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 ◽  
...  
2011 ◽  
Vol 38 (2) ◽  
pp. 139 ◽  
Author(s):  
Petronia Carillo ◽  
Danila Parisi ◽  
Pasqualina Woodrow ◽  
Giovanni Pontecorvo ◽  
Giuseppina Massaro ◽  
...  

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.


Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Guichun Wu ◽  
Yuqiang Zhang ◽  
Bo Wang ◽  
Kaihuai Li ◽  
Yuanlai Lou ◽  
...  

Abstract Background Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial leaf blight, a devastating rice disease. The Xoo-rice interaction, wherein wide ranging host- and pathogen-derived proteins and genes wage molecular arms race, is a research hotspot. Hence, the identification of novel rice-induced Xoo virulence factors and characterization of their roles affecting rice global gene expression profiles will provide an integrated and better understanding of Xoo-rice interactions from the molecular perspective. Results Using comparative proteomics and an in vitro interaction system, we revealed that 5 protein spots from Xoo exhibited significantly different expression patterns (|fold change| > 1.5) at 3, 6, 12 h after susceptible rice leaf extract (RLX) treatment. MALDI-TOF MS analysis and pathogenicity tests showed that 4 host-induced proteins, including phosphohexose mutase, inositol monophosphatase, arginase and septum site-determining protein, affected Xoo virulence. Among them, mutants of two host-induced carbohydrate metabolism enzyme-encoding genes, ΔxanA and Δimp, elicited enhanced defense responses and nearly abolished Xoo virulence in rice. To decipher rice differentially expressed genes (DEGs) associated with xanA and imp, transcriptomic responses of ΔxanA-treated and Δimp-treated susceptible rice were compared to those in rice treated with PXO99A at 1 and 3 dpi. A total of 1521 and 227 DEGs were identified for PXO99A vs Δimp at 1 and 3 dpi, while for PXO99A vs ΔxanA, there were 131 and 106 DEGs, respectively. GO, KEGG and MapMan analyses revealed that the DEGs for PXO99A vs Δimp were mainly involved in photosynthesis, signal transduction, transcription, oxidation-reduction, hydrogen peroxide catabolism, ion transport, phenylpropanoid biosynthesis and metabolism of carbohydrates, lipids, amino acids, secondary metabolites, hormones, and nucleotides, while the DEGs from PXO99A vs ΔxanA were predominantly associated with photosynthesis, signal transduction, oxidation-reduction, phenylpropanoid biosynthesis, cytochrome P450 and metabolism of carbohydrates, lipids, amino acids, secondary metabolites and hormones. Although most pathways were associated with both the Δimp and ΔxanA treatments, the underlying genes were not the same. Conclusion Our study identified two novel host-induced virulence factors XanA and Imp in Xoo, and revealed their roles in global gene expression in susceptible rice. These results provide valuable insights into the molecular mechanisms of pathogen infection strategies and plant immunity.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yash Sondhi ◽  
Emily A. Ellis ◽  
Seth M. Bybee ◽  
Jamie C. Theobald ◽  
Akito Y. Kawahara

AbstractOpsins, combined with a chromophore, are the primary light-sensing molecules in animals and are crucial for color vision. Throughout animal evolution, duplications and losses of opsin proteins are common, but it is unclear what is driving these gains and losses. Light availability is implicated, and dim environments are often associated with low opsin diversity and loss. Correlations between high opsin diversity and bright environments, however, are tenuous. To test if increased light availability is associated with opsin diversification, we examined diel niche and identified opsins using transcriptomes and genomes of 175 butterflies and moths (Lepidoptera). We found 14 independent opsin duplications associated with bright environments. Estimating their rates of evolution revealed that opsins from diurnal taxa evolve faster—at least 13 amino acids were identified with higher dN/dS rates, with a subset close enough to the chromophore to tune the opsin. These results demonstrate that high light availability increases opsin diversity and evolution rate in Lepidoptera.


1976 ◽  
Vol 3 (3) ◽  
pp. 389 ◽  
Author(s):  
IF Wardlaw ◽  
C Marshall

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.


1959 ◽  
Vol 18 (4) ◽  
pp. 395-408 ◽  
Author(s):  
K. L. MANCHESTER ◽  
P. J. RANDLE ◽  
F. G. YOUNG

