Expression of Glucose-6-phosphate Dehydrogenase and 6-Phosphogluconate Dehydrogenase Isoform Genes in Suspension-Cultured Arabidopsis thaliana Cells

2008 ◽  
Vol 63 (9-10) ◽  
pp. 713-720 ◽  
Author(s):  
Yuling Yin ◽  
Hiroshi Ashihar
Keyword(s):  
Arabidopsis Thaliana ◽  
Stationary Phase ◽  
Transcript Accumulation ◽  
Transcript Levels ◽  
Phosphogluconate Dehydrogenase ◽  
Pi Starvation ◽  
Murashige Skoog ◽  
Almost All ◽  
Glucose 6 Phosphate Dehydrogenase

The activities of glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGDH, EC 1.1.1.44) were found to increase in suspensioncultured Arabidopsis thaliana cells after 10-day-old stationary phase cells were transferred to fresh Murashige-Skoog medium. The activities of these enzymes peaked early in the exponential growth stage of the culture (day 4) and then decreased gradually. The transcript levels of six isoform genes of G6PDH (AtG6PD1 to AtG6PD6) and three of 6PGDH (At6PGD1 to At6PGD3) were monitored during the culture. Two distinct transcript accumulation patterns were observed. In type A, the level of transcripts increased rapidly one day after the cells were inoculated into the fresh medium, and then remained almost constant until the culture reached its stationary phase (day 7). In type B, the transcripts were accumulated transiently at the first day after cell inoculation, then promptly decreased. We also investigated the effect of phosphate (Pi)-starvation and recovery on the expression of these genes. For this, the early stationary phase cultures (day 7) were transferred to fresh Pi-free culture medium. During 7 days of phosphate starvation, no growth of cultures was observed, and the transcript levels of all G6PDH and 6PGDH isoform genes were reduced, apart from one G6PDH isoform gene, AtG6PD5, which was continuously expressed throughout Pi-starvation. Compared to the reduction of almost all isoform genes of G6PDH in Pi-starved cultures, the reduction of 6PGDH genes was less severe. We discuss the localization and possible role of individual isoform genes of G6PDH and 6PGDH in connection with published databases.

scholarly journals Initial embedding of TRANSPARENT TESTA GLABRA 1 in the Arabidopsis thaliana flowering time regulatory pathway

2019 ◽  
Author(s):  
Barbara A M Paffendorf ◽  
Rawan Qassrawi ◽  
Andrea M Meys ◽  
Laura Trimborn ◽  
Andrea Schrader
Keyword(s):  
Arabidopsis Thaliana ◽  
Circadian Clock ◽  
Flowering Time ◽  
Response Regulator ◽  
Regulatory Pathway ◽  
In Planta ◽  
Transcript Levels ◽  
Transparent Testa ◽  
Flowering Locus

Pleiotropic regulatory factors mediate concerted responses of the plant’s trait network to endogenous and exogenous cues. TRANSPARENT TESTA GLABRA 1 (TTG1) is a pleiotropic regulator that has been predominantly described in its role as a regulator of early accessible developmental traits. Although its closest homologs LIGHT-REGULATED WD1 (LWD1) and LWD2 are regulators of photoperiodic flowering, a role of TTG1 in flowering time regulation has not been reported. Here we reveal that TTG1 is a regulator of flowering time in Arabidopsis thaliana and changes transcription levels of different targets within the flowering time regulatory pathway. TTG1 mutants flower early and TTG1 overexpression lines flower late at long-day conditions. Consistently, TTG1 can suppress the transcript levels of the floral integrators FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CO1 and can act as an activator of circadian clock components. Moreover, TTG1 might form feedback loops at the protein level. The TTG1 protein interacts with PSEUDO RESPONSE REGULATOR (PRR)s and basic HELIX-LOOP-HELIX 92 (bHLH92) in yeast. In planta, the respective pairs exhibit interesting patterns of localization including a recruitment of TTG1 by PRR5 to subnuclear foci. This mechanism proposes additional layers of regulation by TTG1 and might aid to specify the function of bHLH92. Within another branch of the pathway, TTG1 can elevate FLOWERING LOCUS C (FLC) transcript levels. FLC mediates signals from the vernalization, ambient temperature and autonomous pathway and the circadian clock is pivotal for the plant to synchronize with diurnal cycles of environmental stimuli like light and temperature. Our results suggest an unexpected positioning of TTG1 upstream of FLC and upstream of the circadian clock. In this light, this points to an adaptive value of the role of TTG1 in respect to flowering time regulation.

