Activities of the cyanide-resistant respiratory pathway in leaves of sun and shade species

2001 ◽  
Vol 28 (1) ◽  
pp. 27 ◽  
Author(s):  
Ko Noguchi ◽  
Chun-Sim Go ◽  
Ichiro Terashima ◽  
Shingo Ueda ◽  
Tadashi Yoshinari
Keyword(s):  
Spinacia Oleracea ◽  
Proton Translocation ◽  
Plant Mitochondria ◽  
Oxygen Electrode ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Respiratory Pathway ◽  
Higher Plant ◽  
Atp Production ◽  
Spinacia Oleracea L

Higher plant mitochondria have a cyanide-resistant alternative respiratory pathway of electron transport (AP) that is not coupled to proton translocation. To characterise the ecophysiology of this apparently ‘wasteful’ pathway, we constructed a system consisting of a gas-phase oxygen electrode and an air sampling line for measurement of stable oxygen isotope ratios. With this system, we were able to measure respiratory rates of a small amount of leaf segments of ca 0.6 g fresh weight, and collect about 100 L of the air from the oxygen electrode chamber several times. The 18 O/16 O ratio in the air samples was measured by mass spectrometry. The activity of AP was estimated based on the isotopic discrimination of 18 O. We used the leaves of Alocasia odora (Lodd.) Spach., a shade species, and Spinacia oleracea L. and Phaseolus vulgaris L., sun species. These plants were grown at two levels of photosynthetically active photon flux density (PPFD). Three main findings were: (1) in the leaves of A. odora, the contribution of AP was less than 10% of the total respiratory rate, irrespective of growth PPFD; (2) for the sun species grown at high PPFD, the contribution of AP in the leaves was about 40% early in the night, but decreased dramatically late in the night; and (3) when S. oleracea was grown at low PPFD, the contribution of AP in the leaves declined. The low activity of AP in the leaves of A. odora suggests that the efficiency of adenosine triphosphate (ATP) production (ATP/O 2 ) of this species is high. This may be especially important in shaded environments where input of light energy is low. We also suggest that, in the leaves of sun species, ATP/O 2 changes depending on the conditions.

Rate Limitation of Non-Steady-State Photosynthesis by Ribulose-1,5-Bisphosphate Carboxylase in Spinach

1989 ◽  
Vol 16 (6) ◽  
pp. 487 ◽  
Author(s):  
IE Woodrow ◽  
KA Mott
Keyword(s):  
Relaxation Time ◽  
Steady State ◽  
Spinacia Oleracea ◽  
Exponential Phase ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Mathematical Framework ◽  
Bisphosphate Carboxylase ◽  
Quantitative Expression ◽  
Spinacia Oleracea L

A mathematical framework was developed to analyse rate limitation of non-steady-state photosynthesis following an increase in photon flux density (PFD). This analysis was employed to resolve an exponential phase of the photosynthetic response of Spinacia oleracea L. to a step increase from darkness to moderate PFD. This phase had a relaxation time of approximately 5 min, similar to the relaxation time for the activation of ribulose-1,5-bisphosphate carboxylase (Rubisco) as determined by freeze-clamp experiments following the same change in PFD. Furthermore, as the time in darkness prior to illumination was increased, the exponential phase contributed more to the overall trajectory of photosynthesis following the increase in light. The relaxation time for the increase in the contribution of this phase was 24 min. Freeze-clamp studies showed a relaxation time of 28 min for Rubisco deactivation in the dark. These results, together with measurements of RuP2 levels, suggest that the exponential phase resolved from gas exchange experiments was limited by activation of Rubisco and that Rubisco deactivation in the dark was the reason that this phase contributed more to the overall photosynthetic trajectory as time in darkness increased. A quantitative expression for the amount of extra photosynthesis that could have been obtained had Rubisco activated instantly following an increase in PFD was derived and discussed in relation to optimal functioning of the system under different environmental conditions.

scholarly journals Bolting and Growth of Spinacia oleracea L. Can be Altered by Modifying the Photoperiod during Transplant Production

