scholarly journals Potassium Application Boosts Photosynthesis and Sorbitol Biosynthesis and Accelerates Cold Acclimation of Common Plantain (Plantago major L.)

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1259
Author(s):  
Li-Hsuan Ho ◽  
Regina Rode ◽  
Maike Siegel ◽  
Frank Reinhardt ◽  
H. Ekkehard Neuhaus ◽  
...  
Keyword(s):  
Cold Acclimation ◽  
Carbon Assimilation ◽  
Leaf Tissue ◽  
Plant Performance ◽  
Photochemical Quenching ◽  
Dependent Manner ◽  
Plantago Major ◽  
High Potassium ◽  
Source To Sink ◽  
Sink Development

Potassium (K) is essential for the processes critical for plant performance, including photosynthesis, carbon assimilation, and response to stress. K also influences translocation of sugars in the phloem and regulates sucrose metabolism. Several plant species synthesize polyols and transport these sugar alcohols from source to sink tissues. Limited knowledge exists about the involvement of K in the above processes in polyol-translocating plants. We, therefore, studied K effects in Plantago major, a species that accumulates the polyol sorbitol to high concentrations. We grew P. major plants on soil substrate adjusted to low-, medium-, or high-potassium conditions. We found that biomass, seed yield, and leaf tissue K contents increased in a soil K-dependent manner. K gradually increased the photosynthetic efficiency and decreased the non-photochemical quenching. Concomitantly, sorbitol levels and sorbitol to sucrose ratio in leaves and phloem sap increased in a K-dependent manner. K supply also fostered plant cold acclimation. High soil K levels mitigated loss of water from leaves in the cold and supported cold-dependent sugar and sorbitol accumulation. We hypothesize that with increased K nutrition, P. major preferentially channels photosynthesis-derived electrons into sorbitol biosynthesis and that this increased sorbitol is supportive for sink development and as a protective solute, during abiotic stress.

scholarly journals Sucrose Utilization for Improved Crop Yields: A Review Article

2021 ◽  
Vol 22 (9) ◽  
pp. 4704
Author(s):  
Oluwaseun Olayemi Aluko ◽  
Chuanzong Li ◽  
Qian Wang ◽  
Haobao Liu
Keyword(s):  
Plant Growth ◽  
Crop Yields ◽  
Carbon Assimilation ◽  
Primary Energy ◽  
Environmental Cues ◽  
Sucrose Transport ◽  
Source To Sink ◽  
Photosynthetic Carbon ◽  
Sink Development ◽  
The Impact

Photosynthetic carbon converted to sucrose is vital for plant growth. Sucrose acts as a signaling molecule and a primary energy source that coordinates the source and sink development. Alteration in source–sink balance halts the physiological and developmental processes of plants, since plant growth is mostly triggered when the primary assimilates in the source leaf balance with the metabolic needs of the heterotrophic sinks. To measure up with the sink organ’s metabolic needs, the improvement of photosynthetic carbon to synthesis sucrose, its remobilization, and utilization at the sink level becomes imperative. However, environmental cues that influence sucrose balance within these plant organs, limiting positive yield prospects, have also been a rising issue over the past few decades. Thus, this review discusses strategies to improve photosynthetic carbon assimilation, the pathways actively involved in the transport of sucrose from source to sink organs, and their utilization at the sink organ. We further emphasize the impact of various environmental cues on sucrose transport and utilization, and the strategic yield improvement approaches under such conditions.

A freeze-etch study of plant cell walls for ectodesmata

1974 ◽  
Vol 52 (9) ◽  
pp. 2033-2036 ◽  
Author(s):  
N. C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Leaf Tissue ◽  
Physicochemical Characteristics ◽  
Outer Cell ◽  
Plantago Major ◽  
Plant Cell Walls ◽  
Phaseolus Vulgaris L ◽  
Epidermal Cell Wall ◽  
Outer Cell Wall

Leaf tissue of Phaseolus vulgaris L. and Plantago major L. was prepared by the freeze-etch technique and examined in the electron microscope for the presence of ectodesmata. No structures analagous to ectodesmata observed with light microscopy could be found in freeze-etched preparations of chemically unfixed material or in material fixed only in glutaraldehyde. Objects appearing as broad, shallow, granular areas in the epidermal cell wall beneath the cuticle were observed in leaf replicas after fixation in complete sublimate fixative, the acid components of the sublimate fixative, or mercuric chloride alone. Because of their distribution and location, these objects can be considered analagous to ectodesmata observed by light microscopists. Because these areas occur only in chemically fixed walls and are localized within the walls in discrete areas, their presence supports the contention that ectodesmata are sites in the outer cell wall with defined physicochemical characteristics.

