Salt-induced accumulation of glycine betaine is inhibited by high light in durum wheat

2011 ◽  
Vol 38 (2) ◽  
pp. 139 ◽  
Author(s):  
Petronia Carillo ◽  
Danila Parisi ◽  
Pasqualina Woodrow ◽  
Giovanni Pontecorvo ◽  
Giuseppina Massaro ◽  
...  
Keyword(s):  
Amino Acids ◽  
Durum Wheat ◽  
Glycine Betaine ◽  
High Light ◽  
Light Conditions ◽  
Salt Treatment ◽  
Wheat Seedlings ◽  
Triticum Durum Desf ◽  
Tyrosine Content

In this study, we determined the effects of both salinity and high light on the metabolism of durum wheat (Triticum durum Desf. cv. Ofanto) seedlings, with a special emphasis on the potential role of glycine betaine in their protection. Unexpectedly, it appears that high light treatment inhibits the synthesis of glycine betaine, even in the presence of salt stress. Additional solutes such as sugars and especially amino acids could partially compensate for the decrease in its synthesis upon exposure to high light levels. In particular, tyrosine content was strongly increased by high light, this effect being enhanced by salt treatment. Interestingly, a large range of well-known detoxifying molecules were also not induced by salt treatment in high light conditions. Taken together, our results question the role of glycine betaine in salinity tolerance under light conditions close to those encountered by durum wheat seedlings in their natural environment and suggest the importance of other mechanisms, such as the accumulation of minor amino acids.

Influence of light intensity and salt-treatment on mode of photosynthesis and enzymes of the antioxidative response system of Mesembryanthemum crystallinum

2002 ◽  
Vol 29 (1) ◽  
pp. 13 ◽  
Author(s):  
Fernando Broetto ◽  
Ulrich Lüttge ◽  
Rafael Ratajczak
Keyword(s):  
Light Stress ◽  
High Light ◽  
Mesembryanthemum Crystallinum ◽  
Stress Factors ◽  
Lag Phase ◽  
Light Conditions ◽  
Cam Plants ◽  
Salt Treatment ◽  
Sod Activity ◽  
Antioxidative Response

The metabolic switch from C3-photosynthesis to crassulacean acid metabolism (CAM),and the antioxidative response of Mesembryanthemum crystallinum L. plants cultured under severe salt stress and high light intensities, and a combination of both stress conditions, were studied. High light conditions led to a more rapid CAM induction than salinity. The induction time was still shortened when both stress factors were combined. A main pattern observed in CAM plants was a decrease in mitochondrial Mn–superoxide dismutase (SOD) activity during the day. The activities of the chloroplastic Fe–SOD and cytosolic CuZn–SOD were increased due to salt treatment after a lag phase, while catalase activity was decreased. Combination of salt and light stress did not lead to a higher SOD activity as found after application of one stress factor alone, indicating that there is a threshold level of the oxidative stress response. The fact that salt-stressed plants grown under high light conditions showed permanent photoinhibition and lost the ability for nocturnal malate storage after 9 d of treatment indicate serious malfunction of metabolism, leading to accelerated senescence. Comparison of CuZn–SOD activity with CuZn–SOD protein amount, which was determined immunologically, indicates that the activity of the enzyme is at least partially post-translationally regulated.

Assimilate Movement in Lolium and Sorghum Leaves. II. Irradiance Effects on the Products of Photosynthesis

1976 ◽  
Vol 3 (3) ◽  
pp. 389 ◽  
Author(s):  
IF Wardlaw ◽  
C Marshall
Keyword(s):  
Amino Acids ◽  
Species Differences ◽  
High Irradiance ◽  
High Light ◽  
Light Conditions ◽  
Primary Metabolites ◽  
Lolium Temulentum ◽  
C4 Species ◽  
Sorghum Sudanense ◽  
Storage Starch

The rate of export and longitudinal movement of 14C-labelled assimilates in the phloem was found to be greater in Sorghum sudanense than in Lolium temulentum. Sucrose was the predominant metabolite translocated from the leaf in both species in both low and high light conditions. The effect of irradiance on the rate of formation and nature of the products of photosynthesis was examined using 14CO2 pulse-chase techniques and the differences in the primary metabolites closely followed those expected for a C3 and a C4 species. Reduction in irradiance reduced the rate of incorporation of 14C into sucrose, especially in Sorghum, and led to the accumulation of amino acids in both species. Although species differences in export of 14C-labelled assimilate were not apparently related to the rate of 14C incorporation into sucrose, this could account for the delay in export of 14C-labelled assimilates associated with reduced irradiance. There was a rapid initial labelling of starch and the proportion of *14C incorporated as starch was enhanced at high irradiance, particularly in Sorghum. Overall, the results support the view that there is a greater partitioning of assimilate into storage (starch) at high irradiance relative to assimilate moving into the phloem and that irradiance (in the range 20-96 W m-2) did not directly influence vein loading.

scholarly journals Hydromorphologic Sorting of In-Stream Nitrogen Uptake Across Spatial Scales

