Alteration of gene expression in tomato plants (Lycopersicon esculentum) by drought and salt stress

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 385-391 ◽  
Author(s):  
R. D. Chen ◽  
Z. Tabaeizadeh

The effect of drought and NaCl treatments on polypeptide levels in both roots and leaves of tomato (Lycopersicon esculentum) seedlings was analyzed using two-dimensional polyacrylamide gel electrophoresis. In roots, comparison of silver-stained protein patterns showed that during drought treatment two proteins were highly accumulated and after rehydration they returned to the control level. The same changes were also observed under salinity stress. Moreover, salt treatment induced stress-specific proteins. In leaves, the in vivo labelling of intact leaves with 35S-labelled methionine showed that drought stress resulted in progressive changes in the protein pattern. There is de novo synthesis of proteins and repression of preexisting protein synthesis. The time course of appearance of newly synthesized proteins was different during water stress. The changes in proteins were usually reversible after rehydration of the seedlings. Leaves of NaCl-treated plants did not synthesize any salt stress specific polypeptides, but the synthesis of several drought-modulated proteins was affected. It is suggested that the quantitative and qualitative changes in protein synthesis may contribute to stress-resistant or stress-injury mechanisms.Key words: drought stress, Lycopersicon esculentum, protein synthesis, salt stress.

2019 ◽  
Vol 476 (22) ◽  
pp. 3521-3532
Author(s):  
Eric Soubeyrand ◽  
Megan Kelly ◽  
Shea A. Keene ◽  
Ann C. Bernert ◽  
Scott Latimer ◽  
...  

Plants have evolved the ability to derive the benzenoid moiety of the respiratory cofactor and antioxidant, ubiquinone (coenzyme Q), either from the β-oxidative metabolism of p-coumarate or from the peroxidative cleavage of kaempferol. Here, isotopic feeding assays, gene co-expression analysis and reverse genetics identified Arabidopsis 4-COUMARATE-COA LIGASE 8 (4-CL8; At5g38120) as a contributor to the β-oxidation of p-coumarate for ubiquinone biosynthesis. The enzyme is part of the same clade (V) of acyl-activating enzymes than At4g19010, a p-coumarate CoA ligase known to play a central role in the conversion of p-coumarate into 4-hydroxybenzoate. A 4-cl8 T-DNA knockout displayed a 20% decrease in ubiquinone content compared with wild-type plants, while 4-CL8 overexpression boosted ubiquinone content up to 150% of the control level. Similarly, the isotopic enrichment of ubiquinone's ring was decreased by 28% in the 4-cl8 knockout as compared with wild-type controls when Phe-[Ring-13C6] was fed to the plants. This metabolic blockage could be bypassed via the exogenous supply of 4-hydroxybenzoate, the product of p-coumarate β-oxidation. Arabidopsis 4-CL8 displays a canonical peroxisomal targeting sequence type 1, and confocal microscopy experiments using fused fluorescent reporters demonstrated that this enzyme is imported into peroxisomes. Time course feeding assays using Phe-[Ring-13C6] in a series of Arabidopsis single and double knockouts blocked in the β-oxidative metabolism of p-coumarate (4-cl8; at4g19010; at4g19010 × 4-cl8), flavonol biosynthesis (flavanone-3-hydroxylase), or both (at4g19010 × flavanone-3-hydroxylase) indicated that continuous high light treatments (500 µE m−2 s−1; 24 h) markedly stimulated the de novo biosynthesis of ubiquinone independently of kaempferol catabolism.


1972 ◽  
Vol 55 (1) ◽  
pp. 82-92 ◽  
Author(s):  
Joram Piatigorsky ◽  
Henry deF. Webster ◽  
Miriam Wollberg

Previous studies have shown that cells in the 6-day old embryonic chick lens epithelium elongate in tissue culture. In the present study, the time course of elongation during the 1st day of cultivation has been examined histologically. Cultured epithelia were also treated with cycloheximide or colchicine in order to determine if cell elongation depends on new protein synthesis and on the utilization of microtubules, respectively. In the first 5 hr of culture, the mean cell length increased from 11 µ to 21 µ. Subsequently, elongation was slower; the mean cell length was 28 µ after 24 hr in culture. Continuous exposure to cycloheximide did not inhibit the initial doubling of cell length, but did prevent further elongation. By contrast, colchicine inhibited elongation almost immediately. When added after the cell length had doubled, cycloheximide and colchicine each inhibited further elongation; the treated cells remained columnar. Radioautographic and electrophoretic tests showed that protein synthesis was not appreciably affected by colchicine, but was suppressed by cycloheximide. Electron microscopic examination revealed that microtubules oriented along surface membranes were present in epithelia cultured with serum alone and with cycloheximide, but not in those incubated with colchicine. These results indicate that the early stages of cell elongation in the cultured lens epithelium require an initial assembly and organization of preexisting microtubular elements and that continued elongation depends, in addition, on the de novo synthesis of protein, possibly microtubule protein.


