedly varied from 0.26 to 391 mg kg−1. Presumptive lactic acid bacteria were isolated from each cheese variety (total of 440 isolates) and screened for the capacity to synthesize GABA. Only 61 isolates showed this activity and were identified by partial sequencing of the 16S rRNA gene. Twelve species were found. Lactobacillus paracasei PF6, Lactobacillus delbrueckii subsp. bulgaricus PR1, Lactococcus lactis PU1, Lactobacillus plantarum C48, and Lactobacillus brevis PM17 were the best GABA-producing strains during fermentation of reconstituted skimmed milk. Except for L. plantarum C48, all these strains were isolated from cheeses with the highest concentrations of GABA. A core fragment of glutamate decarboxylase (GAD) DNA was isolated from L. paracasei PF6, L. delbrueckii subsp. bulgaricus PR1, L. lactis PU1, and L. plantarum C48 by using primers based on two highly conserved regions of GAD. A PCR product of ca. 540 bp was found for all the strains. The amino acid sequences deduced from nucleotide sequence analysis showed 98, 99, 90, and 85% identity to GadB of L. plantarum WCFS1 for L. paracasei PF6, L. delbrueckii subsp. bulgaricus PR1, L. lactis PU1, and L. plantarum C48, respectively. Except for L. lactis PU1, the three lactobacillus strains survived and synthesized GABA under simulated gastrointestinal conditions. The findings of this study provide a potential basis for exploiting selected cheese-related lactobacilli to develop health-promoting dairy products enriched in GABA.


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