Ecosystems ◽  
2020 ◽  
Author(s):  
Ute Risse-Buhl ◽  
Christine Anlanger ◽  
Christian Noss ◽  
Andreas Lorke ◽  
Daniel von Schiller ◽  
...  
Keyword(s):  
Spatial Scales ◽  
N Uptake ◽  
High Light ◽  
Environmental Constraints ◽  
Light Conditions ◽  
Catchment Scale ◽  
Biogeochemical Fluxes ◽  
Epilithic Biofilms ◽  
Lower Biomass

AbstractNitrogen (N) uptake is a key process in stream ecosystems that is mediated mainly by benthic microorganisms (biofilms on different substrata) and has implications for the biogeochemical fluxes at catchment scale and beyond. Here, we focused on the drivers of assimilatory N uptake, especially the effects of hydromorphology and other environmental constraints, across three spatial scales: micro, meso and reach. In two seasons (summer and spring), we performed whole-reach 15N-labelled ammonium injection experiments in two montane, gravel-bed stream reaches with riffle–pool sequences. N uptake was highest in epilithic biofilms, thallophytes and roots (min–max range 0.2–545.2 mg N m−2 day−1) and lowest in leaves, wood and fine benthic organic matter (0.05–209.2 mg N m−2 day−1). At the microscale, N uptake of all primary uptake compartments except wood was higher in riffles than in pools. At the mesoscale, hydromorphology determined the distribution of primary uptake compartments, with fast-flowing riffles being dominated by biologically more active compartments and pools being dominated by biologically less active compartments. Despite a lower biomass of primary uptake compartments, mesoscale N uptake was 1.7–3.0 times higher in riffles than in pools. At reach scale, N uptake ranged from 79.6 to 334.1 mg N m−2 day−1. Highest reach-scale N uptake was caused by a bloom of thallopyhtes, mainly filamentous autotrophs, during stable low discharge and high light conditions. Our results reveal the important role of hydromorphologic sorting of primary uptake compartments at mesoscale as a controlling factor for reach-scale N uptake in streams.

Durum wheat seedling responses to simultaneous high light and salinity involve a fine reconfiguration of amino acids and carbohydrate metabolism

2016 ◽  
Vol 159 (3) ◽  
pp. 290-312 ◽  
Author(s):  
Pasqualina Woodrow ◽  
Loredana F. Ciarmiello ◽  
Maria Grazia Annunziata ◽  
Severina Pacifico ◽  
Federica Iannuzzi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Durum Wheat ◽  
Carbohydrate Metabolism ◽  
Wheat Seedling ◽  
High Light

scholarly journals Multivariateanalysis of traits associated with durum wheat seed vigor under saline conditions.

2018 ◽  
Vol 19 (2) ◽  
pp. 123-134
Author(s):  
Azzedine Fercha ◽  
◽  
Ayache Laabassi ◽  
Tarek Aissani ◽  
houki Sahraoui ◽  
...  
Keyword(s):  
Salt Stress ◽  
Durum Wheat ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Seed Vigor ◽  
Wheat Seedlings ◽  
Vigor Index ◽  
Selection For ◽  
Triticum Durum Desf ◽  
Efficient Selection

n thisstudy, the ability of germination, seedlings emergence and salt stress tolerance in durum wheat (Triticum durum Desf.) wereevaluated by multivariate analysis using eight cultivars collected from different regions of Algeria. Two-way ANOVA indicatedsignificant effects of "salt stress" and"genotype"on all the attributes of germination and seedlings growth. The principal component analysis indicated that the first and second components accounted for about 64.5% of the variation among the traits analyzed. The second component includedthe coleoptileslength,seedlingslength and vigor index, and accountedfor nearly 60% of the variation. This component representedthe ability of wheat seedlings to grow under salt stress conditions. The hierarchical cluster analysis classified the eight genotypes into two groups. Results obtained suggestedthat selection for high values of the traits such as"coleoptileslength", ‘seedlingslength’and "seedsvigor"didimprove salt tolerance of durum wheat. In addition, the cross between the genotypes classified in groups I and II may increase the genetic diversity in this species, and enable efficient selection among the progeny obtained from these crosses.

scholarly journals Photoprotection and triplet energy transfer in higher plants: the role of electronic and nuclear fluctuations

2016 ◽  
Vol 18 (16) ◽  
pp. 11288-11296 ◽  
Author(s):  
Lorenzo Cupellini ◽  
Sandro Jurinovich ◽  
Ingrid G. Prandi ◽  
Stefano Caprasecca ◽  
Benedetta Mennucci
Keyword(s):  
Energy Transfer ◽  
Higher Plants ◽  
Excess Energy ◽  
High Light ◽  
Light Conditions ◽  
Triplet Energy ◽  
Photosynthetic Organisms ◽  
Triplet Energy Transfer

Photosynthetic organisms employ several photoprotection strategies to avoid damage due to the excess energy in high light conditions.