Using Sun-induced fluorescence and Carbonyl Sulfide flux to assess the response to seasonal heatwave in a citrus orchard

2020 ◽  
Author(s):  
Amnon Cochavi ◽  
Madi Amer ◽  
Rafael Stern ◽  
Dan Yakir
Keyword(s):  
Heat Stress ◽  
Carbonyl Sulfide ◽  
Carbon Assimilation ◽  
Net Ecosystem Exchange ◽  
Pulse Amplitude ◽  
Full Scale ◽  
Photochemical Quenching ◽  
Air Temperatures ◽  
Net Assimilation ◽  
Non Photochemical Quenching

<p>Springtime heatwaves are common phenomena in the Mediterranean region, named ‘Sharav’ or ‘Hamsin’. During these heatwaves, air temperatures (Ta) and vapor pressure demand (VPD) increase rapidly over 3-5 days, followed by a dramatic drop of at least 5℃ in Ta and 1 kPa in VPD back to the pre-event values.</p><p>Here, we used our mobile lab in an irrigated lemon orchard in Rehovot, Israel to carry out eddy covariance (EC) flux measurements of net ecosystem exchange of CO<sub>2</sub> (NEE), water vapor, and carbonyl sulfide (COS), as well as canopy Sun-induced fluorescence (SIF) together with other spectral indices (NDVI, PRI, NIRv). This was supplemented with leaf-scale measurements of Pulse Amplitude modulated (PAM). Five heatwave events were detected during a two-months measurement campaign. Two other events were defined as intermediate days, with VPD values higher than normal but lower than in the full-scale heatwaves.</p><p>During both the heatwave and intermediate days, the COS fluxes (Fcos), far-red SIF, and electron transport rate (ETR), decreased during midday to the same level, compared to the control days. In contrast, NEE responded differentially between the heatwave and intermediate days, with midday values of -5.9±0.9, -3.7±0.7 and -0.69±0.62 µmol m<sup>-2</sup>s<sup>-1</sup> CO<sub>2</sub>, in the control, intermediate and heatwave days, respectively. No differences were detected in both NDVI and NIRv values. The PRI index, related to energy transfer through the non-photochemical quenching (NPQ) pathway, showed a similar pattern to that of NEE. The recovery of the ecosystem from the heatwave events was rapid and occurred within a day after the end of the events.</p><p>The results indicate a link between the far-red SIF and the ETR in the response to the heatwaves. Moreover, the reduction in far-red SIF was negatively associated with the increase in NPQ, which was reflected in both the spectral (PRI) and the PAM (NPQ value) measurements. The observed decrease in Fcos is expected to reflect a decrease in stomatal conductance to a similar extent in the heatwave and intermediate days. However, the lower rate of CO<sub>2</sub> assimilation in the full-scale heat wave days suggests that additional factors further decreased its rates beyond that limited by conductance. This can be related to the increased effect of the heat stress on other energy-demanding pathways (e.g. photorespiratory, isoprene production) that can suppress net assimilation in these days.</p><p>This work demonstrated that the relation between carbon assimilation and far-red SIF can be complex, and that combining SIF and COS measurements can help partition the effects of heat stress on conductance and other physiological effects.</p>

Influence of atrial natriuretic factor on uptake, intracellular distribution, and release of norepinephrine in rat adrenal medulla

1993 ◽  
Vol 71 (3-4) ◽  
pp. 195-200 ◽  
Author(s):  
M. S. Vatta ◽  
L. G. Bianciotti ◽  
B. E. Fernández
Keyword(s):  
Adrenal Medulla ◽  
Atrial Natriuretic Factor ◽  
Muscle Tone ◽  
Intracellular Distribution ◽  
Dependent Manner ◽  
High Potassium ◽  
Norepinephrine Uptake ◽  
Arterial Blood ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