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 624-626 ◽  
Author(s):  
Changhoo Chun ◽  
Ayumi Watanabe ◽  
Toyoki Kozai ◽  
Hyeon-Hye Kim ◽  
Junya Fuse
Keyword(s):  
High Temperature ◽  
Spinacia Oleracea ◽  
Market Value ◽  
Photon Flux ◽  
Artificial Light ◽  
Photosynthetic Photon Flux ◽  
Flower Stalk ◽  
Spinacia Oleracea L ◽  
Critical Photoperiod ◽  
Long Photoperiod

Spinach (Spinacia oleracea L. cv. Dimple) was chosen to determine whether bolting (i.e., elongation of flower stalks) could be controlled by manipulating the photoperiod during transplant production in a closed system using artificial light. Plants grown under various photoperiods during transplant production were transferred and cultured under natural short photoperiods and artificial long photoperiods. Vegetative growth at transplanting tended to be greater with the longer photoperiod because of the increased integrated photosynthetic photon flux. Bolting initiation reacted qualitatively to a long photoperiod, and the critical photoperiod for bolting initiation was longer than 13 h and shorter than 15 h. The plants grown under a longer photoperiod during transplant production had longer flower stalks at harvest. The long photoperiod and/or high temperature after transplanting therefore promoted flower stalk elongation. Growing plants under a photoperiod that was shorter than the critical photoperiod during transplant production reduced elongation of the flower stalks, thus there was no loss of market value even though the plants were cultured under a long photoperiod and high temperature for 2 weeks after transplanting.

The effect of light:dark cycles of medium frequency on photosynthesis by Chlorella vulgaris and the implications for waste stabilisation pond design and performance

2003 ◽  
Vol 48 (2) ◽  
pp. 69-74 ◽  
Author(s):  
I.A.J. Ratchford ◽  
H.J. Fallowfield
Keyword(s):  
Oxygen Evolution ◽  
Chlorella Vulgaris ◽  
Oxygen Electrode ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Dark Cycle ◽  
Cycle Times ◽  
Total Light ◽  
And Performance ◽  
Effect Of Light

The effect of light/dark (L:D) cycle times on the recovery from photoinhibition of green micro-alga Chlorella vulgaris (CCAP211/11c) and the cyanobacterium Synechococcus (CCAP1479/5) was investigated using an irradiated, temperature controlled oxygen electrode. The onset of photoinhibition in both organisms occurred at irradiances > 300 mmol m-2s-1 at temperatures >15°C. Light/dark cycle times were controlled independently using a relay timer and shutter placed between the quartz iodide light source and the oxygen electrode chamber. Oxygen evolution decreased rapidly when cells were continuously irradiated at 300, 500 and 750 mmol m-2s-1. However, Chlorella cells irradiated at 300, 500 and 750 mmol m-2s-1 on a L:D cycle of 60s:20s, 30s:60s and 60s:120s respectively, maintained a constant rate of oxygen evolution over a 24 h incubation period. Exposure time to a given incident irradiance rather than the total light dose received appeared to determine the effect of light/dark cycle times on photosynthesis. A relationship was established between L:D ratio required to maintain constant oxygen production and incident photon flux density. The results suggest that the adverse effects of high irradiances on algae near the surface of a stratified waste stabilisation pond might be ameliorated by controlled mixing of algal cells through the depth of the pond.

scholarly journals Influence of Green Light Added with Red and Blue LEDs on the Growth, Leaf Microstructure and Quality of Spinach (Spinacia oleracea L.)

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1724
Author(s):  
Thi-Phuong-Dung Nguyen ◽  
Dong-Cheol Jang ◽  
Thi-Thanh-Huyen Tran ◽  
Quang-Thach Nguyen ◽  
Il-Seop Kim ◽  
...  
Keyword(s):  
Organic Acid ◽  
Acid Content ◽  
Spinacia Oleracea ◽  
Growth Parameters ◽  
Green Light ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Spinach Plant ◽  
Organic Acid Content

