scholarly journals Photometabolism of Glycollate by Euglena Gracilis

1971 ◽  
Vol 24 (1) ◽  
pp. 23 ◽  
Author(s):  
David R Murray ◽  
J Grovanelli ◽  
Robert M Smillie
Keyword(s):  
Carbon Source ◽  
Euglena Gracilis ◽  
Higher Plants ◽  
Serine Hydroxymethyltransferase ◽  
Single Source ◽  
Photosynthetic Organisms ◽  
Inhibition Of Growth ◽  
Glycollate Oxidase ◽  
Isonicotinyl Hydrazide ◽  
Glyoxylate Reductase

The photometabolism of glycollate was investigated in E. gracilis, strain Z, an organism which can utilize glycollate as a single source of carbon in the light but not in the dark. The nature of the labelled products of the photometabolism of [1-14CJglycollate, [2_14CJglycollate, and [l-14CJglycine and the inhibition of growth on glycollate by isonicotinyl hydrazide and by ex-hydroxy-2-pyridine methane sul-phonate were consistent with the operation of a glycollate pathway of the type found in the leaves of higher plants. In addition, several enzymes associated with gly-collate metabolism in other photosynthetic organisms were demonstrated in cell-free extracts of E. gracilis grown with glycollate as the only carbon source. These included glycollate oxidase, NADPH: glyoxylate reductase, NADH: glyoxylate reductase (E.C.1.1.1.26), glycine transaminase (E.C.2.6.1.4), formyltetrahydro-folate synthetase (E.C. 6.3.4.3), and serine hydroxymethyltransferase (E.C. 2.1.2.1).

scholarly journals Occurrence and operation of the glycollate–glyoxylate shuttle in mitochondria of Euglena gracilis Z

1979 ◽  
Vol 184 (1) ◽  
pp. 189-192 ◽  
Author(s):  
A Yokota ◽  
S Kitaoka
Keyword(s):  
Euglena Gracilis ◽  
Higher Plants ◽  
Glycollate Dehydrogenase ◽  
Actual Operation ◽  
Nadph Oxidation ◽  
Euglena Gracilis Z ◽  
Glyoxylate Reductase

Both glyoxylate reductase (NADP+) and glycollate dehydrogenase were located exclusively in mitochondria in Euglena gracilis and constitute the glycollate–glyoxylate shuttle, whose existence in higher plants was thought doubtful, owing to different subcellular locations of the two enzymes. Disrupted Euglena mitochondria showed a glycollate-dependent NADPH oxidation, indicating actual operation of the shuttle in this protozoon.

Circadian Synthesis of Light-Harvesting-Chlorophyll-Proteins in Euglena gracilis Is under Translational Control

1998 ◽  
Vol 53 (11-12) ◽  
pp. 1017-1026 ◽  
Author(s):  
A. Kiinne ◽  
E. Pistorius ◽  
K. Kloppstech ◽  
E. de Groot
Keyword(s):  
Euglena Gracilis ◽  
Translational Control ◽  
Light Harvesting ◽  
Higher Plants ◽  
Mrna Levels ◽  
Stationary Concentration ◽  
The Family ◽  
Molecular Masses ◽  
Lhcp Ii ◽  
Translational Level

Abstract Two proteins with apparent molecular masses of 17 and 24 kD that are synthesized in a circadian manner in the phytoflagellate Euglena gracilis, were recognized as proteins belong­ing to the family of light-harvesting-chlorophyll-proteins (LHCPs) of class I (17 kD) and of class II (24 kD). Identification was achieved by N-terminal sequencing of the proteins isolated from two-dimensional polyacrylamide gels and by detection with an anti-LHCP II se­rum. While it was found that the total amount of LHCPs remains almost constant, when Euglena is grown under diurnal conditions (12 h light and 12 h dark), we could show that the amount of newly synthesized 17 and 24 kD proteins varies about 20-fold with a maximum of synthesis in the light phase. In contrast, the analysis of the mRNA levels at different times revealed only minor differences in the stationary concentration of the LHCP specific mRNA, indicating that the control of LHCP synthesis is at the translational level. Principally, the same finding was obtained using inhibitors of transcription. Thus, it is concluded that the expression of LHCPs in Euglena gracilis in contrast to that of higher plants is primarily regulated at the translational level.

