BT1, a protein critical for in vivo starch accumulation in maize endosperm, is not detected in maize endosperm suspension cultures

The flavonols kaempferol, quercetin and isorhamnetin were labelled with 14C by keeping seven day old Cicer arietinum L. plants in an atmosphere of 14CO2 for five days. The purified (U-14C) flavonols were applied to cell suspension cultures of Cicer arietinum L., Phaseolus aureus Roxb., Glycine max and Petroselinum hortense. Based on the rates of 14CO2 formation and distribution of radioactivity after fractionation of the cells, the flavonols were shown to be catabolized to a very high extent.All four cell suspension cultures possess the enzymatic activity transforming flavonols to the recently discovered 2,3-dihydroxyflavanones. Upon incubation of the flavonols datiscetin and kaempferol with enzyme preparations from Cicer arietinum L. cell suspension cultures, it was demonstrated that the enzymatically formed 2,3-dihydroxyflavanones are further transformed in an enzyme catalyzed reaction. Salicylic acid was found as a degradation fragment of ring B of the 2,3,5,7,2′-pentahydroxyflavanone derived from datiscetin. Neither phloroglucinol nor phloroglucinol carboxylic acid were observed as metabolites of ring A. These in vitro findings were further substantiated by in vivo data because the flavonols kaempferol, quercetin and datiscetin when applied to cell suspension cultures of Cicer arietinum L. and Glycine max gave rise to para-hydroxybenzoic acid, protocatechuic acid and salicylic acid, respectively. It was thus concluded that flavonols are catabolized via 2,3-dihydroxyflavanones with the B-ring liberated as the respective benzoic acid. The data are discussed in connection with earlier findings on the catabolism of chalcones, cinnamic and benzoic acids.

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In vivo ANTI-INFLAMMATORY ACTIVITY AND ACUTE TOXICITY OF METHANOLIC EXTRACTS FROM WILD PLANT LEAVES AND CELL SUSPENSION CULTURES OF Buddleja cordata Kunth (Buddlejaceae)

Revista Mexicana de Ingeniería Química ◽

10.24275/uam/izt/dcbi/revmexingquim/2018v17n1/gutierrez ◽

2018 ◽

Vol 17 (1) ◽

pp. 317-330 ◽

Cited By ~ 2

Author(s):

G.A. Gutiérrez ◽

Keyword(s):

Acute Toxicity ◽

Cell Suspension ◽

Cell Suspension Cultures ◽

Suspension Cultures ◽

Inflammatory Activity ◽

Wild Plant ◽

Plant Leaves ◽

Methanolic Extracts ◽

Buddleja Cordata

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Evidence for the Participation of a 5-Oxo-prolinase in Degradation of Glutathione in Nicotiana tabacum

Zeitschrift für Naturforschung C ◽

10.1515/znc-1980-9-1008 ◽

1980 ◽

Vol 35 (9-10) ◽

pp. 708-711 ◽

Cited By ~ 12

Author(s):

Heinz Rennenberg ◽

Reinhard Steinkamp ◽

Andrea Polle

Keyword(s):

Nicotiana Tabacum ◽

Glutamic Acid ◽

Suspension Cultures ◽

Sulfur Source ◽

Tobacco Cells ◽

Tobacco Suspension Cultures

Abstract During degradation of glutathione in tobacco suspension cultures substancial amounts of 5-oxo-proline are formed in vivo as well as in crude cell homogenates in vitro. The existance of a 5-oxo-prolinase that catalyzes the conversion of 5-oxo-proline to glutamic acid was demonstrated in tobacco cells, grown with glutathione as sole sulfur source.

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Two chloroplastic PLGG1 isoforms function together to transport photorespiratory glycolate and glycerate in rice

Journal of Experimental Botany ◽

10.1093/jxb/erab020 ◽

2021 ◽

Author(s):

Lili Cui ◽

Chuanling Zhang ◽

Zhichao Li ◽

Tuxiu Xian ◽

Limin Wang ◽

...

Keyword(s):

Rice Genome ◽

Direct Interaction ◽

Crop Productivity ◽

Chloroplast Envelope ◽

Starch Accumulation ◽

Loss Of Function ◽

In Planta ◽

In Vivo Experiments

Abstract The photorespiratory pathway is highly compartmentalized. As such, metabolite shuttles between organelles are critical to ensure efficient photorespiratory carbon flux. Arabidopsis PLGG1 has been reported as a key chloroplastic glycolate/glycerate transporter. Two homologous genes OsPLGG1a and OsPLGG1b have been identified in the rice genome, although their distinct functions and relationships remain unknown. Herein, our analysis of exogenous expression in oocytes and yeast shows that both OsPLGG1a and OsPLGG1b have the ability to transport glycolate and glycerate. Furthermore, we demonstrate in planta, that the perturbation of OsPLGG1a or OsPLGG1b expression leads to extensive accumulation of photorespiratory metabolites, especially glycolate and glycerate. Under ambient CO2 conditions, loss-of-function osplgg1a or osplgg1b mutant plants exhibited significant decreases in photosynthesis efficiency, starch accumulation, plant height, and crop productivity. These morphological defects were almost entirely recovered when the mutant plants were grown under elevated CO2 conditions instead. In contrast to osplgg1a, osplgg1b mutant alleles produced a mild photorespiratory phenotype and had reduced accumulation of photorespiratory metabolites. Subcellular localization analysis showed that OsPLGG1a and OsPLGG1b are located in the inner and outer membranes of the chloroplast envelope, respectively. In vitro and in vivo experiments revealed that OsPLGG1a and OsPLGG1b have a direct interaction. Our results indicate that both OsPLGG1a and OsPLGG1b are chloroplastic glycolate/glycerate transporters required for photorespiratory metabolism and plant growth, and that they may function as a singular complex.

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