ATP and Energy Charge as Criteria of Growth and Metabolic Activity of Mollicutes: Application to Spiroplasma citri

Saglio, Pierre H.; Daniels, Michael J.; Pradet, A.

doi:10.1099/00221287-110-1-13

Cited by 38 publications

(18 citation statements)

References 15 publications

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“…ATP, ADP, and AMP were measured using the bioluminescence method according to Pradet (18) and Saglio et al (26 (17). The gels were treated with dimethylsulfoxide and 2-5 diphenyloxazole for fluorography (6,13).…”

Section: Methodsmentioning

confidence: 99%

Effect of Anoxia on Energy Charge and Protein Synthesis in Rice Embryo

Mocquot¹,

Prat²,

Mouchès³

et al. 1981

Plant Physiol.

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Energy charge, adenine nucleotide levels, and protein synthesis were studied during the transfer of rice seedlngs from air to anoxia. Within minutes, the energy charge value dropped from 0.90 in air to 0.50 in the seed and 0.60 in the coleoptile after the transfer to a nitrogen atmosphere, and then increased to a value of 0.80 during the subsequent hours. The sum of nucleotides also dropped to 60% of the value in air in the seeds and to 30% in the coleoptiles. However, during the anaerobic growth of coleoptiles, a considerable increase in the nucleotide pool occurred.The incorporation of amino acids into proteins was measured at different stages in anoxic treatment. In rice embryo, we observed a considerable protein synthesis correlated with a high value of energy charge under anoxia. The analysis oflabeled proteins by two-dimensional polyacrylamide gel electrophoresis showed a modified pattern of polypeptides synthesized during anoxic treatment. Some of these proteins were intensively labeled and appeared to be induced by anaerobic treatment.Our data indicate that high metabolic activity occurs in rice embryo under anoxia, which can be correlated with a high energy charge value. These phenomena may be part of the mechanisms which permit the adaptation of rice embryos to anaerobiosis.In nonchlorophyllous plant tissues and in animals, it is generally assumed that ATP synthesis is drastically reduced when oxidative phosphorylation is inhibited by a lack of 02. The knowledge of the balance between ATP regeneration and utilization for metabolic work should permit a better understanding of the mechanisms used by these organisms to survive under anoxic conditions.In animal tissues, there is a rapid inhibition of protein synthesis after a few min of anoxia (10,12 Preliminary data obtained in our laboratory indicate that rice embryos or coleoptiles germinated in anoxia or transferred from air to nitrogen have a high energy charge (20, 21) and an active RNA (2) and DNA synthesis (16).The purpose of this paper is to study the effect of anoxia on adenine nucleotide levels, energy charge, and incorporation of labeled amino acids into proteins in rice embryos. The correlation between energy charge and protein synthesis in anoxia is discussed, and anoxic protein patterns sustain the hypothesis of an adaptation of rice embryo to anaerobic conditions. MATERIALS AND METHODSPlant Materials. Rice seeds (Oryza sativa L., var. Cigalon) cultivated by the Station d'Amelioration des Plantes (INRA, Montpellier, France) were mechanically husked and sterilized with commercial (NaOCl (150 g Cl/l), as described previously (16).Germination of Rice Seeds. Seeds were placed in glass flasks with water and shaken at 26 C in darkness. They remained under aerobic conditions for 40 to 48 h until coleoptiles reached 4 to 5 mm.For anoxia, samples were placed in a nitrogen flow (100 ml/ min), as previously described (16). Oxygen content was checked with an 02 analyzer (WOM, Mecanalyse, France) or by gas chromatography. PO2 in N2 was lower than...

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Section: Methodsmentioning

confidence: 99%

Effect of Anoxia on Energy Charge and Protein Synthesis in Rice Embryo

Mocquot¹,

Prat²,

Mouchès³

et al. 1981

Plant Physiol.

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“…The endonucleases and polymerases of S. citri have also been studied (6,7,47). Saglio et al (42) examined S. citri metabolism more generally by determining the energy charge values as a function of growth and metabolic activity. Only in reports of S. citri by Igwegbe and Thomas (21), who examined the arginine dihydrolase pathway, and by McElwain et al (28), who examined purine and pyrimidine metabolism, have the enzyme components of major metabolic routes been systematically studied.…”