Role of hormones in glucose-6-phosphate dehydrogenase adaptation of rat liver

1962 ◽  
Vol 202 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Helen M. Tepperman ◽  
Jay Tepperman
Keyword(s):  
Food Intake ◽  
Hormone Treatment ◽  
Additional Increase ◽  
Phosphogluconate Dehydrogenase ◽  
Hypophysectomized Rats ◽  
Ad Libitum ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Determining Factor ◽  
Rule Out

The hepatic enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase increase markedly in activity on refeeding after a 48-hr fast in the intact rat, but fail to do so in the hypophysectomized animal. Treatment with somatotrophin, cortisone, and thyroid hormone individually and in pairs failed to restore this adaptation to refeeding, but a combination of the three repaired the defect. Similar observations were made on increases in these enzymes in response to fructose feeding in ad libitum-fed hypophysectomized rats. Triple hormone-treated animals in which the enzyme increase in response to fructose feeding was restored were the only ones which gained weight. To rule out possible effects of variations in food intake as a determining factor in the response, hypophysectomized rats fed measured amounts of a starch-fructose diet by stomach tube were compared with suitable controls. A striking increase in enzyme activity occurred in these animals even when no hormone treatment was given, and no additional increase could be induced by treating with the three hormones. It is concluded that the liver cell of the hypophysectomized rat has an autonomous capacity to modify its enzyme profile selectively without the direction or support of hormones of pituitary origin. These hormones may exert their effects in ad libitum-fed animals by influencing food intake and intestinal hexose absorption rates.

scholarly journals Effects of Jasmonic Acid in ER Stress and Unfolded Protein Response in Tomato Plants

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1031
Author(s):  
Zalán Czékus ◽  
Orsolya Csíkos ◽  
Attila Ördög ◽  
Irma Tari ◽  
Péter Poór
Keyword(s):  
Jasmonic Acid ◽  
Er Stress ◽  
Unfolded Protein Response ◽  
Transcript Accumulation ◽  
Chemical Chaperone ◽  
Tomato Plants ◽  
Transcript Levels ◽  
Unfolded Protein ◽  
Protein Response

Endoplasmic reticulum (ER) stress elicits a protective mechanism called unfolded protein response (UPR) to maintain cellular homeostasis, which can be regulated by defence hormones. In this study, the physiological role of jasmonic acid (JA) in ER stress and UPR signalling has been investigated in intact leaves of tomato plants. Exogenous JA treatments not only induced the transcript accumulation of UPR marker gene SlBiP but also elevated transcript levels of SlIRE1 and SlbZIP60. By the application of JA signalling mutant jai1 plants, the role of JA in ER stress sensing and signalling was further investigated. Treatment with tunicamycin (Tm), the inhibitor of N-glycosylation of secreted glycoproteins, increased the transcript levels of SlBiP. Interestingly, SlIRE1a and SlIRE1b were significantly lower in jai1. In contrast, the transcript accumulation of Bax Inhibitor-1 (SlBI1) and SlbZIP60 was higher in jai1. To evaluate how a chemical chaperone modulates Tm-induced ER stress, plants were treated with sodium 4-phenylbutyrate, which also decreased the Tm-induced increase in SlBiP, SlIRE1a, and SlBI1 transcripts. In addition, it was found that changes in hydrogen peroxide content, proteasomal activity, and lipid peroxidation induced by Tm is regulated by JA, while nitric oxide was not involved in ER stress and UPR signalling in leaves of tomato.

