Activity of glucose-6-phosphate dehydrogenase from lettuce seeds (Lactuca sativa)

1974 ◽  
Vol 52 (10) ◽  
pp. 2225-2227 ◽  
Author(s):  
Henry L. Speer
Keyword(s):  
Enzyme Activity ◽  
Lactuca Sativa ◽  
Red Light ◽  
Supernatant Fraction ◽  
Lettuce Seed ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Glucose 6 Phosphate Dehydrogenase

The effects of phosphate, arsenate, arsenite, and sulfate on lettuce seed (Lactuca sativa L.) glucose-6-phosphate dehydrogenase were investigated. All four substances inhibited the enzyme and inhibition was substrate dependent. The reaction was specific for glucose-6-phosphate and NADP. No effect of red or far-red light could be observed on enzyme activity. All enzyme activity was confined to the supernatant fraction.

scholarly journals Preventing thermoinhibition in a thermosensitive lettuce genotype by seed imbibition at low temperature

2003 ◽  
Vol 60 (3) ◽  
pp. 477-480 ◽  
Author(s):  
Warley Marcos Nascimento
Keyword(s):  
Seed Germination ◽  
Low Temperature ◽  
High Temperatures ◽  
Lactuca Sativa ◽  
Lettuce Seed ◽  
Temperature Dependent ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Lettuce Seed Germination ◽  
Dark Green

Lettuce (Lactuca sativa L.) seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB) were incubated at temperatures ranging from 15° to 35°C at light and dark conditions. Other seeds were imbibed in dark at 20°; 25°; 30°; and 35°C for 8 and 16 hours and then transferred to 20 or 35°C, in dark. Seeds were also incubated at constant temperature of 20° and 35 °C, in the dark, as control. In another treatment, seeds were primed for 3 days at 15°C with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25°C. Seeds incubated at 20°C had 97% germination, whereas seeds incubated at 35°C did not germinate. Seeds imbibed at 20°C for 8 and 16 hours had germination. At 35°C, seeds imbibed initially at 20°C for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25°C for 16 hours, germinated satisfactory at 35°C. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20°C. Primed seeds had 100% germination at 35°C, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.

The effects of ultra-high diluted gibberellic acid on in vitro lettuce seed germination.

2021 ◽  
Vol 15 (4) ◽  
pp. 50-54
Author(s):  
Carolina Santos Barreto ◽  
Fortune Homsani ◽  
Nina C Barboza Da Silva ◽  
Carla Holandino
Keyword(s):  
Gibberellic Acid ◽  
Lactuca Sativa ◽  
Germination Rate ◽  
Petri Dish ◽  
New Drugs ◽  
Lettuce Seed ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Petri Dishes

Lettuce seeds bioassays have been used in many different tests such as: alellopathyc models; developing of new drugs; ecotoxicity tests. In most cases, lettuce (Lactuca sativa L., Asteraceae) has been used because of its sensitivity, simultaneous and rapid germination, reliability of germination percentage and homogeneity of seeds. The main goal was to evaluate the effects of ultra-high diluted gibberellic acid (GA3) on lettuce seeds germination and seedling growth. Experiment was performed using Petri dishes containing one disk of Whatman nº01 paper watered with 1ml of water. In each Petri dish 10 lettuce seeds(Lactuca sativa L.) cv Regina 500 were placed and 2ml of the different treatment solutions were add: GA33µmol, GA3 3CH (10-6), GA3 12CH (10-24), water 12CH and water (no dilution and succussion). One milliliter solutions were added every 2 days of experiment. The experiment was repeated twice and each one consisted in 5 Petri dishes per treatment (n=100). All seeds were maintained in germination incubator under controlled temperature (25°C) and photoperiod (16L/8D). The tested substances were prepared according to Brazilian Homeopathic Pharmacopoeia (Brazil, 2011). The experiment was blinded all the time. All seeds germinated at same time (2 days) and after 7 days the germination rate was the same in all treatments. Root was affected just by Water 12 CH, in which shown the longest length (4.59 cm) when compared with others treatments. Shoot length was higher where gibberellin was added in concentration upper then Avogrado’s number.

