Nitrogen metabolism in durum wheat under salinity: accumulation of proline and glycine betaine

2008 ◽  
Vol 35 (5) ◽  
pp. 412 ◽  
Author(s):  
Petronia Carillo ◽  
Gabriella Mastrolonardo ◽  
Francesco Nacca ◽  
Danila Parisi ◽  
Angelo Verlotta ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Glycine Betaine ◽  
Nitrogen Nutrition ◽  
Compatible Solutes ◽  
Glutamate Synthase ◽  
Nitrogen Supply ◽  
Carbon And Nitrogen ◽  
Young Leaves ◽  
Prolonged Stress ◽  
Low Nitrogen

We studied the effect of salinity on amino acid, proline and glycine betaine accumulation in leaves of different stages of development in durum wheat under high and low nitrogen supply. Our results suggest that protective compounds against salt stress are accumulated in all leaves. The major metabolites are glycine betaine, which preferentially accumulates in younger tissues, and proline, which is found predominantly in older tissues. Proline tended to accumulate early, at the onset of the stress, while glycine betaine accumulation was observed during prolonged stress. Nitrate reductase (NR) and glutamate synthase (GOGAT) are positively correlated with these compatible solutes: proline is associated with NR in the oldest leaves of high-nitrate plants and glycine betaine is associated with GOGAT in the youngest leaves of both low- and high-nitrate plants. In high-nitrate conditions proline accounts for more than 39% of the osmotic adjustment in the cytoplasmic compartments of old leaves. Its nitrogen-dependent accumulation may offer an important advantage in that it can be metabolised to allow reallocation of energy, carbon and nitrogen from the older leaves to the younger tissues. The contribution of glycine betaine is higher in young leaves and is independent of nitrogen nutrition.

Colonization of Orchis morio protocorms by a mycorrhizal fungus: effects of nitrogen nutrition and glyphosate in modifying the responses

1995 ◽  
Vol 73 (8) ◽  
pp. 1128-1140 ◽  
Author(s):  
H. F. Beyrle ◽  
S. E. Smith ◽  
C. M. M. Franco ◽  
R. L. Peterson
Keyword(s):  
Mycorrhizal Fungi ◽  
Phenylalanine Ammonia Lyase ◽  
Shikimic Acid ◽  
Nitrogen Nutrition ◽  
Mycorrhizal Fungus ◽  
Fungal Growth ◽  
Soft Rot ◽  
Nitrogen Supply ◽  
Wall Thickening ◽  
Low Nitrogen

Effects of nitrogen nutrition and application of glyphosate (as Roundup™) on the interactions between protocorms of Orchis morio and a mycorrhizal Rhizoctonia species were investigated. Protocorms for all experiments were raised clonally in liquid culture. Split plates were used to separate the direct effects of composition of the media from effects mediated via the fungus. Mycorrhizal interactions, including coil formation and prolonged protocorm growth, were established when a relatively low nitrogen supply to the fungus (as NH4)2SO4) was combined with a high carbohydrate supply. Rejection of the fungus, associated with phenolic production, wall thickening, and lack of protocorm growth, was observed with high-carbon, high-nitrogen medium. Low carbohydrate supply, with either high or low nitrogen supply, was associated with breakaway parasitism, symptoms of soft rot, and lack of subsequent protocorm growth. Application of glyphosate at 0.5 or 1.0 mM had no effect on fungal growth and at 1.0 mM did not cause death of asymbiotic protocorms, but resulted in failure of mycorrhizal initiation. Coils were never formed and the fungus ramified through the tissues of the protocorms. The parasitism induced by glyphosate differed from breakaway parasitism, and there were no symptoms of soft rot. Assays for activity of phenylalanine ammonia lyase (PAL) and for orchinol were carried out to assess the effects of the treatments on the shikimic acid pathway. Low activity of PAL and low quantities of orchinol (together with another unidentified phenolic compound) were detected in asymbiotic protocorms. Concentrations of both were increased in the presence of the fungus, but no significant differences were observed in the various symbiotic responses in the absence of glyphosate. This is the first report of the presence of orchinol in orchid protocorms. Previous work has always been carried out on tubers, which are not usually colonized by the mycorrhizal fungi. Application of glyphosate resulted in increases in both PAL activity and orchinol production. The results are discussed in the context of orchid–fungus interactions and the mechanism of glyphosate action. Key words: orchid, mycorrhiza, parasitism, cell walls, glyphosate, phenylalanine ammonia lyase (PAL), orchinol.

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.