scholarly journals Cloning and Characterization of a Flavonol Synthase Gene fromScutellaria baicalensis

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yeon Bok Kim ◽  
KwangSoo Kim ◽  
YeJi Kim ◽  
Pham Anh Tuan ◽  
Haeng Hoon Kim ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Amino Acid ◽  
Cdna Clone ◽  
Amino Acid Residues ◽  
Anthocyanidin Synthase ◽  
Transcript Levels ◽  
Flavonol Synthase ◽  
Jelly Roll

Flavonols are the most abundant of all the flavonoids and play pivotal roles in a variety of plants. We isolated a cDNA clone encoding flavonol synthase fromScutellaria baicalensis(SbFLS). The SbFLS cDNA is 1011 bp long, encodes 336 amino acid residues, and belongs to a family of 2-oxoglutarate-dependent dioxygenases. The overall structure ofSbFLSis very similar to that ofArabidopsis thalianaanthocyanidin synthase (AtANS), with aβjelly-roll fold surrounded by tens of short and longα-helices.SbFLSwas constitutively expressed in the roots, stems, leaves, and flowers, with particularly high expression in the roots and flowers. SbFLS transcript levels in the roots were 376-, 70-, and 2.5-fold higher than in the leaves, stems, and flowers. The myricetin content was significantly higher than that of kaempferol and quercetin. Therefore, we suggest that SbFLS mediates flavonol formation in the different organs ofS. baicalensis. Our study may contribute to the knowledge of the role of FLS inS. baicalensis.

scholarly journals Activities of Catalase and Pentose Phosphate Pathway Dehydrogenases during Dormancy Release in Nectarine Seed

1990 ◽  
Vol 115 (6) ◽  
pp. 987-990 ◽  
Author(s):  
Hening Hu ◽  
Gary A. Couvillon
Keyword(s):  
Pentose Phosphate Pathway ◽  
Catalase Activity ◽  
Prunus Persica ◽  
Enzymic Activity ◽  
Pentose Phosphate ◽  
Significant Activity ◽  
Phosphogluconate Dehydrogenase ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Thiourea Treatment

The activities of catalase and of glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH), the two key enzymes in the pentose phosphate pathway (ppp), were measured in the seeds of Prunus persica (L.) Batsch var. nectarina Maxim `Nectarine 7'. The seeds were subjected to three imbibition treatments: 1) continuous 24C; 2) continuous 4C; and 3) application of thiourea (TU)/gibberellic acid (GA) at various concentrations to seed held at 24C then subsequently chilled at 4C. Treatments of continuous 24 or 4C indicated that catalase, G6PDH, and 6PGDH exhibited significant activity increases only when the seeds obtained germination potential, which occurred in the seeds chilled for 7 weeks at 4C. Seeds held at 24C did not germinate and showed little change with time in G6PDH and 6PGDH activity. There was only a slight increase in catalase activity beginning 3 weeks following treatment initiation and a decrease in activity following 13 weeks of treatment. Thiourea treatment resulted in an inhibition of catalase activity and a stimulation of G6PDH, but had no effect on 6PGDH activity. However, no correlation between enzymic activity and seed germination was found. The results strongly questioned the role of the ppp and catalase activity in dormancy control as previously hypothesized.

scholarly journals TRANSPARENT TESTA GLABRA 1 participates in flowering time regulation in Arabidopsis thaliana

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8303 ◽  
Author(s):  
Barbara A.M. Paffendorf ◽  
Rawan Qassrawi ◽  
Andrea M. Meys ◽  
Laura Trimborn ◽  
Andrea Schrader
Keyword(s):  
Arabidopsis Thaliana ◽  
Circadian Clock ◽  
Flowering Time ◽  
Response Regulator ◽  
In Planta ◽  
Transcript Levels ◽  
Autonomous Pathway ◽  
Transparent Testa ◽  
Flowering Locus

