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 Identifying Genes Involved in Alkaloid Biosynthesis in Vinca minor through Transcriptomics and Gene Co-Expression Analysis

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1595
Author(s):  
Emily Amor Stander ◽  
Liuda Johana Sepúlveda ◽  
Thomas Dugé de Bernonville ◽  
Inês Carqueijeiro ◽  
Konstantinos Koudounas ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Biosynthetic Pathway ◽  
Fluorescent Proteins ◽  
Light Exposure ◽  
Indole Alkaloids ◽  
High Light ◽  
Alkaloid Biosynthesis ◽  
Vinca Minor ◽  
Young Leaves ◽  
Derivatives Of

The lesser periwinkle Vinca minor accumulates numerous monoterpene indole alkaloids (MIAs) including the vasodilator vincamine. While the biosynthetic pathway of MIAs has been largely elucidated in other Apocynaceae such as Catharanthus roseus, the counterpart in V. minor remains mostly unknown, especially for reactions leading to MIAs specific to this plant. As a consequence, we generated a comprehensive V. minor transcriptome elaborated from eight distinct samples including roots, old and young leaves exposed to low or high light exposure conditions. This optimized resource exhibits an improved completeness compared to already published ones. Through homology-based searches using C. roseus genes as bait, we predicted candidate genes for all common steps of the MIA pathway as illustrated by the cloning of a tabersonine/vincadifformine 16-O-methyltransferase (Vm16OMT) isoform. The functional validation of this enzyme revealed its capacity of methylating 16-hydroxylated derivatives of tabersonine, vincadifformine and lochnericine with a Km 0.94 ± 0.06 µM for 16-hydroxytabersonine. Furthermore, by combining expression of fusions with yellow fluorescent proteins and interaction assays, we established that Vm16OMT is located in the cytosol and forms homodimers. Finally, a gene co-expression network was performed to identify candidate genes of the missing V. minor biosynthetic steps to guide MIA pathway elucidation.

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.

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.

Does Astaxanthin Protect Haematococcus against Light Damage?

1998 ◽  
Vol 53 (1-2) ◽  
pp. 93-100 ◽  
Author(s):  
Lu Fan ◽  
Avigad Vonshak ◽  
Aliza Zarka ◽  
Sammy Boussiba
Keyword(s):  
Light Intensity ◽  
Light Stress ◽  
Phosphate Starvation ◽  
High Light Intensity ◽  
High Irradiance ◽  
High Light ◽  
Protective Agent ◽  
Light Damage ◽  
Low Light ◽  
Very High

Abstract The photoprotective function of the ketocarotenoid astaxanthin in Haematococcus was questioned. When exposed to high irradiance and/or nutritional stress, green Haematococcus cells turned red due to accumulation of an immense quantity of the red pigment astaxanthin. Our results demonstrate that: 1) The addition of diphenylamine, an inhibitor of astaxanthin biosynthesis, causes cell death under high light intensity; 2) Red cells are susceptible to high light stress to the same extent or even higher then green ones upon exposure to a very high light intensity (4000 μmol photon m-2 s-1); 3) Addition of 1O2 generators (methylene blue, rose bengal) under noninductive conditions (low light of 100 (μmol photon m-2 s-1) induced astaxanthin accumulation. This can be reversed by an exogenous 1O2 quencher (histidine); 4) Histidine can prevent the accumulation of astaxanthin induced by phosphate starvation. We suggest that: 1) Astaxanthin is the result of the photoprotection process rather than the protective agent; 2) 1O2 is involved indirectly in astaxanthin accumulation process.

scholarly journals The endogenous choline supply limits glycine betaine synthesis in transgenic tobacco expressing choline monooxygenase

1998 ◽  
Vol 16 (4) ◽  
pp. 487-496 ◽  
Author(s):  
Michael L. Nuccio ◽  
Brenda L. Russell ◽  
Kurt D. Nolte ◽  
Bala Rathinasabapathi ◽  
Douglas A. Gage ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Glycine Betaine ◽  
Choline Monooxygenase

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.

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

Essential Region for 3-N Methylation in N-Methyltransferases Involved in Caffeine Biosynthesis

2010 ◽  
Vol 65 (3-4) ◽  
pp. 257-265 ◽  
Author(s):  
Kouichi Mizuno ◽  
Shin-ichi Kurosawa ◽  
Yuko Yoshizawa ◽  
Misako Kato
Keyword(s):  
Biosynthetic Pathway ◽  
Initial Step ◽  
Amino Acid Sequences ◽  
Histidine Residue ◽  
Substrate Specificities ◽  
Caffeine Synthase ◽  
Caffeine Biosynthesis ◽  
Restricted Region ◽  
Essential Region ◽  
Theobromine Synthase

The caffeine biosynthetic pathway is composed of three methylation steps, and N-methyltransferase catalyzing each step has high substrate specificity. Since the amino acid sequences among coffee 7-methylxanthosine synthase (CmXRS1), theobromine synthase, and caffeine synthase are highly homologous to each other, these substrate specificities seem to be determined in a very restricted region. The analysis of site-directed mutants for CmXRS1 that naturally acts at the initial step, i.e. 7-N methylation of xanthosine, revealed that the activity of 3-N methylation needs a histidine residue at corresponding position 161 in the CmXRS1 sequence. We succeeded in producing the mutant enzyme which can catalyze the first and second methylation steps in caffeine biosynthesis.

scholarly journals Growth under high light and elevated temperature affects metabolic responses and accumulation of health-promoting metabolites in kale varieties

2019 ◽  
Author(s):  
Sara Alegre ◽  
Jesús Pascual ◽  
Andrea Trotta ◽  
Peter J. Gollan ◽  
Wei Yang ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
High Irradiance ◽  
High Light ◽  
Leafy Vegetables ◽  
Phenylpropanoid Metabolism ◽  
Crop Species ◽  
Beneficial Effects ◽  
Health Promoting ◽  
Black Magic

AbstractPlants are highly sensitive to changes in the light environment and respond to alternating light conditions by coordinated adjustments in foliar gene expression and metabolism. Here we assessed how long-term growth under high irradiance and elevated temperature, a scenario increasingly associated with the climate change, affects foliar chemical composition of Brassicaceous plants. Transcript profiling of Arabidopsis suggested up-regulation of phenylpropanoid metabolism and down-regulation of processes related to biotic stress resistance and indole glucosinolates (GSL). These observations prompted metabolite profiling of purple (Black Magic) and pale green (Half Tall) varieties of kale, an economically important crop species. Long-term acclimation to high light and elevated temperature resulted in reduced levels of 4-methoxy-indol-3-yl-methyl GSL in both kale varieties. The total levels of aliphatic GSLs increased under these conditions, although the profiles of individual GSL structures showed cultivar-dependent differences. Black Magic became rich in 4-methylsulfinylbutyl GSL and 2-phenylethyl GSL, which have health-promoting effects in human diet. Additionally, the purple pigmentation of Black Magic became intensified due to increased accumulation anthocyanins, especially derivatives of cyanidin. These findings demonstrate that the potentially stressful combination of high light and elevated temperature can have beneficial effects on the accumulation of health-promoting metabolites in leafy vegetables.

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