Effect of tiller age and time of nitrogen stress on seed production of Paspalum plicatulum

1973 ◽  
Vol 81 (2) ◽  
pp. 219-229 ◽  
Author(s):  
P. A. Chadhokar ◽  
L. R. Humphreys
Keyword(s):  
Ammonium Nitrate ◽  
Seed Size ◽  
Seed Yield ◽  
Growth And Development ◽  
Nitrogen Nutrition ◽  
Development Stage ◽  
Nitrogen Supply ◽  
Nitrogen Stress ◽  
Floral Initiation ◽  
Final Maturation

SummaryPaspalum plicatulum was grown at Brisbane in boxes of sand receiving basal nutrients and frequent irrigation; weekly levels of ammonium nitrate application were varied according to growth and development stage.The rate of tiller appearance increased to a maximum 40–50 days after sowing and almost ceased thereafter. Tiller leaf number, survival, fertility, inflorescence branching, seeds per raceme and seed size were positively related to tiller age. Young tillers were more sensitive to variations in nitrogen supply than old tillers.Adequate nitrogen nutrition during the vegetative phase from sowing to floral initiation (93 days) increased tiller and hence inflorescence density; increased inflorescence branching was compensated by fewer seeds per raceme. Good nitrogen nutrition during the phase from floral initiation to inflorescence exsertion (142 days) increased survival of late-formed tillers and hence inflorescence density; inflorescence branching, seeds per raceme and seed size were also increased. Nitrogen stress during the final maturation phase did not affect seed yield.

The Influence of Carbon and Nitrogen Nutrition on Growth and Sterolinduced Sexuality of Pythium sp. PRL 2142

Mycologia ◽  
1969 ◽  
Vol 61 (6) ◽  
pp. 1096 ◽  
Author(s):  
J. J. Child ◽  
G. Defago ◽  
R. H. Haskins
Keyword(s):  
Nitrogen Nutrition ◽  
Carbon And Nitrogen

scholarly journals Gbu Glycine Betaine Porter and Carnitine Uptake in Osmotically Stressed Listeria monocytogenes Cells

2002 ◽  
Vol 68 (11) ◽  
pp. 5647-5655 ◽  
Author(s):  
Mary Lou Mendum ◽  
Linda Tombras Smith
Keyword(s):  
Listeria Monocytogenes ◽  
Transport System ◽  
Glycine Betaine ◽  
Compatible Solutes ◽  
High Salt ◽  
Uptake System ◽  
Food Borne ◽  
Protein Mutants ◽  
Carnitine Uptake ◽  
Do So

ABSTRACT The food-borne pathogen Listeria monocytogenes grows actively under high-salt conditions by accumulating compatible solutes such as glycine betaine and carnitine from the medium. We report here that the dominant transport system for glycine betaine uptake, the Gbu porter, may act as a secondary uptake system for carnitine, with a Km of 4 mM for carnitine uptake and measurable uptake at carnitine concentrations as low as 10 μM. This porter has a Km for glycine betaine uptake of about 6 μM. The dedicated carnitine porter, OpuC, has a Km for carnitine uptake of 1 to 3 μM and a V max of approximately 15 nmol/min/mg of protein. Mutants lacking either opuC or gbu were used to study the effects of four carnitine analogs on growth and uptake of osmolytes. In strain DP-L1044, which had OpuC and the two glycine betaine porters Gbu and BetL, triethylglycine was most effective in inhibiting growth in the presence of glycine betaine, but trigonelline was best at inhibiting growth in the presence of carnitine. Carnitine uptake through OpuC was inhibited by γ-butyrobetaine. Dimethylglycine inhibited both glycine betaine and carnitine uptake through the Gbu porter. Carnitine uptake through the Gbu porter was inhibited by triethylglycine. Glycine betaine uptake through the BetL porter was strongly inhibited by trigonelline and triethylglycine. These results suggest that it is possible to reduce the growth of L. monocytogenes under osmotically stressful conditions by inhibiting glycine betaine and carnitine uptake but that to do so, multiple uptake systems must be affected.

Humectant Permeability Influences Growth and Compatible Solute Uptake by Staphylococcus aureus Subjected to Osmotic Stress

2002 ◽  
Vol 65 (6) ◽  
pp. 1008-1015 ◽  
Author(s):  
ODDUR VILHELMSSON ◽  
KAREN J. MILLER
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Chloride ◽  
Water Activity ◽  
Glycine Betaine ◽  
Compatible Solutes ◽  
Foodborne Pathogen ◽  
Compatible Solute ◽  
Solute Uptake ◽  
Stressed Cells ◽  
Carnitine Uptake

The effects of different humectants (sodium chloride, sucrose, and glycerol) on the growth of and compatible solute (glycine betaine, proline, and carnitine) uptake by the osmotolerant foodborne pathogen Staphylococcus aureus were investigated. While growth in the presence of the impermeant humectants sodium chloride and sucrose induced the accumulation of proline and glycine betaine by cells, growth in the presence of the permeant humectant glycerol did not. When compatible solutes were omitted from low-water-activity media, growth was very poor in the presence of impermeant humectants. In contrast, the addition of compatible solutes had essentially no effect on growth when cells were grown in low-water-activity media containing glycerol as the humectant. Carnitine was found to accumulate to high intracellular levels in osmotically stressed cells when proline and glycine betaine were absent, making it a potentially important compatible solute for this organism.

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