Pleiotropic regulatory factors mediate concerted responses of the plant’s trait network to endogenous and exogenous cues. TRANSPARENT TESTA GLABRA 1 (TTG1) is such a factor that has been predominantly described as a regulator of early developmental traits. Although its closest homologs LIGHT-REGULATED WD1 (LWD1) and LWD2 affect photoperiodic flowering, a role of TTG1 in flowering time regulation has not been reported. Here we reveal that TTG1 is a regulator of flowering time in Arabidopsis thaliana and changes transcript levels of different targets within the flowering time regulatory pathway. TTG1 mutants flower early and TTG1 overexpression lines flower late at long-day conditions. Consistently, TTG1 can suppress the transcript levels of the floral integrators FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CO1 and can act as an activator of circadian clock components. Moreover, TTG1 might form feedback loops at the protein level. The TTG1 protein interacts with PSEUDO RESPONSE REGULATOR (PRR)s and basic HELIX-LOOP-HELIX 92 (bHLH92) in yeast. In planta, the respective pairs exhibit interesting patterns of localization including a recruitment of TTG1 by PRR5 to subnuclear foci. This mechanism proposes additional layers of regulation by TTG1 and might aid to specify the function of bHLH92. Within another branch of the pathway, TTG1 can elevate FLOWERING LOCUS C (FLC) transcript levels. FLC mediates signals from the vernalization, ambient temperature and autonomous pathway and the circadian clock is pivotal for the plant to synchronize with diurnal cycles of environmental stimuli like light and temperature. Our results suggest an unexpected positioning of TTG1 upstream of FLC and upstream of the circadian clock. In this light, this points to an adaptive value of the role of TTG1 in respect to flowering time regulation.

The possible role of some enzymes in sclerotia formation in Aspergillus ochraceus

1983 ◽  
Vol 29 (6) ◽  
pp. 718-723 ◽  
Author(s):  
Nachman Paster ◽  
Ilan Chet
Keyword(s):  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Pentose Phosphate ◽  
Aspergillus Ochraceus ◽  
Phosphogluconate Dehydrogenase ◽  
Cycle Plays ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
The Glyoxylate Cycle

The role of some enzymes in sclerotia production by Aspergillus ochraceus was studied using a sclerotia-producing strain grown under conditions in which sclerotia production was either favoured or inhibited. In addition, a mutant strain incapable of producing sclerotia was used. No significant differences in patterns of soluble proteins, polyphenol oxidase, and esterases could be detected electrophoretically by gel electrophoresis, while the peroxidase pattern of both the sclerotia-producing strain and the mutant showed three bands as compared with two bands that appeared when sclerotia formation was inhibited. The activities of the tricarboxylic acid cycle enzymes, malate dehydrogenase and succinate dehydrogenase, and those of the pentose-phosphate pathway, glucose-6 phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, were almost identical in sclerotia- and nonsclerotia-producing mycelia. The activities of isocitrate lyase and malate synthetase, key enzymes of the glyoxylate cycle, and that of glyoxylate dehydrogenase which is related to this cycle were significantly reduced when sclerotia formation was inhibited either by methionine or by high levels of CO2. It is suggested that the glyoxylate cycle plays an important role in sclerotia formation in the fungus.

scholarly journals Initial embedding of TRANSPARENT TESTA GLABRA 1 in the Arabidopsis thaliana flowering time regulatory pathway

2019 ◽  
Author(s):  
Barbara A M Paffendorf ◽  
Rawan Qassrawi ◽  
Andrea M Meys ◽  
Laura Trimborn ◽  
Andrea Schrader
Keyword(s):  
Arabidopsis Thaliana ◽  
Circadian Clock ◽  
Flowering Time ◽  
Response Regulator ◽  
Regulatory Pathway ◽  
In Planta ◽  
Transcript Levels ◽  
Transparent Testa ◽  
Flowering Locus