Several studies have demonstrated that atrial natriuretic factor can bind to adrenal medulla cells. Furthermore, atrial natriuretic factor immunoreactivity has been identified in chromaffin cells. The aim of the present work was to investigate atrial natriuretic factor effects on the uptake, intracellular distribution, and release of norepinephrine in the rat adrenal medulla. Results showed that 100 nM atrial natriuretic factor induced a rapid increase of norepinephrine uptake during the first minute of the incubation period. This increase was maintained for up to 60 min. In addition, only neuronal norepinephrine uptake was increased by the natriuretic factor; non-neuronal norepinephrine uptake was unaltered. Atrial natriuretic factor modified the intracellular distribution of the amine store: the granular fraction of norepinephrine increased, while the cytosolic fraction decreased. On the other hand, different concentrations (10, 50, and 100 nM) of the atrial factor decreased spontaneous [3H]norepinephrine output in a concentration-dependent manner. Furthermore, atrial natriuretic factor (10 nM) also reduced high potassium solution evoked secretion of norepineprhine. These results suggest that atrial natriuretic factor modulates sympathetic activity in the rat adrenal medulla. These effects of atrial natriuretic factor may be related to the catecholamine peripheral mechanism involved in the regulation of arterial blood pressure, smooth muscle tone, metabolic activity, etc.Key words: adrenal medulla, atrial natriuretic factor, intracellular norepinephrine distribution, norepinephrine release, norepineprhine uptake.

scholarly journals Evaluating Plant Potassium Status

2020 ◽  
pp. 219-261
Author(s):  
T. Scott Murrell ◽  
Dharma Pitchay
Keyword(s):  
Growth And Development ◽  
Nutrient Balance ◽  
Leaf Tissue ◽  
Large Data ◽  
Plant Performance ◽  
Data Sets ◽  
Nutrient Deficiencies ◽  
Correlation Studies ◽  
Remote Sensing Technique ◽  
Crop Growth And Development

AbstractSeveral methods exist for evaluating plant nutritional status. Looking for visual deficiency symptoms is perhaps the simplest approach, but once symptoms appear, crop performance has already been compromised. Several other techniques have been developed. All of them require correlation studies to provide plant performance interpretations. Reflectance is a remote sensing technique that detects changes in light energy reflected by plant tissue. It has proven successful in detecting nutrient deficiencies but does not yet have the ability to discriminate among more than one deficiency. Chemical assays of leaf tissue, known as tissue tests, require destructive sampling but are the standard against which other assessments are compared. Sufficiency ranges provide concentrations of each nutrient that are considered adequate for crop growth and development. They consider nutrients in isolation. Other approaches have been developed to consider how the concentration of one nutrient in tissue impacts the concentrations of other nutrients. These approaches strive to develop guidelines for maintaining nutrient balance within the plant. All approaches require large data sets for interpretation.

scholarly journals Arabidopsis Sucrose Transporter 4 (AtSUC4) is Involved in Root Response of High Content Sucrose-Growth Via IAA- and ABA- Dependent Manner

2021 ◽  
Author(s):  
Si-Wen Liu ◽  
Li-Ding Zhang ◽  
Jia-Yu Gao ◽  
Tian-Tian Dong ◽  
Tong Zhang ◽  
...  
Keyword(s):  
Primary Root ◽  
Group Iv ◽  
Sucrose Transporter ◽  
Dependent Manner ◽  
External Application ◽  
Sucrose Transporters ◽  
Source To Sink ◽  
Root Response ◽  
High Sucrose

Abstract Source-to-sink transport of sucrose mediated by sucrose transporters (SUCs) is one of the major determinants of plant growth. However, the role of AtSUC4, the only member of Group IV sucrose transporter in Arabidopsis, was undervalued in sink organ during seedling period. In our study, the primary root length of the atsuc4 mutants was significantly longer than that of the wild-type (WT) under exogenous 4% and 6% sucrose treatment. But this phenotype could not be imitated by external application of glucose or mannitol. It means that the atsuc4 mutants were insensitive to high sucrose stress compared with WT. Meanwhile, HPLC-MS/MS results showed that the root of atsuc4 mutants accumulated less sucrose and ABA and more IAA content compared with WT on 4% and 6% sucrose supplementation. Transcriptome analysis showed that many key genes involved in IAA and ABA signals were respective stimulated and repressed in the atsuc4 mutants, respectively. Taken together, we concluded that the deficiency of AtSUC4, not only reducing the transported and uptaked of sucrose, but also as a signal, may be collaborated with IAA and ABA to regulate root growth under high sucrose stress. This study confirmed the new function of AtSUC4, and provided an promising candidate gene for improving tolerance to high sucrose stress.

scholarly journals Does Spraying of Atrazine on Triazine-Resistant Canola Hybrid Impair Photosynthetic Processes?

