Pyruvate metabolism in germinating seeds during natural anaerobiosis

Leblová, Sylva; Sinecká, Eva; Vaníčková, Věra

doi:10.1007/bf02922229

Cited by 28 publications

(16 citation statements)

References 19 publications

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“…The amount of lactate detected at the end of the aerobic imbibition period was low in all species, except pea. Ethanol was found in large amounts in pea, maize, and soya, and in lower amounts in wheat, sunflower, and radish (Table II): these amounts represent the balance of ethanol production and losses by evaporation; in agreement with previous results (15) we observed that the ethanol content ofthe seeds was increased under conditions, such as excess water, which limit the gaseous exchanges, either O2 input or ethanol evaporation.…”

Section: Resultssupporting

confidence: 91%

“…From many old results and from her own data, Leblova (15) asserted that, during the initial phases of germination, seeds are under natural anaerobiosis. It should be noticed that most published studies concerning fermentative and respiratory metabolism in seeds were carried out with seeds of legumes.…”

Section: Discussionmentioning

confidence: 99%

“…Even under well-aerated conditions, ethanol and lactate accumulation may occur. It is generally considered that, during the first hours of imbibition, seeds are under 'natural anaerobiosis' (15). However, oxidative phosphorylation was demonstrated in mitochondria of the freshly imbibed Arachis hypogea axis (28), and, using an in vivo method, in lettuce seeds after 15 min of imbibition (12).…”

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confidence: 99%

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ATP Production by Respiration and Fermentation, and Energy Charge during Aerobiosis and Anaerobiosis in Twelve Fatty and Starchy Germinating Seeds

Raymond¹,

Alani²,

Pradet³

1985

Plant Physiol.

112

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The respiration and fermentation rates were compared in germinating seeds of 12 different cultivated species from five families. In air, fermentation contributes significantly to the energy metabolism only in some species (pea, maize), but is generally negligible when compared to respiration. The fermentation rate under anoxia was related either to the metabolic activity under air or to the adenine nucleotide content of the seeds: it was generally higher in seeds which contain starchy reserves (rice, maize, sorghum, pea), than in seeds which do not contain starch (lettuce, sunflower, radish, turnip, cabbage, flax); however, it was similar in wheat, sorghum (starchy seeds), and soya (nonstarchy seeds). The value of the energy charge of all the seeds was lower under anoxia than in air: after 24 hours under anoxia, it was higher than 0.5 in the starchy seeds and in soya and it was around 0.25 in the other fatty seeds.anaerobiosis in seed germination.The present work is part of a study in which we used a comparative, physiological approach with seeds of 12 different species belonging to five families. When studying the effect of the P02 on the rate of germination (2), we found that the seeds could be classed in two groups: group I included fatty seeds; in these seeds, radicle emergence did not occur below I kPa 02. Group II included starchy species, which were able to germinate at 02 partial pressures below 0.1 kPa. In the present work, the rate of 02 uptake, the rate of ethanol and lactate synthesis, and the value of AdN ratios (ATP/ADP or AEC), were used as indicators of ATP regeneration.We found that, in aerated conditions, respiration was the dominating ATP-regenerating pathway in all seeds, whereas fermentation contributed significantly only in some species. Starchy seeds appeared to maintain a higher energy metabolism under anoxia than the fatty seeds, although the two groups overlap to some extent.When dry seeds are imbibed, the respiratory activity, characterized by 02 uptake and CO2 evolution, starts extremely rapidly (5). For a long time, it was thought that this oxidative process was not coupled to ATP production and some original mechanisms were recently proposed (17) to explain the origin of the ATP needed for the biosynthetic work done during germination. Even under well-aerated conditions, ethanol and lactate accumulation may occur. It is generally considered that, during the first hours of imbibition, seeds are under 'natural anaerobiosis' (15). However, oxidative phosphorylation was demonstrated in mitochondria of the freshly imbibed Arachis hypogea axis (28), and, using an in vivo method, in lettuce seeds after 15 min of imbibition (12). Hence, the respiration of seeds is probably an important source ofATP during the initial phases ofgermination (19).In a recent study, we found that the fermentative pathways contributed very little to ATP regeneration in germinating lettuce seeds (21). Moreover, their respiratory activity is saturated by PO2' below that of air (2,22). Such characteristics a...

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Section: Resultssupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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ATP Production by Respiration and Fermentation, and Energy Charge during Aerobiosis and Anaerobiosis in Twelve Fatty and Starchy Germinating Seeds

Raymond¹,

Alani²,

Pradet³

1985

Plant Physiol.

112

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“…Rough reticulum saccules which accumulate temporarily in pea, at the beginning of germination, are attributed to a transient anoxia (Perner 1966) as sets up in some seeds (Leblova et al 1974). Under the influence of several external factors, the plant ergastoplasm displays a dynamic behaviour.…”

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confidence: 99%

Effects of energetic shortage upon the ultrastructure o f some organelles, in excised roots of Lycopersicum esculentum cultivated in vitro. I. Reversible structural modifications of the endoplasmic reticulum.

