Consequences of salt stress on conductance to CO2 diffusion, Rubisco characteristics and anatomy of spinach leaves

1998 ◽  
Vol 25 (3) ◽  
pp. 395 ◽  
Author(s):  
Sebastiano Delfine ◽  
Arturo Alvino ◽  
Massimo Zacchini ◽  
Francesco Loreto
Keyword(s):  
Salt Stress ◽  
Spinacia Oleracea ◽  
Stomatal Closure ◽  
Salt Accumulation ◽  
Bisphosphate Carboxylase ◽  
Co2 Diffusion ◽  
Spinacia Oleracea L ◽  
Mesophyll Structure ◽  
Spinach Leaves

Spinach (Spinacia oleracea L.) leaves stressed by irrigation with water containing 1% (w/v) NaCl for 20 days had low conductance to CO2 diffusion both at the stomata and in the mesophyll. Mesophyll anatomy changed in salt-stressed leaves, which could have accounted for the decreased mesophyll conductance. Ribulose- 1,5-bisphosphate carboxylase/oxygenase in vitro activity and content were not affected by up to 20 days exposure to salinity but decreased when leaves were exposed to salt stress for longer than 20 days. Salt accumulation also caused a drop of Ca and Mg which might have decreased membrane stability and chlorophyll content, respectively. Measurements of chlorophyll fluorescence indicated that the 20-day-long salt stress did not directly affect photochemistry. We conclude that salinity reduces photosynthesis primarily by reducing the diffusion of CO2 to the chloroplast, both by stomatal closure and by changes in mesophyll structure which decreases the conductance to CO2 diffusion within the leaf. The capacity for carbon metabolism is eventually reduced but that occurs after substantial decreases in the conductance to CO2 diffusion.

Characterization of Multiple Acid Phosphatases in Salt-Stressed Spinach Leaves

1987 ◽  
Vol 14 (2) ◽  
pp. 117 ◽  
Author(s):  
SM Pan
Keyword(s):  
Molecular Weight ◽  
Salt Stress ◽  
Gel Electrophoresis ◽  
Spinacia Oleracea ◽  
Acid Phosphatases ◽  
Multiple Forms ◽  
Spinacia Oleracea L ◽  
Hydroponically Grown ◽  
Spinach Leaves

Incremental salt stress brought about a clear enhancement of the activity of acid phosphatases in hydroponically grown spinach (Spinacia oleracea L.) leaves. Sephacryl S-200 chromatography of the enzyme fraction revealed multiple forms of acid phosphatases of high (300 000), intermediate (100 000), and low (35 000) molecular weight in control and salt-stressed spinach leaves. A similar zymogram of acid phosphatases, showing at least six bands in polyacrylamide disc gel electrophoresis, was observed for control and stressed leaves. However, promotive effects of incremental salt stress on the activity of acid phosphatases were more pronounced in high molecular weight acid phosphatases. Substrate specificity and differential effects of some ions on the multiple acid phosphatases were also examined for control and salt-stressed leaves.

scholarly journals Site-specific serine phosphorylation of spinach leaf sucrose-phosphate synthase

1992 ◽  
Vol 283 (3) ◽  
pp. 877-882 ◽  
Author(s):  
J L A Huber ◽  
S C Huber
Keyword(s):  
Okadaic Acid ◽  
Spinacia Oleracea ◽  
Sucrose Phosphate Synthase ◽  
Serine Phosphorylation ◽  
Spinacia Oleracea L ◽  
Spinach Leaf ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

We recently reported [Huber, Huber & Nielsen (1989) Arch. Biochem. Biophys. 270, 681-690] that spinach (Spinacia oleracea L.) sucrose-phosphate synthase (SPS; EC 2.4.1.14) was phosphorylated in vivo when leaves were fed [32P]Pi. In vitro the enzyme was phosphorylated and inactivated by using [gamma-32P]ATP. We now report that SPS is phosphorylated both in vivo and in vitro on serine residues. The protein is phosphorylated at multiple sites both in vivo and in vitro as indicated by two-dimensional peptide maps of the immunopurified SPS protein. After being fed with radiolabel, leaves were illuminated or given mannose (which activates the enzyme), in the presence or absence of okadaic acid. Feeding okadaic acid to leaves decreased the SPS activation state in the dark and light and in leaves fed mannose. Across all the treatments, the activation state of SPS in situ was inversely related to the labelling of two phosphopeptides (designated phosphopeptides 5 and 7). These two phosphopeptides are phosphorylated when SPS is inactivated in vitro with [gamma-32P]ATP, and thus are designated as regulatory (inhibitory) sites [Huber & Huber (1991) Biochim. Biophys. Acta 1091, 393-400]. Okadaic acid increased the total 32P-labelling of SPS and in particular increased labelling of the two regulatory sites, which explains the decline in activation state. In the presence of okadaic acid, two cryptic phosphorylation sites became labelled in vivo that were not apparent in the absence of the inhibitor. Overall, the results suggest that light/dark regulation of SPS activity occurs as a result of regulatory serine phosphorylation. Multiple sites are phosphorylated in vivo, but two sites in particular appear to regulate activity and dephosphorylation of these sites in vivo is sensitive to okadaic acid.

scholarly journals Effect of three organic fertilizers treatments on sensory evaluations of baby spinach (Spinacia oleracea L.)