2019 ◽  
Vol 37 ◽  
Author(s):  
M.R. DURIGON ◽  
A.S. CAMERA ◽  
J. CECHIN ◽  
L. VARGAS ◽  
G. CHAVARRIA
Keyword(s):  
Electron Transport ◽  
Block Design ◽  
Winter Season ◽  
Carbon Assimilation ◽  
Photochemical Quenching ◽  
Assimilation Rate ◽  
Biochemical Processes ◽  
Randomized Block Design ◽  
Carbon Assimilation Rate ◽  
Rotation Crop

ABSTRACT: Canola is an important rotation crop for the winter season and the use of atrazine-resistant hybrids can lead to an increase in yield. This work was aimed at evaluating the effect of atrazine on photochemical and biochemical processes of photosynthesis in triazine-resistant canola. The experiment was conducted in a greenhouse, with triazine-resistant hybrid Hyola® 555TT, in a randomized block design with three replications. The treatments consisted of application or no application of atrazine on canola plants. The plants were assessed at one, three, five, and eight days after application (DAA) for chlorophyll indexes, modulated chlorophyll a fluorescence and gas exchange. Chlorophyll indexes were higher in canola plants treated with atrazine. Application of atrazine caused an increase in fluorescence at steady state and a reduction in quantum efficiency of photosystem II and electron transport rate, at 1 DAA, and a reduction in photochemical quenching, at 1 and 3 DAA. Lower stomatal conductance, at 1 DAA, and higher net carbon assimilation rate, at 8 DAA, were found in plants treated with atrazine. The application of atrazine temporarily reduces electron transport between photosystems and increases chlorophyll indexes in resistant canola plants, raising the net carbon assimilation rate at eight days after application.

scholarly journals Characteristics of Mango Leaf Photosynthetic Inhibition by Enhanced UV-B Radiation

Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 557
Author(s):  
Hong Wang ◽  
Yujian Guo ◽  
Jianjun Zhu ◽  
Kun Yue ◽  
Kaibing Zhou
Keyword(s):  
Chlorophyll A ◽  
Mangifera Indica ◽  
Soluble Sugar ◽  
Intercellular Co2 Concentration ◽  
Carbon Assimilation ◽  
Co2 Concentration ◽  
Photochemical Reactions ◽  
Photochemical Quenching ◽  
Hill Reaction ◽  
Photosynthetic Inhibition

To investigate the photosynthetic change characteristics of mango leaves under enhanced UV-B radiation, adult ‘Tainong No. 1′ mango (Mangifera indica) trees were treated (N = nine individuals) with simulated enhanced UV-B radiation [24 and 96 kJ/(m2·d)] in the field, and the photochemical reactions, activities of key enzymes in carbon assimilation, and the expression of genes were observed. The results showed that compared with the control, there was a decrease in tree yield, soluble sugar, sugar–acid ratio, and vitamin C of the fruits under the 96 kJ/(m2·d) treatment, while no significant changes were observed under 24 kJ/(m2·d). After 20 or 40 days, the leaves’ net photosynthetic rate (Pn), stomatal conductance (Sc), transpiration rate (Tr), intercellular CO2 concentration (Ci), and chlorophyll a/b under exposure to 96 kJ/(m2·d) of UV-B were significantly lower than in the control, whereas chlorophyll a, chlorophyll b, carotenoids, Hill reaction activity, photochemical quenching coefficient (qP), and Rubisco activities were significantly higher. In contrast, the Hill activity and Rubisco activity under 24 kJ/(m2·d) were significantly higher than the control, and increased by 350% and 30.8%, respectively, while Pn, Sc, Tr, Ci, and the content of photosynthetic pigments were similar to the control. The expression of gene coding the Rubisco big subunit (rbcL) was inhibited by the 96 kJ/(m2·d) treatment. We conclude that stomatal limitation was directly induced by 96 kJ/(m2·d), resulting in the inhibition of photosynthesis and the reduction in yield and deterioration of the quality of mango.