Morisset

1983

CYTOLOGIA

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“…3) (Monning, 1983;Kubo et al, 1990). Além do mais, como já foi indicado por Ke et al (1995), quando o transporte de elétrons e a oxidação fosforilativa estão sendo inibidos, a única fonte de produção de energia para a manutenção dos tecidos é por fosforilação de substrato na via glicolítica, sendo que esta rota depende da disponibilização de potencial de redução via rota fermentativa (Leblova, 1978). O continuado incremento na produção de etanol, acompanhado pelo decréscimo na atividade respiratória de mangas dos tratamentos com 50% e 70% de CO 2 após a transferência para ar a 20°C, pode ser decorrência de dano irreversível na estrutura dos mitocôndrios, em conseqüência da prolongada exposição a extremas concentrações de CO 2 .…”

Section: Resultsunclassified

Respiração e produção de etanol e de etileno em mangas armazenadas sob diferentes concentrações de dióxido de carbono e oxigênio

Bender

Brecht

2000

Pesq. agropec. bras.

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RESUMO -O objetivo deste trabalho foi avaliar a respiração e produção de etanol e etileno em mangas armazenadas sob reduzidas concentrações de oxigênio (O 2 ) e elevadas concentrações de dióxido de carbono (CO 2 ). Mangas pré-climatéricas das cultivares Kent e Tommy Atkins foram armazenadas, sob fluxo contínuo, por 14 ou 21 dias, a 12°C em três concentrações de O 2 : 3%, 5% ou 21% em mistura com concentrações de 5%, 15%, 25%, 35%, 45%, 50% ou 70% de CO 2 . O tratamento-testemunha constou de armazenagem em ar sob fluxo contínuo. Após o período em atmosfera controlada (AC), as mangas foram transferidas e mantidas por 5 dias em ar a 20 o C. Mangas sob concentrações de 50% e 70% de CO 2 produziram mais etanol que nas demais concentrações de CO 2 . A redução para 3% de O 2 na atmosfera de armazenagem aparentemente não teve efeito adicional ao CO 2 na produção de etanol. A atividade respiratória de mangas em AC com CO 2 acima de 45% foi muito mais intensa do que a respiração sob as concentrações de CO 2 mais baixas; a produção de etileno, no entanto, esteve suprimida, e, mesmo após a transferência para ar, não se recuperou, permanecendo inferior aos demais tratamentos. A queda na atividade respiratória das mangas armazenadas a 50% e 70% de CO 2 , quando foram transferidas para ar a 20 o C indica que as elevadas concentrações de CO 2 causaram dano irreparável aos tecidos.Termos para indexação: Mangifera indica, cultivar Kent, cultivar Tommy Atkins, armazenagem em atmosfera controlada, anaerobiose. RESPIRATION RATES AND ETHANOL AND ETHYLENE PRODUCTION OF MANGOES STORED UNDER ELEVATED CARBON DIOXIDE AND REDUCED OXIGEN ATMOSPHERESABSTRACT -The objective of this work was to evaluate respiration rates and ethanol and ethylene production of mangoes stored in controlled atmosphere (CA) with reduced O 2 and elevated CO 2 concentrations. Pre-climacteric Kent and Tommy Atkins mangoes were stored for 14 or 21 days at 12°C in 5%, 15%, 25%, 35%, 45%, 50% or 70% CO 2 plus either 21%, 5% or 3% O 2 in a flow through CA system at 12°C. In the control treatment fruits were stored in air at the same temperature and also in the flow through system. After the CA storage the mangoes were transferred and kept for 5 days in air at 20 o C. Mangoes stored in either 50% or 70% CO 2 had the highest ethanol production rates. The reduction to 3% of the O 2 concentration in the storage atmosphere does not seem to have an additional effect on ethanol production. Respiratory rates of mangoes in CA above 45% CO 2 atmospheres were higher than in the other treatments, while ethylene production rates were the lowest values. After transfer to air at 20 o C, respiration rates of mangoes from these treatments dropped significantly below control levels, which, associated with lower rates of ethylene production, indicate that the mangoes had been damaged by the elevated CO 2 atmospheres.

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Pyruvate metabolism in germinating seeds during natural anaerobiosis

Cited by 28 publications

References 19 publications

ATP Production by Respiration and Fermentation, and Energy Charge during Aerobiosis and Anaerobiosis in Twelve Fatty and Starchy Germinating Seeds

ATP Production by Respiration and Fermentation, and Energy Charge during Aerobiosis and Anaerobiosis in Twelve Fatty and Starchy Germinating Seeds

Effects of energetic shortage upon the ultrastructure o f some organelles, in excised roots of Lycopersicum esculentum cultivated in vitro. I. Reversible structural modifications of the endoplasmic reticulum.

Respiração e produção de etanol e de etileno em mangas armazenadas sob diferentes concentrações de dióxido de carbono e oxigênio

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