2021 ◽  
Vol 27 ◽  
Author(s):  
C. Parwada ◽  
V. Chigiya ◽  
W. Ngezimana ◽  
J. Chipomho
Keyword(s):  
Spinacia Oleracea ◽  
Consumer Preferences ◽  
Organic Fertilizer ◽  
Organic Fertilizers ◽  
Teachers College ◽  
Spinacia Oleracea L ◽  
Sensory Evaluations ◽  
Hedonic Scale ◽  
Major Factors ◽  
Spinach Leaves

Sources of fertilizer are one of the major factors influencing baby spinach leaf texture, sweetness, bitterness and after-taste. However, the effects of fertilizer sources on baby spinach growth performance and consumer preferences are not known. A survey was carried out at the Seke Teachers’ College (SKC) community, Zimbabwe to determine the consumer preferences on the baby spinach grown on the organic fertilizer (cattle, poultry and goat manures) as well as on control inorganic  fertilizers (7% N, 14% P, 7% K). The study used 32 females and 30 males as panellists for sensory evaluations. Organoleptic tests were performed for the baby spinach leaves using a panel of 62 testers. An interval line scale (16 cm long) was used to measure the liking for sweetness, colour, bitterness and after-taste. A 9-point hedonic scale was used to decide the overall preferences. Organoleptic tests showed significant differences (P<0.05) in appearance and taste between the inorganic and organic fertilizers used. The baby spinach leaves grown on organic fertilizers was preferred more compared to that grown on inorganic fertilizer (control). Therefore, it is recommended to use organic fertilizers in baby spinach production in order to satisfy consumer preferences.

scholarly journals Synthesis and Spectrum of Biological Activities of Novel N-arylcinnamamides

2018 ◽  
Vol 19 (8) ◽  
pp. 2318 ◽  
Author(s):  
Sarka Pospisilova ◽  
Jiri Kos ◽  
Hana Michnova ◽  
Iva Kapustikova ◽  
Tomas Strharsky ◽  
...  
Keyword(s):  
Spinacia Oleracea ◽  
Biological Activities ◽  
Cell Metabolism ◽  
Photosynthetic Electron Transport ◽  
Lethal Effect ◽  
Bipolaris Sorokiniana ◽  
Spinacia Oleracea L ◽  
Inhibitor Compounds

: A series of sixteen ring-substituted N-arylcinnamamides was prepared and characterized. Primary in vitro screening of all the synthesized compounds was performed against Staphylococcus aureus, three methicillin-resistant S. aureus strains, Mycobacterium tuberculosis H37Ra, Fusarium avenaceum, and Bipolaris sorokiniana. Several of the tested compounds showed antistaphylococcal, antitubercular, and antifungal activities comparable with or higher than those of ampicillin, isoniazid, and benomyl. (2E)-N-[3,5-bis(trifluoromethyl)phenyl]-3-phenylprop-2-enamide and (2E)-3-phenyl-N-[3-(trifluoromethyl)phenyl]prop-2-enamide showed the highest activities (MICs = 22.27 and 27.47 µM, respectively) against all four staphylococcal strains and against M. tuberculosis. These compounds showed an activity against biofilm formation of S. aureus ATCC 29213 in concentrations close to MICs and an ability to increase the activity of clinically used antibiotics with different mechanisms of action (vancomycin, ciprofloxacin, and tetracycline). In time-kill studies, a decrease of CFU/mL of >99% after 8 h from the beginning of incubation was observed. (2E)-N-(3,5-Dichlorophenyl)- and (2E)-N-(3,4-dichlorophenyl)-3-phenylprop-2-enamide had a MIC = 27.38 µM against M. tuberculosis, while a significant decrease (22.65%) of mycobacterial cell metabolism determined by the MTT assay was observed for the 3,5-dichlorophenyl derivative. (2E)-N-(3-Fluorophenyl)- and (2E)-N-(3-methylphenyl)-3-phenylprop-2-enamide exhibited MICs = 16.58 and 33.71 µM, respectively, against B. sorokiniana. The screening of the cytotoxicity of the most effective antimicrobial compounds was performed using THP-1 cells, and these chosen compounds did not shown any significant lethal effect. The compounds were also evaluated for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. (2E)-N-(3,5-dichlorophenyl)-3-phenylprop-2-enamide (IC50 = 5.1 µM) was the most active PET inhibitor. Compounds with fungicide potency did not show any in vivo toxicity against Nicotiana tabacum var. Samsun. The structure–activity relationships are discussed.