Daphnetin methylation stabilizes the activity of phosphoribulokinase in wheat during cold acclimation

2012 ◽  
Vol 90 (5) ◽  
pp. 657-666
Author(s):  
Khalil Kane ◽  
Amira Moheb ◽  
Yukihara Fukushi ◽  
René Roy ◽  
Norman P.A Hüner ◽  
...  
Keyword(s):  
Cold Acclimation ◽  
Calvin Cycle ◽  
Biological Significance ◽  
Deae Cellulose ◽  
Triticum Aestivum L ◽  
Spectrometric Analysis ◽  
Dependent Manner ◽  
Aerial Parts ◽  
Dose Dependent ◽  
Excitation Pressure

The methylation of daphnetin (7,8-dihydroxycoumarin) to its 8-methyl derivative is catalyzed by a wheat (Triticum aestivum L.) O-methyltransferase (TaOMT1). This enzyme is regulated by cold and photosystem II excitation pressure (plastid redox state). Here, we investigated the biological significance of this methylation and its potential role in modulating the activity of kinases in wheat. To identify the potential kinases that may interact with daphnetin in wheat, the soluble protein extract from aerial parts of cold-acclimated wheat was purified by DEAE-cellulose separation and affinity chromatography on a daphnetin derivative (7,8-dihydroxy-4-coumarin acetic acid)-EAH sepharose column. Mass spectrometric analysis indicated that wheat phosphoribulokinase (TaPRK) is the major kinase that binds to daphnetin. This TaPRK plays an important role in regulating the flow of carbon through the Calvin cycle, by catalyzing the final step in the regeneration of ribulose 1,5-bisphosphate from ribulose-5-phosphate (Ru5P) and ATP. The activities of TaPRK, endogenous or recombinant, are inhibited by daphnetin in a specific and dose-dependent manner, but not by its monomethyl derivative (7-methyl, 8-hydroxycoumarin). Furthermore, HPLC-MS analysis of wheat extracts reveals that 7,8-dimethoxycoumarin is more abundant than its monomethyl derivative. The results also show that cold acclimation does not alter the level of TaPRK mRNA or its enzyme activity, and thus ensures the stable generation of ribulose 1,5-biphosphate.

scholarly journals Identification of adrenal genes regulated in a potassium-dependent manner

2010 ◽  
Vol 45 (4) ◽  
pp. 193-206 ◽  
Author(s):  
Alexander Dierks ◽  
Urs D Lichtenauer ◽  
Simone Sackmann ◽  
Ariadni Spyroglou ◽  
Igor Shapiro ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Adrenal Cortex ◽  
Adrenal Glands ◽  
Indirect Evidence ◽  
Dependent Manner ◽  
Aldosterone Secretion ◽  
Short Term ◽  
High Potassium ◽  
Potassium Stimulation

Potassium and angiotensin II are the main stimulators of aldosterone secretion from the adrenal cortex. As potassium-induced in vivo gene regulation in the adrenal cortex has not been studied in detail, we applied a stepwise screening approach: first, we investigated the effects of chronic potassium substitution in mice. Microarray analysis of adrenal glands revealed a set of genes (set A) that were counter-regulated in a high potassium (HP) and low potassium substitution group, while others (set B) were highly upregulated in the HP intake group. In a second step, time dependency of expression changes of these pre-defined genes was studied following short-term potassium stimulation experiments in vivo. Thirdly, dose dependency of potassium-induced gene regulation was investigated in vitro. Finally, to provide indirect evidence for the potential relevance of the detected changes for autonomous aldosterone secretion, expression analysis of aldosterone-producing adenomas was compared with normal adrenal glands. While most investigated genes were similarly regulated following long- and short-term potassium stimulation in vivo, observed changes were reproducible in NCI h295R adrenocortical cells mostly for the set of genes identified in the HP group (set B). Similarly, in Conn's adenomas, mostly genes from set B displayed changes in expression pattern in comparison to normal adrenal glands, while genes from set A were mostly unchanged. Thus, while in vivo models can help in identifying genes potentially involved in potassium-dependent aldosterone secretion, these findings also underline the necessity to interpret potassium-induced gene regulation on the basis of the experimental setting.

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