Pleiotropic regulatory factors mediate concerted responses of the plant’s trait network to endogenous and exogenous cues. TRANSPARENT TESTA GLABRA 1 (TTG1) is a pleiotropic regulator that has been predominantly described in its role as a regulator of early accessible developmental traits. Although its closest homologs LIGHT-REGULATED WD1 (LWD1) and LWD2 are regulators of photoperiodic flowering, a role of TTG1 in flowering time regulation has not been reported. Here we reveal that TTG1 is a regulator of flowering time in Arabidopsis thaliana and changes transcription levels of different targets within the flowering time regulatory pathway. TTG1 mutants flower early and TTG1 overexpression lines flower late at long-day conditions. Consistently, TTG1 can suppress the transcript levels of the floral integrators FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CO1 and can act as an activator of circadian clock components. Moreover, TTG1 might form feedback loops at the protein level. The TTG1 protein interacts with PSEUDO RESPONSE REGULATOR (PRR)s and basic HELIX-LOOP-HELIX 92 (bHLH92) in yeast. In planta, the respective pairs exhibit interesting patterns of localization including a recruitment of TTG1 by PRR5 to subnuclear foci. This mechanism proposes additional layers of regulation by TTG1 and might aid to specify the function of bHLH92. Within another branch of the pathway, TTG1 can elevate FLOWERING LOCUS C (FLC) transcript levels. FLC mediates signals from the vernalization, ambient temperature and autonomous pathway and the circadian clock is pivotal for the plant to synchronize with diurnal cycles of environmental stimuli like light and temperature. Our results suggest an unexpected positioning of TTG1 upstream of FLC and upstream of the circadian clock. In this light, this points to an adaptive value of the role of TTG1 in respect to flowering time regulation.

scholarly journals The Role of Herpes Simplex Virus ICP27 in the Regulation of UL24 Gene Expression by Differential Polyadenylation

1998 ◽  
Vol 72 (10) ◽  
pp. 7709-7714 ◽  
Author(s):  
Louane E. Hann ◽  
W. James Cook ◽  
Susan L. Uprichard ◽  
David M. Knipe ◽  
Donald M. Coen
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Temporal Expression ◽  
Transcript Accumulation ◽  
Transcriptional Initiation ◽  
Transcript Levels ◽  
Infected Cells ◽  
Simplex Virus ◽  
A Site

ABSTRACT Herpes simplex virus specifies two sets of transcripts from theUL24 gene, short transcripts (e.g., 1.4 kb), processed at the UL24 poly(A) site, and long transcripts (e.g., 5.6 kb), processed at the UL26 poly(A) site. The 1.4- and 5.6-kb transcripts initiate from the same promoter but are expressed with early and late kinetics, respectively. Measurements of transcript levels following actinomycin D treatment of infected cells revealed that the 1.4- and 5.6-kb UL24 transcripts have similar stabilities, consistent with UL24 transcript kinetics being regulated by differential polyadenylation rather than by differential stabilities. Although the UL24 poly(A) site, which gives rise to short transcripts, is encountered first during processing, long transcripts processed at the UL26 site are equally or more abundant; thus, operationally, the UL24site is weak. Using a series of viral ICP27 mutants, we investigated whether ICP27, which has been suggested to stimulate the usage of weak poly(A) sites, stimulates 1.4-kb transcript accumulation. We found that accumulation of 1.4-kb transcripts did not require ICP27 during viral infection. Rather, ICP27 was required for full expression of 5.6-kb transcripts, and the decrease in 5.6-kb transcripts relative to 1.4-kb transcripts was not due solely to reduced DNA synthesis. Our results indicate that temporal expression of UL24transcripts can be regulated by differential polyadenylation and that although ICP27 is not required for processing at the operationally weakUL24 poly(A) site, it does modulate 5.6-kb transcript levels at a step subsequent to transcriptional initiation.

Sign in / Sign up

Export Citation Format

Share Document