SUMMARY 1. The effect of hypophysectomy, or of adrenalectomy, and injection of pituitary growth hormone (GH) or of cortisol, on the uptake of glucose and the incorporation of glycine into protein by isolated rat diaphragm, and the effect of the addition of insulin in vitro on these processes, has been studied. 2. Both hypophysectomy and adrenalectomy raised the uptake of glucose by isolated diaphragm, while treatment of the intact or of the hypophysectomized rat with GH, or of the intact or of the adrenalectomized rat with cortisol, depressed it. Although hypophysectomy and adrenalectomy did not influence the additional glucose uptake induced by 200 mu./ml. of insulin in vitro, both these operations enhanced the effect of 0·1–1·0 mu./ml. of insulin on glucose uptake by diaphragm in vitro. Treatment of the rat with GH or cortisol diminished the rise in glucose uptake of diaphragm induced by 0·1–1·0 mu./ml. insulin. 3. Hypophysectomy depressed, and administration of GH to the intact or hypophysectomized rat raised, the incorporation of glycine into protein of the isolated diaphragm, but neither of these operations altered the magnitude of the stimulation of incorporation induced by 1·0 mu./ml. insulin. 4. Adrenalectomy raised, and administration of cortisol to the intact or adrenalectomized rat depressed, the incorporation of glycine into protein of the isolated diaphragm; adrenalectomy enhanced, the injection of cortisol diminished, the effect of 1·0 mu./ml. insulin on these processes. 5. The possibility that GH directs insulin towards the stimulation of protein synthesis, in part by restraining the action of insulin on carbohydrate metabolism, is discussed.


1979 ◽  
Vol 184 (1) ◽  
pp. 97-106 ◽  
Author(s):  
David L. Topping ◽  
Dallas G. Clark ◽  
Gerald B. Storer ◽  
Rodney P. Trimble ◽  
Richard J. Illman

1. Livers from fed rats were perfused in situ with whole rat blood containing glucose labelled uniformly with 14C and specifically with 3H at positions 2, 3 or 6. 2. When ethanol was infused at a concentration of 24μmol/ml of blood the rate of utilization was 2.8μmol/min per g of liver. 3. Ethanol infusion raised perfusate glucose concentrations and caused a 2.5-fold increase in hepatic glucose output. 4. Final blood lactate concentrations were decreased in ethanol-infused livers, but the mean uptake of lactate from erythrocyte glycolysis was unaffected. 5. Production of ketone bodies (3‐hydroxybutyrate+3‐oxobutyrate) and the ratio [3‐hydroxybutyrate]/[3‐oxobutyrate] were raised by ethanol. 6. Formation of 3H2O from specifically 3H-labelled glucoses increased in the order [6-3H]<[3-3H]<[2-3H]. Production of 3H2O from [2-3H]glucose was significantly greater than that from [3-3H]glucose in both control and ethanol-infused livers. Ethanol significantly decreased 3H2O formation from all [3H]glucoses. 7. Liver glycogen content was unaffected by ethanol infusion. 8. Production of very-low-density lipoprotein triacylglycerols was inhibited by ethanol and there was a small increase in liver triacylglycerols. Very-low-density-lipoprotein secretion was negatively correlated with the ratio [3‐hydroxybutyrate]/[3‐oxobutyrate]. Perfusate fatty acid concentrations and molar composition were unaffected by perfusion with ethanol. 9. Ethanol decreased the incorporation of [U-14C]glucose into fatty acids and cholesterol. 10. The concentration of total plasma amino acids was unchanged by ethanol, but the concentrations of alanine and glycine were decreased and ([glutamate]+[glutamine]) was raised. 11. It is proposed that the observed effects of ethanol on carbohydrate metabolism are due to an increased conversion of lactate into glucose, possibly by inhibition of pyruvate dehydrogenase. The increase in gluconeogenesis is accompanied by diminished substrate cycling at glucose–glucose 6-phosphate and at fructose 6-phosphate–fructose 1,6-bisphosphate.


2005 ◽  
Vol 52 (2) ◽  
pp. 527-534 ◽  
Author(s):  
Wiesław Truszkiewicz ◽  
Andrzej Paszkowski

The structural properties of photorespiratory serine:glyoxylate aminotransferases (SGAT, EC 2.6.1.45) from maize (Zea mays L.) and wheat (Triticum aestivum L.) leaves were examined. By means of molecular sieving on Zorbax SE-250 column and filtration through centrifugal filters it was shown that dimers of wheat enzyme (molecular mass of about 90 kDa) dissociate into component monomers (molecular mass of about 45 kDa) upon decrease in pH value (from 9.1 or 7.0 to 6.5). At pH 9.1 a 50-fold decrease of ionic strength elicited a similar effect. Under the same conditions homodimers of the maize enzyme (molecular mass similar to that of the wheat enzyme) remained stable. Immunoblot analysis with polyclonal antiserum against wheat seedling SGAT on leaf homogenates or highly purified preparations of both enzymes showed that the immunogenic portions of the wheat enzyme are divergent from those of the maize enzyme. The sequence of 136 amino acids of the maize enzyme and 78 amino acids of the wheat enzyme was established by tandem mass spectrometry with time of flight analyzer. The two enzymes likely share similarity in tertiary and quaternary structures as well as high level of hydrophobicity on their molecular surfaces. They likely differ in the mechanism of transport from the site of biosynthesis to peroxisomes as well as in some aspects of secondary structure.


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