Seed water content in relation to phytochrome-mediated germination of lettuce seeds (Lactuca sativa L. var. Grand Rapids)

1971 ◽  
Vol 49 (1) ◽  
pp. 111-115 ◽  
Author(s):  
A. I-Hsiung Hsiao ◽  
William Vidaver
Keyword(s):  
Water Content ◽  
Lactuca Sativa ◽  
Red Light ◽  
Second Stage ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Grand Rapids ◽  
Two Stages ◽  
Seed Water Content ◽  
Stimulation Of

It is possible to distinguish two stages in the influence of light on the germination of Lactuca sativa var. Grand Rapids (lettuce) seeds. The first stage, which is represented by the photoactivation or transformation of phytochrome, requires only a relatively low seed water content. Slightly higher seed water content is required for maximum far-red light repression, than for red light stimulation of germination. The second stage is indicated by the well-known situation in which previous red irradiations of the seeds can enhance germination but this takes place only with relatively high seed water content. Phototransformed phytochrome appears to persist and to be susceptible to photoreversal for at least 24 h after irradiation in the seeds with relatively low water content.

ACTION AND INTERACTION OF MONOCHROMATIC LIGHT ON PHOSPHATE METABOLISM OF GERMINATING LETTUCE SEEDS

1962 ◽  
Vol 40 (7) ◽  
pp. 965-974 ◽  
Author(s):  
Kenneth Surrey
Keyword(s):  
Energy Flow ◽  
Spectral Band ◽  
Red Light ◽  
Monochromatic Light ◽  
Lettuce Seed ◽  
Phosphate Metabolism ◽  
Lettuce Seeds ◽  
Phytochrome System ◽  
Lettuce Seed Germination ◽  
Partial Suppression

A previously described photoresponse of lettuce seed germination to red and far-red light is shown to be paralleled by a response of phosphate metabolic activity: (1) When seeds were continuously irradiated, red light accelerated and far-red suppressed their phosphate uptake and esterification. (2) The influence of monochromatic light on phosphate metabolism of seeds, determined after 36 and 64 hours of germination, respectively, indicated maximum potentiation between 550 and 650 mμ, maximum suppression beyond 700 mμ, and partial suppression at 475 mμ. Stimulation was encountered at 400 mμ, but with shorter wavelengths of the ultraviolet spectrum, suppression appeared again. (3) Photoactivation of phosphate metabolism in response to each of the three loci (550, 600, and 650 mμ, i.e., green, orange, and red light, respectively) of the potentiating spectral band was reversed by far-red (750 mμ) light. These activations and inhibitions could be reversed several times in an alternating sequence. Complete reversibility depended entirely upon the magnitudes of the radiant flux for the two counteracting wavelengths, and this was characteristic for each pair of antagonistic wavelengths. In view of the association of phytochrome with the isolated mitochondria and of the specific manner in which their phosphorylation activity is influenced by light, it is suggested that a part of the energy flow required for cellular development may be channeled through the mitochondrial–phytochrome system.

scholarly journals Inactivation of glucose 6-phosphate dehydrogenase during germination and outgrowth of Bacillus cereus T endospores

1975 ◽  
Vol 148 (2) ◽  
pp. 259-268 ◽  
Author(s):  
M Orlowski ◽  
M Goldman
Keyword(s):  
Enzyme Activity ◽  
Specific Activity ◽  
Proteolytic Enzymes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Total Activity ◽  
Cellular Protein ◽  
Metabolic Energy ◽  
Supernatant Fraction ◽  
Stage Of Development ◽  
Glucose 6 Phosphate Dehydrogenase