scholarly journals Response of Baby Spinach (Spinacia oleracea L.) to Photoselective Nettings on Growth and Postharvest Quality

HortScience ◽  
2017 ◽  
Vol 52 (5) ◽  
pp. 719-724 ◽  
Author(s):  
Ambani R. Mudau ◽  
Puffy Soundy ◽  
Fhatuwani N. Mudau
Keyword(s):  
Antioxidant Activity ◽  
Spinacia Oleracea ◽  
Storage Period ◽  
Postharvest Quality ◽  
Flavonoid Content ◽  
C Storage ◽  
Spinacia Oleracea L ◽  
High Level ◽  
Spinach Leaves

Manipulation of microenvironments by means of photoselective nettings is widely used to improve the productivity and quality of high-value vegetables. The aim of this study was to investigate the effect of photoselective nettings on growth, productivity, and postharvest quality attributes of baby spinach. Baby spinach cv. Ohio was grown from seeds, and the trial was repeated. Plants were planted in an open field (control) and under closed nets, viz., black, pearl, yellow, and red nets. At harvest, baby spinach leaves were subjected to 4, 10, and 20 °C storage temperatures for 12 days. Crops grown under black nets and stored at 4 °C retained higher level of antioxidant activity (0.23 g·kg−1), whereas the least level of antioxidant activity was observed in baby spinach grown under red and yellow shade nets (0.01 g·kg−1). Similar trend was evident with flavonoid content where baby spinach leaves grown under black nets maintained high level of flavonoids at 4, 10, and 20 °C during storage period compared with other shade nets and the control. The study control showed a better potential in retaining antioxidant activity over red and yellow shade nets. Results showed that black shade nettings have the potential to reduce water loss, decay incidents, and maintain flavonoid content and antioxidant activity followed by pearl and yellow nets.

scholarly journals NaCl induced salt adaptive changes and enhanced accumulation of 20-hydroxyecdysone in the in vitro shoot cultures of Spinacia oleracea (L.)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Niramaya S. Muchate ◽  
Nilima S. Rajurkar ◽  
Penna Suprasanna ◽  
Tukaram D. Nikam
Keyword(s):  
Spinacia Oleracea ◽  
Shoot Cultures ◽  
Adaptive Changes ◽  
Spinacia Oleracea L ◽  
In Vitro Shoot Cultures

Effect of plant growth regulator combination and culture period on in vitro regeneration of spinach (Spinacia oleracea L.)

2012 ◽  
Vol 7 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Quyen Van Nguyen ◽  
Hyeon Jin Sun ◽  
Kyung Hwan Boo ◽  
Doseung Lee ◽  
Ji-Hyun Lee ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Regulator ◽  
Plant Growth Regulator ◽  
Spinacia Oleracea ◽  
In Vitro Regeneration ◽  
Culture Period ◽  
Spinacia Oleracea L

scholarly journals Red-Light Effects Sensitized by Methylene Blue on Nitrate Reductase from Spinach (Spinacia oleracea L.) Leaves

1984 ◽  
Vol 39 (11-12) ◽  
pp. 1079-1084 ◽  
Author(s):  
S. G. Mauriño ◽  
M. A. Vargas ◽  
P. J. Aparicio ◽  
J. M. Maldonado
Keyword(s):  
Methylene Blue ◽  
Nitrate Reductase ◽  
Spinacia Oleracea ◽  
Red Light ◽  
Deuterated Water ◽  
Anaerobic Conditions ◽  
Molybdenum Complex ◽  
Spinacia Oleracea L ◽  
Light Effects

Abstract Nitrate reductase from spinach (Spinacia oleracea L.) leaves, which had been inactivated in vitro by incubation with NADH and cyanide, was fully reactivated in minutes when irradiated in anaerobic conditions with red light in the presence of methylene blue. Both the rate and the extent of reactivation increased with light intensity (6 to 100 W·m-2) and dye concentration (1 to 10 μM). On the contrary, photoreactivation was completely abolished when NADH or ethylenediaminetetra-acetic acid were present during irradiation. We propose that methylene blue, when photo excited, exhibits a redox potential positive enough to reoxidise the CN--re-duced molybdenum complex settled in the inactive enzyme, thus causing its reactivation. On the other hand, prolonged irradiation of nitrate reductase, under air and in the presence of methylene blue, promoted an oxygen-dependent irreversible inactivation of the two partial activities of the enzyme. This inactivation was markedly enhanced in 77% deuterated water and greatly prevented by azide, which indicates that singlet oxygen is the species primarily involved in the photooxidative inactivation of the enzyme.

Sign in / Sign up

Export Citation Format

Share Document