scholarly journals Transcriptomic Analysis of Short-Term Salt Stress Response in Watermelon Seedlings

2020 ◽  
Vol 21 (17) ◽  
pp. 6036
Author(s):  
Qiushuo Song ◽  
Madhumita Joshi ◽  
Vijay Joshi

Watermelon (Citrullus lanatus L.) is a widely popular vegetable fruit crop for human consumption. Soil salinity is among the most critical problems for agricultural production, food security, and sustainability. The transcriptomic and the primary molecular mechanisms that underlie the salt-induced responses in watermelon plants remain uncertain. In this study, the photosynthetic efficiency of photosystem II, free amino acids, and transcriptome profiles of watermelon seedlings exposed to short-term salt stress (300 mM NaCl) were analyzed to identify the genes and pathways associated with response to salt stress. We observed that the maximal photochemical efficiency of photosystem II decreased in salt-stressed plants. Most free amino acids in the leaves of salt-stressed plants increased many folds, while the percent distribution of glutamate and glutamine relative to the amino acid pool decreased. Transcriptome analysis revealed 7622 differentially expressed genes (DEGs) under salt stress, of which 4055 were up-regulated. The GO analysis showed that the molecular function term “transcription factor (TF) activity” was enriched. The assembled transcriptome demonstrated up-regulation of 240 and down-regulation of 194 differentially expressed TFs, of which the members of ERF, WRKY, NAC bHLH, and MYB-related families were over-represented. The functional significance of DEGs associated with endocytosis, amino acid metabolism, nitrogen metabolism, photosynthesis, and hormonal pathways in response to salt stress are discussed. The findings from this study provide novel insights into the salt tolerance mechanism in watermelon.

1991 ◽  
Vol 160 (1) ◽  
pp. 149-165
Author(s):  
J. Henriksson

Protein is not normally an important energy fuel for exercising muscle. In spite of this, there is a significant increase in the rate of amino acid catabolism during exercise. This is secondary to the exercise-induced increase in several metabolic processes, such as hepatic gluconeogenesis and the citric acid cycle, where amino acid carbon is utilized. The suppression of protein synthesis during an exercise bout leaves amino acids available for catabolism. There is some evidence that basal amino acid concentrations in plasma and muscle may be higher in trained than in untrained individuals. In the rat, the concentration of free amino acids is higher in slow-twitch than in fast-twitch muscles. With short-term exercise, the transamination of glutamate by alanine aminotransferase leads to increased levels of alanine in muscle and plasma, and an increased release of alanine from the muscle. At the same time, the muscle and plasma glutamate concentrations are markedly decreased. The plasma glutamine level is elevated with short-term exercise, but changes in muscle glutamine concentration are more variable. With prolonged exercise, there is a depletion of the plasma amino acid pool, which may be explained by an increased consumption in organs other than muscle. With the exception of alanine, we found, however, that the muscle levels of free amino acids are kept stable throughout a 3.5-h exercise period. There is a significant activation of branched-chain amino acid metabolism with prolonged exercise, and the current data indicate that this is more pronounced in endurance-trained subjects than in untrained controls.


1973 ◽  
Vol 28 (7-8) ◽  
pp. 449-451 ◽  
Author(s):  
G. Peter ◽  
H. Angst ◽  
U. Koch

Free and protein-bound amino acids in serum and scales were investigated. In serum the bound amino acids of psoriatics are significantly higher with exception of Pro, Met, Tyr and Phe in contrast to normal subjects. For free amino acids the differences between normal subjects and psoriatics found in serum and scales are not significant. Results are discussed in relation to the single amino acids and the biochemical correlations are outlined which takes the pathological process as a basis.


