scholarly journals Effect of Short-Term Cold Treatment on Carbohydrate Metabolism in Potato Leaves

2021 ◽  
Vol 22 (13) ◽  
pp. 7203
Author(s):  
Sławomir Orzechowski ◽  
Dorota Sitnicka ◽  
Agnieszka Grabowska ◽  
Julia Compart ◽  
Joerg Fettke ◽  
...  

Plants are often challenged by an array of unfavorable environmental conditions. During cold exposure, many changes occur that include, for example, the stabilization of cell membranes, alterations in gene expression and enzyme activities, as well as the accumulation of metabolites. In the presented study, the carbohydrate metabolism was analyzed in the very early response of plants to a low temperature (2 °C) in the leaves of 5-week-old potato plants of the Russet Burbank cultivar during the first 12 h of cold treatment (2 h dark and 10 h light). First, some plant stress indicators were examined and it was shown that short-term cold exposure did not significantly affect the relative water content and chlorophyll content (only after 12 h), but caused an increase in malondialdehyde concentration and a decrease in the expression of NDA1, a homolog of the NADH dehydrogenase gene. In addition, it was shown that the content of transitory starch increased transiently in the very early phase of the plant response (3–6 h) to cold treatment, and then its decrease was observed after 12 h. In contrast, soluble sugars such as glucose and fructose were significantly increased only at the end of the light period, where a decrease in sucrose content was observed. The availability of the monosaccharides at constitutively high levels, regardless of the temperature, may delay the response to cold, involving amylolytic starch degradation in chloroplasts. The decrease in starch content, observed in leaves after 12 h of cold exposure, was preceded by a dramatic increase in the transcript levels of the key enzymes of starch degradation initiation, the α-glucan, water dikinase (GWD-EC 2.7.9.4) and the phosphoglucan, water dikinase (PWD-EC 2.7.9.5). The gene expression of both dikinases peaked at 9 h of cold exposure, as analyzed by real-time PCR. Moreover, enhanced activities of the acid invertase as well as of both glucan phosphorylases during exposure to a chilling temperature were observed. However, it was also noticed that during the light phase, there was a general increase in glucan phosphorylase activities for both control and cold-stressed plants irrespective of the temperature. In conclusion, a short-term cold treatment alters the carbohydrate metabolism in the leaves of potato, which leads to an increase in the content of soluble sugars.

BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Ziye Xu ◽  
Wenjing You ◽  
Yanbing Zhou ◽  
Wentao Chen ◽  
Yizhen Wang ◽  
...  

Abstract Background In mammals, cold exposure induces browning of white adipose tissue (WAT) and alters WAT gene expression and lipid metabolism to boost adaptive thermogenesis and maintain body temperature. Understanding the lipidomic and transcriptomic profiles of WAT upon cold exposure provides insights into the adaptive changes associated with this process. Results Here, we applied mass spectrometry and RNA sequencing (RNA-seq) to provide a comprehensive resource for describing the lipidomic or transcriptome profiles in cold-induced inguinal WAT (iWAT). We showed that short-term (3-day) cold exposure induces browning of iWAT, increases energy expenditure, and results in loss of body weight and fat mass. Lipidomic analysis shows that short-term cold exposure leads to dramatic changes of the overall composition of lipid classes WAT. Notably, cold exposure induces significant changes in the acyl-chain composition of triacylglycerols (TAGs), as well as the levels of glycerophospholipids and sphingolipids in iWAT. RNA-seq and qPCR analysis suggests that short-term cold exposure alters the expression of genes and pathways involved in fatty acid elongation, and the synthesis of TAGs, sphingolipids, and glycerophospholipids. Furthermore, the cold-induced lipid dynamics and gene expression pathways in iWAT are contrary to those previously observed in metabolic syndrome, neurodegenerative disorders, and aging, suggesting beneficial effects of cold-induced WAT browning on health and lifespan. Conclusion We described the significant alterations in the composition of glyphospholipids, glycerolipids, and sphingolipids and expression of genes involved in thermogenesis, fatty acid elongation, and fatty acid metabolism during the response of iWAT to short-term cold exposure. We also found that some changes in the levels of specific lipid species happening after cold treatment of iWAT are negatively correlated to metabolic diseases, including obesity and T2D.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Hossein Arefanian ◽  
Irina Al-Khairi ◽  
Nermeen Abu Khalaf ◽  
Preethi Cherian ◽  
Sina Kavalakatt ◽  
...  