The aim of this study was to investigate the effects of green light, added with red and blue LEDs, on the growth, leaf microstructure and quality of spinach plants. Plants were transplanted and grown hydroponically for 30 days under different combinations of red:blue with a 4:1 ratio (R4B1), red:blue:green with a 5:2:3 ratio (R5B2G3) and red:blue:green with a 1:1:1 ratio (R1B1G1), at a 190 µmoL m−2·s−1 photosynthetic photon flux density (PPFD). The results showed that green light, added to red and blue LEDs at a reasonable ratio, could reduce the growth, leaf microstructure and quality of spinach plants, but not the organic acid content. The highest values for the growth parameters, photosynthetic pigments, leaf structure characteristics and quality of the spinach plant were observed for the R4B1 treatment, but not for the organic acid content. Therefore, our results suggest that green light added to red and blue LEDs at a reasonable ratio is not suitable for the growth of spinach.

scholarly journals Anisohydric sugar beet rapidly responds to light to optimize leaf water use efficiency utilizing numerous small stomata

AoB Plants ◽  
2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Georgina E Barratt ◽  
Debbie L Sparkes ◽  
Lorna McAusland ◽  
Erik H Murchie
Keyword(s):  
Sugar Beet ◽  
Soil Water ◽  
Water Availability ◽  
Spinacia Oleracea ◽  
Stomatal Density ◽  
High Rate ◽  
Soil Water Availability ◽  
Photon Flux ◽  
Photon Flux Density ◽  
High Soil

Abstract Under conditions of high transpiration and low soil water availability, the demand for water can exceed supply causing a reduction in water potential and a loss of cell turgor (wilting). Regulation of stomatal aperture mediates the loss of water vapour (gs), which in turn is dependent in part on the anatomical characteristics of stomatal density (SD) and stomatal size (SS). Anisohydric sugar beet (Beta vulgaris) is atypical, exhibiting wilting under high soil water availability. Spinach (Spinacia oleracea) belongs to the same family Chenopodiaceae s.s., but demonstrates a more typical wilting response. To investigate the role of stomatal dynamics in such behaviours, sugar beet and spinach leaves were exposed to step-changes in photosynthetic photon flux density (PPFD) from 250 to 2500 µmol m−2 s−1. Using a four log-logistic function, the maximum rate of stomatal opening was estimated. Concurrent measurements of SD and SS were taken for both species. While sugar beet coupled faster opening with smaller, more numerous stomata, spinach showed the converse. After exposure to drought, maximum gs was reduced in sugar beet but still achieved a similar speed of opening. It is concluded that sugar beet stomata respond rapidly to changes in PPFD with a high rate and magnitude of opening under both non-droughted and droughted conditions. Such a response may contribute to wilting, even under high soil water availability, but enables photosynthesis to be better coupled with increasing PPFD.

scholarly journals Effect of blue, green or red LED light on the functional quality of spinach (Spinacia oleracea L.)

2021 ◽  
Vol 53 (1) ◽  
pp. 98-108
Author(s):  
Benjamín Battistoni ◽  
Asunción Amorós ◽  
María Luisa Tapia ◽  
Víctor Hugo Escalona
Keyword(s):  
Antioxidant Capacity ◽  
Phenolic Compound ◽  
Spinacia Oleracea ◽  
Photon Flux ◽  
Total Phenolic ◽  
Led Light ◽  
Spinacia Oleracea L ◽  
Red Led ◽  
Led Lights ◽  
Compound Concentration

The present study employed white (W), blue (B: 468 nm), red (R: 629 nm) and green (G: 524 nm) monochromatic LED lights for 26 days, from 11:00 to 18:00 (7 h per day), with a average of photosynthetic photon flux density (PPFD) of 26.00 m-2 s-1 on two baby leaves of spinach (Spinacia oleracea L.) cultivars (Falcon F1 and Viroflay) grown in a hydroponic system. Regardless of the cultivar, the fresh and dry weights were positively influenced when the plants were irradiated by R-light in comparison to W-light. Independent of the cultivar, the leaves treated with B-light reached a significantly higher phenolic compound concentration than plants irradiated with W-light. With respect to antioxidant capacity, plants treated with B-light showed a significantly higher antioxidant capacity than those treated with W-light. According to the results, the use of LED lights is a promising technique for the production of antioxidant compound-enriched vegetables. Highlights - The fresh and dry weights were positively influenced when baby leaves spinach were irradiated by red LED light. - Baby leaves spinach treated with blue LED light reached a significantly higher phenolic compound concentration and antioxidant capacity. - The green LED light increased total phenolic compound concentration in baby leaves spinach.

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