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confidence: 99%

Metabolism of Members of the Spiroplasmataceae

Pollack

McElwain

DeSantis

et al. 1989

International Journal of Systematic Bacteriology

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Cell-free extracts from 10 strains of Spiroplasma species were examined for 67 enzyme activities of the Embden-Meyerhof-Parnas pathway, pentose phosphate shunt, tricarboxylic acid cycle, and purine and pyrimidine pathways. The spiroplasmas were fermentative, possessing enzyme activities that converted glucose 6-phosphate to pyruvate and lactate by the Embden-Meyerhof-Parnas pathway. Substrate phosphorylation was found in all strains. A modified pentose phosphate shunt was present, which was characterized by a lack of detectable glucose 6-phosphate and 6-phosphogluconate dehydrogenase activities. Spiroplasmas could synthesize purine mononucleotides by using pyrophosphate (PP,) as the orthophosphate donor. All spiroplasmas except Spiroplusmu floricolu used adenosine triphosphate (ATP) to phosphorylate deoxyguanosine; no other nucleoside could be phosphorylated with ATP by any spiroplasma tested. These results contrast with those reported for other mollicutes, in which PP, serves as the orthophosphate donor in the nucleoside kinase reaction. The participation of ATP rather than PPi in this reaction is unknown in other mollicutes regardless of the nucleoside reactant. Deoxypyrimidine enzyme activities were similar but varied in the reactions involving deamination of deoxycytidine triphosphate and deoxycytidine. All Spiroplasma spp. strains had deoxyuridine triphosphatase activity. Uridine phosphorylase activity varied among strains and is possibly group dependent. As in all other mollicutes, a tricarboxylic acid cycle is apparently absent in Spiroplasma spp. Reduced nicotinamide adenine dinucleotide oxidase activity was localized in the cytoplasmic fraction of all Spiroplusmu species tested. Our assays indicate that the members of the Spiroplasrnataceae are essentially metabolically homogeneous in the highly conserved pathways which we studied, but differ from other mollicutes in several important respects. These differences are of probable phylogenetic significance and may provide tools for recognition of higher taxonomic levels of mollicutes.The metabolism of the wall-less, helical, sterol-requiring members of the Spiroplasmataceae has been little studied. The insect and plant habitats of the spiroplasmas, as their unique phylogenetic position indicates (59), suggested to us that the metabolism of these organisms might differ from that described for other members of the class Mollicutes (10, 17,39,45,55). Identification of such metabolic differences would aid in the characterization, classification, and study of the phylogeny of the spiroplasmas. This information can also identify metabolic steps or loci that are susceptible to chemical modulations that could inhibit the spiroplasmal diseases of corn, citrus, or other plants.Most reports relating to the metabolism of spiroplasmas have concerned nutrition, noting, for example, the presence or absence of acid produced during growth with various sugars (8, 20,43,44,58). Other reports have described optimal growth responses to various additives in formulations of semi...

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“…Seeds were germinated at 25 °C and ATP was extracted from 5 embryos of seeds at different germination durations. The ATP content in the extract was measured using the bioluminescence method with a pico-ATP biophotometer, as described by Saglio et al (1979), with three replicates. The content of soluble sugar, starch, and amylase activity was tested according to the method of Huang and Chen (1985).…”

Section: Assay Of Atp Soluble Sugar Starch and Amylase Activitymentioning

confidence: 99%

Starch Mobilization in Ultradried Seed of Maize (Zea mays L.) During Germination

Wang

Jing

Lin

2005

JIPB

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The effects of ultradry storage on the starch mobilization in maize (Zea mays L.) seed after aging were investigated. The results indicated that there were no significant differences in the content of ATP, starch, and soluble sugar, as well as the activity of amylase, between ultradried seeds and seeds stored at -20 °C during germination. These results were consistent with the higher level of vigor of the ultradried seed. Sieve tube introduction of a fluorescence dye (carboxyl fluoresceindiacetate) and laser confocal microscopy were used to study the development of plasmodesmata in the ultradried seeds. The results indicated that plasmodesmata developed well in ultradried seeds. Fluorescence analysis also showed that the fluorescence intensity in the radicle of ultradried seeds was stronger than that in seeds with a higher moisture content. This suggests that ultradry treatment has no adverse effects on the seeds. After seed imbibition, cell orgaelles could be resumed. It is concluded that ultradry seed storage is beneficial for maintaining seed vigor and that starchy mobilization proceeds regularly during germination.Ultradry seed storage is a technique used to reduce the seed moisture content to less than 5%-7%, which is the lower limit traditionally considered as safe for seeds to be stored at ambient temperature. This technique can greatly reduce the cost for constructing and maintaining a seed bank and has drawn worldwide attention because of its potential economic benefit and promising application in germplasm conservation. Previous studies have indicated that the ratio of reducing sugar to non-reducing sugar decreases in ultradried seeds; the accumulation of sucrose and stachyose is essential in ultradried seeds of elm and Chinese cabbage, but no stachyose existed in ultradried seeds of maize (Wang et al. 2003). This could be one of the reasons why maize seeds are sensitive to desiccation. Ultradry seed storage could not only maintain the quality of seeds, but could also improve the storability of seeds (Zheng 1994;Zheng et al. 1998;Wang et al. 1999;Hoekstra et al. 2001).When dry, viable seeds imbibe water, a chain of events is initiated that ultimately results in the emergence of the radicle, signifying that germination has been completed successfully. On imbibition, metabolism quickly commences. Respiration, enzyme and organelle activity, and RNA and protein synthesis are fundamental cellular activities intimately involved in germination and the preparation for subsequent growth. Therefore, it is not surprising that most studies on the biochemistry of germination and growth have concentrated on these events in an attempt to elucidate the key processes that lead to the successful completion of germination. Even so, investigations of germination are scant, especially compared with those on seed

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ATP and Energy Charge as Criteria of Growth and Metabolic Activity of Mollicutes: Application to Spiroplasma citri

Cited by 38 publications

References 15 publications

Effect of Anoxia on Energy Charge and Protein Synthesis in Rice Embryo

Effect of Anoxia on Energy Charge and Protein Synthesis in Rice Embryo

Metabolism of Members of the Spiroplasmataceae

Starch Mobilization in Ultradried Seed of Maize (Zea mays L.) During Germination

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