Inhibition by isonicotinyl hydrazide of pigment formation in higher plants

1974 ◽  
Vol 13 (9) ◽  
pp. 1657-1665 ◽  
Author(s):  
Michael G. Gore ◽  
Howard M. Hill ◽  
Brian Evans ◽  
Lyndon J. Rogers
Keyword(s):  
Higher Plants ◽  
Pigment Formation ◽  
Isonicotinyl Hydrazide

DNA microarrays for studies of higher plants and other photosynthetic organisms

1999 ◽  
Vol 4 (1) ◽  
pp. 38-41 ◽  
Author(s):  
David M. Kehoe ◽  
Per Villand ◽  
Shauna Somerville
Keyword(s):  
Dna Microarrays ◽  
Higher Plants ◽  
Photosynthetic Organisms

scholarly journals Mucoromycotina Fungi Possess the Ability to Utilize Plant Sucrose as a Carbon Source: Evidence From Gongronella sp. w5

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiaojie Wang ◽  
Junnan Fang ◽  
Pu Liu ◽  
Juanjuan Liu ◽  
Wei Fang ◽  
...  
Keyword(s):  
Carbon Source ◽  
Host Plant ◽  
Specific Activity ◽  
Higher Plants ◽  
Transcriptional Level ◽  
Post Inoculation ◽  
Phylogenetic Tree Analysis ◽  
Root Cells ◽  
Carbon Supply

Mucoromycotina is one of the earliest fungi to establish a mutualistic relationship with plants in the ancient land. However, the detailed information on their carbon supply from the host plants is largely unknown. In this research, a free-living Mucoromycotina called Gongronella sp. w5 (w5) was employed to explore its effect on Medicago truncatula growth and carbon source utilization from its host plant during the interaction process. W5 promoted M. truncatula growth and caused the sucrose accumulation in M. truncatula root tissue at 16 days post-inoculation (dpi). The transportation of photosynthetic product sucrose to the rhizosphere by M. truncatula root cells seemed accelerated by upregulating the SWEET gene. A predicted cytoplasmic invertase (GspInv) gene and a sucrose transporter (GspSUT1) homology gene in the w5 genome upregulated significantly at the transcriptional level during w5–M. truncatula interaction at 16 dpi, indicating the possibility of utilizing plant sucrose directly by w5 as the carbon source. Further investigation showed that the purified GspInv displayed an optimal pH of 5.0 and a specific activity of 3380 ± 26 U/mg toward sucrose. The heterologous expression of GspInv and GspSUT1 in Saccharomyces cerevisiae confirmed the function of GspInv as invertase and GspSUT1 as sugar transporter with high affinity to sucrose in vivo. Phylogenetic tree analysis showed that the ability of Mucoromycotina to utilize sucrose from its host plant underwent a process of “loss and gain.” These results demonstrated the capacity of Mucoromycotina to interact with extant land higher plants and may employ a novel strategy of directly up-taking and assimilating sucrose from the host plant during the interaction.

scholarly journals Über den Katabolismus von Hamamelose [2-C(Hydroxymethyl)-ᴰ-ribose] / On the Catabolism of Hamamelose [2-C-(hydroxymethyl)-ᴰ-ribose]

1971 ◽  
Vol 26 (9) ◽  
pp. 912-915 ◽  
Author(s):  
A. Thanbichler ◽  
H. Gilck ◽  
E. Beck
Keyword(s):  
Carbon Source ◽  
Phosphate Buffer ◽  
Higher Plants ◽  
Sugar Alcohol ◽  
Radioactive Product ◽  
Branched Chain ◽  
Almost All ◽  
Additional Carbon Source

Free hamamelose [2-C- (hydroxymethyl) -ᴰ-ribose] occurs in almost all higher plants, but except a reduction to the corresponding sugar alcohol (hamamelitol) , no metabolism of this branched chain hexose could be detected in plants until now. Therefore we tried to find microorganisms which would allow us to study the catabolism of hamamelose. A strain of Pseudomonas (“H 1”), showing dependence between growth and hamamelose concentration in the medium (Fig. 1), was isolated from soil on which Primula clusiana was grown (this plant contains large amounts of hamamelose and hamamelitol). However, this organism needs citrate besides hamamelose for growth.When “H 1” was incubated in a phosphate buffer containing only 14C-labelled hamamelose, hamamelonic acid was the sole radioactive product formed (Tables 2, 3, 4).As no further degradation of hamamelonic acid by “H 1” could be detected, we conclude that this organism uses hamamelose as a hydrogen source only. Thus it becomes reasonable that “H 1” needs an additional carbon source (citrate) for growth.

scholarly journals A unique ferredoxin acts as a player in the low-iron response of photosynthetic organisms

2018 ◽  
Vol 115 (51) ◽  
pp. E12111-E12120 ◽  
Author(s):  
Michael Schorsch ◽  
Manuela Kramer ◽  
Tatjana Goss ◽  
Marion Eisenhut ◽  
Nigel Robinson ◽  
...  
Keyword(s):  
Protein Function ◽  
Posttranscriptional Regulation ◽  
Iron Homeostasis ◽  
Higher Plants ◽  
Iron Status ◽  
Photosynthetic Electron Transport ◽  
Protein Levels ◽  
Photosynthetic Organisms ◽  
Chlorophyll Accumulation ◽  
Iron Concentrations