scholarly journals Unveiling the Enigmatic Structure of TdCMO Transcripts in Durum Wheat

Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 270 ◽  
Author(s):  
Loredana Ciarmiello ◽  
Antimo Di Maro ◽  
Pasqualina Woodrow ◽  
Maria Annunziata ◽  
Ioannis Kafantaris ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Glycine Betaine ◽  
Biosynthetic Pathway ◽  
3D Structure ◽  
High Irradiance ◽  
High Light ◽  
Amino Acid Sequences ◽  
Adverse Conditions ◽  
Choline Monooxygenase ◽  
Young Leaves

Durum wheat is one of the oldest and most important edible cereal crops and its cultivation has considerable economic importance in many countries. However, adverse conditions, such as high irradiance and increasing salinity of soils, could lead to a decrease in productivity over the next few decades. Durum wheat plants under salinityare able toaccumulate glycine betaine to osmotically balance the cytosol and reduce oxidative stress, especially in young tissues. However, the synthesis of this fundamental osmolyte is inhibited by high light in T. durum even under salinity. Choline monooxygenase is the first enzyme involved in the glycine betaine biosynthetic pathway. Thus, to explain the glycine betaine inhibition, we analyzed the effect of both salinity and high light on the putative TdCMO gene expression. Thirty-eight TdCMO different transcripts were isolated in the young leaves of durum wheat grown in different stress conditions. All translated amino acid sequences, except for the TdCMO1a6 clone, showed a frame shift caused by insertions or deletions. The presence of different transcripts could depend on the presence of duplicated genes, different allelic forms, and alternative splicing events. TdCMO1a6 computational modeling of the 3D structure showed that in durum wheat, a putative CMO-like enzyme with a different Rieske type motif, is present and could be responsible for the glycine betaine synthesis.

scholarly journals Behaviour of durum wheat cultivars towards deoxynivalenol content: A multi-year assay in Italy

2017 ◽  
pp. 12-20 ◽  
Author(s):  
Tiziana Amoriello ◽  
Andreina Belocchi ◽  
Fabrizio Quaranta ◽  
Cecilia Ripa ◽  
Francesca Melini ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Linear Models ◽  
Safety Issue ◽  
Great Influence ◽  
Contamination Level ◽  
Wheat Cultivars ◽  
Generalised Linear Models ◽  
Triticum Durum Desf ◽  
Cultivar Susceptibility

The deoxynivalenol (DON) occurrence in durum wheat (Triticum durum Desf.) kernels is a key food safety issue, hence more and more attempts have been made to increase the availability of resistant cultivars. Within this framework, this work focused on the analysis of the behaviour of several durum wheat cultivars widely grown in Italy in relation to the level of deoxynivalenol contamination in whole milled kernels. A total of 2844 samples were submitted for deoxynivalenol analysis by enzyme-linked immuno-sorbent assay. The statistical analysis by generalised linear models provided a trend ranking of durum wheat cultivars on the basis of the deoxynivalenol contamination level, depending on each cultivation area assayed. This study provided a better understanding of cultivar susceptibility to mycotoxin accumulation in grains. The role of the factor cultivar has clearly emerged. However, other environmental factors, such as growing area, have a great influence on the DON concentration levels in the cultivars tested.

Nitrate reductase in durum wheat seedlings as affected by nitrate nutrition and salinity

2005 ◽  
Vol 32 (3) ◽  
pp. 209 ◽  
Author(s):  
Petronia Carillo ◽  
Gabriella Mastrolonardo ◽  
Francesco Nacca ◽  
Amodio Fuggi
Keyword(s):  
Nitrate Reductase ◽  
Durum Wheat ◽  
Shoot Growth ◽  
Nitrogen Availability ◽  
High Salinity ◽  
Inhibitory Effect ◽  
Salt Treatment ◽  
Signal Molecule ◽  
Wheat Seedlings ◽  
Metabolite Content

The combined effects of nitrate (0, 0.1, 1, 10 mm) and salt (0, 100 mm NaCl) on nitrogen metabolism in durum wheat seedlings were investigated by analysis of nitrate reductase (NR) expression and activity, and metabolite content. High salinity (100 mm NaCl) reduced shoot growth more than root growth. The effect was independent of nitrate concentration. NR mRNA was present at a low level in both leaves and roots of plants grown in a nitrogen-free medium. NaCl increased NR mRNA at low nitrate, suggesting that chloride can mimic nitrate as a signal molecule to induce transcription in both roots and leaves. However, the level of NR protein remained low in salt-stressed plants, indicating an inhibitory effect of salt on translation of NR mRNA or an increase in protein degradation. The lower activity of nitrate reductase in leaves of high-nitrate treated plants under salinity suggested a restriction of NO3– transport to the shoot under salinity. Salt treatment promoted photorespiration, inhibiting carbohydrate accumulation in plants grown on low nitrate media. Under salinity free amino acids, in particular proline and asparagine, and glycine betaine could function as osmolytes to balance water potential within the cell, especially when nitrogen availability exceeded the need for growth.

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