1989 ◽  
Vol 19 (6) ◽  
pp. 773-782 ◽  
Author(s):  
Michel A. Campagna ◽  
Hank A. Margolis

Black spruce seedlings (Piceamariana Mill.) were exposed to either elevated (1000 ppm) or ambient (340 ppm) atmospheric CO2 levels at different stages of seedling development over a winter greenhouse production cycle. Seedlings germinated in early February and were placed in CO2 chambers for either 3 or 6 weeks during March, April, May, or August. Total seedling biomass increased under high CO2 conditions for the March, April, and May stages of development, but showed no significant response in August. The greater part of the CO2 response occurred during the second 3 weeks of exposure in March and April but during the first 3 weeks of exposure in May. In September, those seedlings exposed to CO2 in April and May had 30 and 14%, respectively, greater biomass than control seedlings, but seedlings from the other stages of development no longer had significant differences remaining from the CO2 treatment. This suggests that it could be very efficient to give a short well-timed CO2 pulse at the beginning of the production cycle in hopes of producing a size difference that is maintained throughout the remainder of the greenhouse production cycle under ambient levels of CO2. Short-term exposure to elevated CO2 also increased the ratio of shoot dry weight to total height for the March, April, and May stages of development. The ratio of total nonstructural carbohydrates to free amino acids was negatively correlated (r2 = 0.98) with the allocation of new growth between shoots and roots as measured by the allocation coefficient, k (milligrams shoot growth per milligrams root growth). As seedlings developed along their seasonal growth cycle, ratios of total nonstructural carbohydrates to free amino acids increased and the values for k decreased. The effect of CO2 enrichment on these two factors is discussed. Monitoring total nonstructural carbohydrate and free amino acid concentrations in foliage could have potential as a method to predict the percentage of carbon allocated to root systems of entire forest stands as well as of individual tree seedlings.


1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman

Using intragastric titration in dogs with gastric fistulas, dose-response studies were carried out with liver extract and with a mixture of amino acids that matched the free amino acids found in liver extract. All solutions were adjusted to pH 7.0 and osmolality to 290 mosmol x kg-1. Doses are expressed as the sum of the concentrations of all free amino acids. At each dose studied (free amino acid concentration: 2.8, 5.6, 11, 23, and 45 mM), acid secretion in response to the free amino acid mixture was not significantly different from that of liver extract. The peak response to both liver extract and the free amino acid mixture occurred with the 23-mM dose and represented about 60% of the maximal response to histamine. The serum concentrations of gastrin after liver extract and the amino acid mixture were not significantly different. It is concluded that in dogs with gastric fistula, gastric acid secretion and release of gastrin were not significantly different in response to liver extract and to a mixture of amino acids that simulated the free amino acid content of liver extract.


1968 ◽  
Vol 96 (3) ◽  
pp. 303-318 ◽  
Author(s):  
P. M.-B. Leung ◽  
Q. R. Rogers ◽  
A. E. Harper

2008 ◽  
Vol 7 (5) ◽  
pp. 421-425 ◽  
Author(s):  
Vivian E. Shih ◽  
Roseann Mandell ◽  
Harvey L. Levy ◽  
John W. Littlefield

2021 ◽  
Vol 233 ◽  
pp. 02040
Author(s):  
Xuting Bai ◽  
Tao Li ◽  
Honglei Zhao ◽  
Xuepeng Li ◽  
Wenhui Zhu ◽  
...  

Protamex was selected to prepare the hydrolysate. E-tongue, free amino acid combined with soluble peptide analysis were used to detect the flavor changes of Aloididae aloidi during enzymolysis. Degree of proteolysis increased with the prolongation of enzymolysis time, and reached the maximum value at 8 hours. The content of soluble peptide of hydrolysate increased firstly and then decreased in the later process. The E-tongue could effectively distinguish the taste difference of hydrolysates at different enzymolysis time, and the hydrolysate presented strong bitterness and astringency during the whole enzymolysis. The total amount of free amino acids in the hydrolysate increased gradually, and some sweet, umami and bitter amino acids increased in varying degrees during the process of enzymolysis.


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