Iron chronically limits aquatic photosynthesis, especially in marine environments, and the correct perception and maintenance of iron homeostasis in photosynthetic bacteria, including cyanobacteria, is therefore of global significance. Multiple adaptive mechanisms, responsive promoters, and posttranscriptional regulators have been identified, which allow cyanobacteria to respond to changing iron concentrations. However, many factors remain unclear, in particular, how iron status is perceived within the cell. Here we describe a cyanobacterial ferredoxin (Fed2), with a unique C-terminal extension, that acts as a player in iron perception. Fed2 homologs are highly conserved in photosynthetic organisms from cyanobacteria to higher plants, and, although they belong to the plant type ferredoxin family of [2Fe-2S] photosynthetic electron carriers, they are not involved in photosynthetic electron transport. As deletion offed2appears lethal, we developed a C-terminal truncation system to attenuate protein function. Disturbed Fed2 function resulted in decreased chlorophyll accumulation, and this was exaggerated in iron-depleted medium, where different truncations led to either exaggerated or weaker responses to low iron. Despite this, iron concentrations remained the same, or were elevated in all truncation mutants. Further analysis established that, when Fed2 function was perturbed, the classical iron limitation marker IsiA failed to accumulate at transcript and protein levels. By contrast, abundance of IsiB, which shares an operon withisiA, was unaffected by loss of Fed2 function, pinpointing the site of Fed2 action in iron perception to the level of posttranscriptional regulation.

Why don't plants have diabetes? Systems for scavenging reactive carbonyls in photosynthetic organisms

2014 ◽  
Vol 42 (2) ◽  
pp. 543-547 ◽  
Author(s):  
Ginga Shimakawa ◽  
Mayumi Suzuki ◽  
Eriko Yamamoto ◽  
Ryota Saito ◽  
Tatsuya Iwamoto ◽  
...  
Keyword(s):  
Photosynthetic Activity ◽  
Higher Plants ◽  
Sugar Metabolism ◽  
Toxic Effects ◽  
Medium Chain ◽  
Photosynthetic Organisms

In the present paper, we review the toxicity of sugar- and lipid-derived RCs (reactive carbonyls) and the RC-scavenging systems observed in photosynthetic organisms. Similar to heterotrophs, photosynthetic organisms are exposed to the danger of RCs produced in sugar metabolism during both respiration and photosynthesis. RCs such as methylglyoxal and acrolein have toxic effects on the photosynthetic activity of higher plants and cyanobacteria. These toxic effects are assumed to occur uniquely in photosynthetic organisms, suggesting that RC-scavenging systems are essential for their survival. The aldo–keto reductase and the glyoxalase systems mainly scavenge sugar-derived RCs in higher plants and cyanobacteria. 2-Alkenal reductase and alkenal/alkenone reductase catalyse the reduction of lipid-derived RCs in higher plants. In cyanobacteria, medium-chain dehydrogenases/reductases are the main scavengers of lipid-derived RCs.

scholarly journals Exploration of Autophagy Families in Legumes and Dissection of the ATG18 Family with a Special Focus on Phaseolus vulgaris

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2619
Author(s):  
Elsa-Herminia Quezada-Rodríguez ◽  
Homero Gómez-Velasco ◽  
Manoj-Kumar Arthikala ◽  
Miguel Lara ◽  
Antonio Hernández-López ◽  
...  
Keyword(s):  
Phaseolus Vulgaris ◽  
Higher Plants ◽  
Large Family ◽  
Lipid Binding ◽  
Model Organisms ◽  
Special Focus ◽  
Scaling Analysis ◽  
Protein Motifs ◽  
Photosynthetic Organisms ◽  
Atg Genes

Macroautophagy/autophagy is a fundamental catabolic pathway that maintains cellular homeostasis in eukaryotic cells by forming double-membrane-bound vesicles named autophagosomes. The autophagy family genes remain largely unexplored except in some model organisms. Legumes are a large family of economically important crops, and knowledge of their important cellular processes is essential. Here, to first address the knowledge gaps, we identified 17 ATG families in Phaseolus vulgaris, Medicago truncatula and Glycine max based on Arabidopsis sequences and elucidated their phylogenetic relationships. Second, we dissected ATG18 in subfamilies from early plant lineages, chlorophytes to higher plants, legumes, which included a total of 27 photosynthetic organisms. Third, we focused on the ATG18 family in P. vulgaris to understand the protein structure and developed a 3D model for PvATG18b. Our results identified ATG homologs in the chosen legumes and differential expression data revealed the nitrate-responsive nature of ATG genes. A multidimensional scaling analysis of 280 protein sequences from 27 photosynthetic organisms classified ATG18 homologs into three subfamilies that were not based on the BCAS3 domain alone. The domain structure, protein motifs (FRRG) and the stable folding conformation structure of PvATG18b revealing the possible lipid-binding sites and transmembrane helices led us to propose PvATG18b as the functional homolog of AtATG18b. The findings of this study contribute to an in-depth understanding of the autophagy process in legumes and improve our knowledge of ATG18 subfamilies.

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