The specific activity and total activity of glucose 6-phosphate dehydrogenase (EC 1.1.1.49) under conditions of complete cell breakage fall 10-20-fold during a 3h period of spore germination and outgrowth. The spores must germinate (lose refractility), but do not have to undergo outgrowth, for the loss of activity to occur. Glucose 6-phosphate dehydrogenase activity from cells as any stage of development is completely stable in extracts at 4 degrees C or 30 degrees C. All of the enzyme activity is found in a soluble (50000g supernatant) fraction and remains completely soluble throughout development. Soluble protein and total cellular protein remain constant for about 2h. Proteinases could not be detected or protein turnover demonstrated during the morphogenetic process. Phenylmethanesuophony fluoride and o-phenanthroline, inhibitors of proteolytic enzymes, do not prevent glucose 6-phosphate dehydrogenase inactivation when added to whole cells. Mixing experiments show no inhibitor of glucose 6-phosphate dehydrogenase to be present in late-stage cells. The enzyme is not excreted into the culture medium. Chloramphenicol and rifampicine immediately stop protein synthesis and development but not the inactivation of glucose 6-phosphate dehydrogenase. NaN3, 2,4-dinitrophenol or anaerobiosis immediately stop development and prevent the loss of enzyme activity. A requirement for metabolic energy is therefore probable. Extracts of spores pre-labelled with L[14C]leucine were made at various stages of morphogenesis and subjected to polyacrylamide-gel electrophoresis. Glucose 6-phosphate dehydrogenase, which was identified by a specific stain, did not lose 14C label, and therefore may not be degraded during the inactivation process.

scholarly journals Effect of landfill leachate on germination of lettuce seeds (Lactuca sativa L.)

2017 ◽  
Vol 21 ◽  
pp. 67
Author(s):  
Heider Alves Franco ◽  
Monica Regina da Costa Marques ◽  
Clarisse Ferreira Braga ◽  
Allana De Souza Izidorio ◽  
Sérgio Thode Filho
Keyword(s):  
Lactuca Sativa ◽  
Landfill Leachate ◽  
Lettuce Seeds ◽  
Lactuca Sativa L

scholarly journals (421) Light and Temperature Interactions in Promoting Lettuce Seed Germination

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1021E-1022
Author(s):  
Samuel Contreras ◽  
David Tay ◽  
Mark Bennett
Keyword(s):  
Red Light ◽  
Light Treatment ◽  
Effect Of Temperature ◽  
Lettuce Seed ◽  
Lettuce Seeds ◽  
Radicle Emergence ◽  
Lettuce Seed Germination ◽  
Temperature Interactions ◽  
Soaking Temperature ◽  
Light Break

Lettuce seeds (Lactuca sativavar. acephalacv. Tango) were used with the objective of determining the effect of temperature, light, and their interactions in promoting germination. Under standard op-timal conditions (20 °C, light), the seed presented 100% germination (radicle emergence 5 d after sowing). Different treatments evaluated germination under dark conditions, with or without a red light break (LB, 28.8 mmol·m-2) 48 h after sowing, and with different combination of temperatures pre- (soaking temperature, ST) and post- (germination temperature, GT) the LB. Germination at constant 20 °C without LB was less than 5%, and with LB, it was around 30%. However, germination was close to 100% at GT of 20 °C when LB was applied after a ST of 10 °C, and around 50% under the same conditions, but without LB. When GT was 30 °C and LB was applied, germination was less than 3% with ST = 30 °C, less than 10% with ST = 20 °C, and around 100% when ST = 10 °C. With ST and GT of 10 °C and 30 °C, respectively, and no LB, germination was less than 5%. Germination at 10 °C constant, with and without LB, was around 90% and 0%, respectively. When ST was 40 °C and LB was applied, germination was around 40% at GT= 20 °C, but less that 3% with GT= 30 °C. In summary, a severe inhibition of germination was observed when seeds were germinated in dark, which was partially reversed by either a light treatment or soaking at 10 °C, and fully reversed when both treatments were applied together. Inhibition of lettuce germination at 30 °C was observed when this temperature was applied after a light treatment, but not when applied before. Possible implications of these results for the phytochrome mechanism of action are discussed.

scholarly journals Effect of Gibberellic Acid, Kinetin, and Ethylene plus Carbon Dioxide on the Thermodormancy of Lettuce Seed (Lactuca sativa L. cv. Mesa 659)

1975 ◽  
Vol 56 (6) ◽  
pp. 826-829 ◽  
Author(s):  
Robert D. Keys ◽  
Orrin E. Smith ◽  
Junji Kumamoto ◽  
Jessye L. Lyon
Keyword(s):  
Carbon Dioxide ◽  
Gibberellic Acid ◽  
Lactuca Sativa ◽  
Lettuce Seed ◽  
Lactuca Sativa L
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