Abstract Background Angiopoietin-like proteins (ANGPTL), primarily 3, 4, and 8, play a major role in maintaining energy homeostasis by regulating triglyceride metabolism. This study evaluated the level of ANGPTL3, 4, and 8 in the liver, brown adipose tissue (BAT), and subcutaneous white adipose tissue (SAT) of mice maintained under acute and chronic cold conditions. Methods C57BL/6J mice were exposed to cold temperature (4 °C) for 10 days with food provided ad libitum. Animal tissues were harvested at Day 0 (Control group, n = 5) and Days 1, 3, 5, and 10 (cold treatment groups, n = 10 per group). The expression levels of various genes were measured in the liver, SAT, and BAT. ANGPTL3, 4, and 8 expressions were measured in the liver. ANGPTL4, 8, and genes involved in browning and lipid metabolism [uncoupling protein 1 (UCP1), lipoprotein lipase (LPL), and adipose triglyceride lipase (ATGL)] were measured in SAT and BAT. Western blotting (WB) analysis and immunohistochemistry (IHC) were performed to confirm ANGPTL8 expression in these tissues. Results The expressions of ANGPTL3 and 8 mRNA were significantly reduced in mouse liver tissues after cold treatment (P < 0.05); however, the expression of ANGPTL4 was not significantly altered. In BAT, ANGPTL8 expression was unchanged after cold treatment, whereas ANGPTL4 expression was significantly reduced (P < 0.05). ANGPTL4 levels were also significantly reduced in SAT, whereas ANGPTL8 gene expression exhibited over a 5-fold increase. Similarly, UCP1 gene expression was also significantly increased in SAT. The mRNA levels of LPL and ATGL showed an initial increase followed by a gradual decrease with an increase in the days of cold exposure. ANGPTL8 protein overexpression was further confirmed by WB and IHC. Conclusions This study shows that exposure to acute and chronic cold treatment results in the differential expression of ANGPTL proteins in the liver and adipose tissues (SAT and BAT). The results show a significant reduction in ANGPTL4 in BAT, which is linked to improved thermogenesis in response to acute cold exposure. ANGPTL8 was activated under acute and chronic cold conditions in SAT, suggesting that it is involved in regulating lipolysis and enhancing SAT browning.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 454c-454
Author(s):  
Anil P. Ranwala ◽  
Beth Hardin ◽  
William B. Miller

The energy and carbon needs for early shoot growth in tulips are mainly provided by reserve carbohydrates in bulbs. The cold-treatment of bulbs before greenhouse forcing enhances the breakdown and remobilization of reserve carbohydrates in bulb scales, and is necessary for proper shoot growth and flowering in tulips. Tulip bulbs are known to contain both starch and fructans as reserve carbohydrates. We evaluated several extraction solvents, including ethanol and distilled water, and several extraction temperatures to accurately determine the amounts of different types of non-structural carbohydrates in tulip bulb scales. Extraction with distilled water resulted in excessive solubilization of starch. For example, extraction at 70 °C solubilized more than 80% of starch to glucan polymers. On the other hand, 80% ethanol at 70 °C extracted all soluble sugars including fructans with no apparent solubilization of starch. The changes in non-structural carbohydrates in the outermost bulb scale of tulip (Tulipa gesneriana L. `Frankfurt') during 12 weeks of cooling at 8.8 °C followed by 5 weeks of greenhouse forcing were determined. Starch was the major carbohydrate in bulb scales consisting of ≈70% of the dry weight at the beginning of cold treatment. Starch content per scale decreased slightly during cold treatment, but rapidly after transferring to greenhouse. Sucrose and soluble fructan content per scale increased during cold treatment, then decreased after transferring to greenhouse. Glucose content per scale remained fairly constant during cooling and greenhouse forcing, while fructose content increased in the greenhouse.


Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2277
Author(s):  
Kenji Saito ◽  
Maiko Ito ◽  
Takuya Chiba ◽  
Huijuan Jia ◽  
Hisanori Kato

Many studies have shown the beneficial effects of calorie restriction (CR) on rodents’ aging; however, the molecular mechanism explaining these beneficial effects is still not fully understood. Previously, we conducted transcriptomic analysis on rat liver with short-term and mild-to-moderate CR to elucidate its early response to such diet. Here, we expanded transcriptome analysis to muscle, adipose tissue, intestine, and brain and compared the gene expression profiles of these multiple organs and of our previous dataset. Several altered gene expressions were found, some of which known to be related to CR. Notably, the commonly regulated genes by CR include nicotinamide phosphoribosyltransferase and heat shock protein 90, which are involved in declining the aging process and thus potential therapeutic targets for aging-related diseases. The data obtained here provide information on early response markers and key mediators of the CR-induced delay in aging as well as on age-associated pathological changes in mammals.


Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1670
Author(s):  
Bok-Rye Lee ◽  
Rashed Zaman ◽  
Van Hien La ◽  
Dong-Won Bae ◽  
Tae-Hwan Kim

The leaf senescence process is characterized by the degradation of macromolecules in mature leaves and the remobilization of degradation products via phloem transport. The phytohormone ethylene mediates leaf senescence. This study aimed to investigate the ethephon-induced ethylene effects on starch degradation and sucrose remobilization through their interactive regulation with other hormones. Ethephon (2-chloroethylphosphonic acid) was used as an ethylene-generating agent. Endogenous hormonal status, carbohydrate compounds, starch degradation-related gene expression, sucrose transporter gene expression, and phloem sucrose loading were compared between the ethephon-treated plants and controls. Foliar ethephon spray enhanced the endogenous ethylene concentration and accelerated leaf senescence, as evidenced by reduced chlorophyll content and enhanced expression of the senescence-related gene SAG12. Ethephon-enhanced ethylene prominently enhanced the endogenous abscisic acid (ABA) level. accompanied with upregulation of ABA synthesis gene 9-cis-epoxycarotenoid dioxygenase (NCED3), ABA receptor gene pyrabactin resistance 1 (PYR1), and ABA signaling genes sucrose non-fermenting 1 (Snf1)-related protein kinase 2 (SnRK2), ABA-responsive element binding 2 (AREB2), and basic-helix-loop-helix (bHLH) transcription factor (MYC2).) Ethephon treatment decreased starch content by enhancing expression of the starch degradation-related genes α-amylase 3 (AMY3) and β-amylase 1 (BAM1), resulting in an increase in sucrose content in phloem exudates with enhanced expression of sucrose transporters, SUT1, SUT4, and SWEET11. These results suggest that a synergistic interaction between ethylene and ABA might account for sucrose accumulation, mainly due to starch degradation in mature leaves and sucrose phloem loading in the ethephon-induced senescent leaves.


1991 ◽  
Vol 71 (2) ◽  
pp. 419-425 ◽  
Author(s):  
L. Merlo ◽  
R. Ghisi ◽  
C. Passera ◽  
N. Rascio

Maize plants were grown in nutrient solution with or without 100 mg organic carbon L−1 of humic substances (HS) (MW > 12 000) extracted from a cambisol. To evaluate the effect of HS on leaf carbohydrate metabolism, after 14 d of growth apical and basal segments from the third leaf were collected and analyzed for sugar content and for the activities of enzymes involved in the synthesis and breakdown of starch and sucrose. Leaf starch content decreased in treated plants, whereas the level of soluble sugars increased. The decrease of starch was accompanied by an enhanced activity of amylase, whereas the activity of ADPglucose pyrophosphorylase was not affected. Activities of invertases and sucrose synthase were stimulated by HS treatment in apical tissue, and inhibited in basal one. Activities of enzymes involved in sucrose biosynthesis (sucrose phosphate synthase, cytoplasmic fructose-1,6- bisphosphatase, UDPglucose pyrophosphorylase) were stimulated or inhibited depending on the enzyme and on the tissue examined. Our results show that HS may affect both the level and percent distribution of sugars of maize leaves; these effects seem to be mediated by changes in the activities of enzymes involved in carbohydrate metabolism. Key words: Humic substances, enzymes, carbohydrate metabolism, maize


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.


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