Blood ◽  
1990 ◽  
Vol 76 (5) ◽  
pp. 887-891 ◽  
Author(s):  
BP Schick

The relationship of protein synthesis to megakaryocyte maturation has been studied in guinea pigs in vivo. Guinea pigs were injected with a single dose of [35S]methionine. Megakaryocytes and platelets were isolated daily for 4 days, and proteins from both cells were isolated by DEAE-Sephacel chromatography and analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography. All proteins in megakaryocytes corresponding to stained bands on the SDS- PAGE gels were radiolabeled at 3 hours after injection. The greatest loss of radioactivity from the megakaryocytes occurred between 1 and 3 days after injection. Only trace labeling of platelet proteins was seen at 3 hours, representing almost entirely three bands at molecular weights 47,000, 52,000, and 66,000. At 24 hours only about 13% of the maximal labeling was present, but not all proteins were labeled. The maximal labeling was at 3 days. The pattern of labeling of platelets at 3 days was identical to that of megakaryocytes at 3 hours. The protein pattern of nonmegakaryocytic marrow cells was different from that of the platelets and megakaryocytes. Data presented here suggest that most protein synthesis in megakaryocytes is completed at least 24 hours before release of the platelets to the circulation, and suggest some specificity in the proteins that are synthesized at the terminal stages of maturation.


2008 ◽  
Vol 20 (2) ◽  
pp. 105-118 ◽  
Author(s):  
Carlos E.B. de Abreu ◽  
José T. Prisco ◽  
Ana R.C. Nogueira ◽  
Marlos A. Bezerra ◽  
Claudivan F. de Lacerda ◽  
...  

The effects of salt stress on some physiological and biochemical traits were evaluated in dwarf-cashew seedlings at the same developmental stage. Seeds were sown in trays containing vermiculite moistened with distilled water or with NaCl solutions having different electrical conductivities: 0.7, 1.8, 6.0, 9.8, 13.4, 17.4 and 20.6 dS m-1. Salinity delayed and inhibited seedling growth and development, particularly in the shoot. Concentrations of Na+ and Cl-, but not of K+, increased with increasing stress severity. With the exception of proline, concentration of organic solutes was only marginally affected by salt stress. Catalase activity in leaves increased slightly as a result of salt stress, whereas guaiacol peroxidase activity was induced only under low levels of salt. In contrast, activities of guaiacol peroxidase and ascorbate peroxidase increased dramatically in roots. Apparently, roots were better protected against oxidative damage than shoots, as judged from the decrease in lipid peroxidation in root tissues. In leaves, expression of 75 proteins, evaluated by 2D electrophoresis, was altered by salt stress: 35 of them increased their expression and three were apparently de novo synthesized. In roots, 69 proteins were modified by salt stress: 34 proteins increased their expression and two proteins appeared only in stressed seedlings. The changes in protein patterns were caused by the imposed salt stress rather than by a response to the developmental stage. Overall, these responses could play an important role in salt stress acclimation of cashew seedlings.


1993 ◽  
Vol 265 (6) ◽  
pp. R1380-R1386 ◽  
Author(s):  
S. P. Brooks ◽  
K. B. Storey

Changes in de novo protein synthesis and protein phosphorylation were monitored during anoxia and recovery in the red-eared slider Trachemys (= Pseudemys) scripta elegans. Time courses of 35S-radiolabeled methionine incorporation into acid-precipitable material showed an increase up to 5 h postinjection and remained constant after this time. Comparison of the total and acid-precipitable 35S label incorporation into tissues from 20-h control, anoxic, and recovering animals showed differences between these groups: total radioactivity in brain was 2.9-fold lower in recovering turtles, whereas protein-associated radioactivity was 2.4-fold higher in anoxic liver, 2.3-fold lower in recovering skeletal muscle, and 3.7-fold lower in recovering brain tissue. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of radiolabeled proteins showed the existence of a newly synthesized protein band (relative molecular mass = 72 kDa) that was apparent only in 20-h recovering liver and skeletal muscle. Use of 32P labeling to monitor changes in protein phosphorylation patterns during anoxia revealed 1.6-, 1.4-, and 1.5-fold increases in 32P incorporation in anoxic brain, heart, and liver, respectively. Changes in protein phosphorylation were localized to the plasma membrane and cytosolic fractions in brain and to the cytosolic fraction in liver.


1997 ◽  
Vol 273 (4) ◽  
pp. H1894-H1902 ◽  
Author(s):  
Xianzhong Meng ◽  
Lihua Ao ◽  
James M. Brown ◽  
Daniel R. Meldrum ◽  
Brett C. Sheridan ◽  
...  

Lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α independently induce cardioprotection against ischemia in the rat at 24 h after administration, suggesting that endogenously synthesized TNF-α may play a role in LPS-induced protection. The purposes of this study were 1) to delineate the time course of LPS-induced cardiac functional protection against ischemia and its relation with myocardial and circulating TNF-α profile, 2) to examine whether prior protein synthesis inhibition abrogates the protection, and 3) to assess the effects of TNF-α inhibition and neutralization on the protection. Rats were treated with LPS (0.5 mg/kg ip). Cardiac functional resistance to normothermic global ischemia-reperfusion was examined at sequential time points after LPS treatment in isolated hearts by the Langendorff technique. Myocardial and circulating TNF-α was determined by enzyme-linked immunosorbent assay at 1–24 h after LPS treatment. Protection was apparent at 24 h, 3 days, and 7 days but not at 2 or 12 h. Maximal protection at 3 days was abolished by cycloheximide pretreatment (0.5 mg/kg ip 3 h before LPS treatment). Increases in myocardial and circulating TNF-α preceded the acquisition of protection. Dexamethasone pretreatment (4.0 or 8.0 mg/kg ip 30 min before LPS treatment) abolished peak increase in myocardial TNF-α and substantially suppressed circulating TNF-α (54.3 and 85.9% inhibition, respectively) without an influence on the maximal protection. Similarly, maximal protection was not affected by TNF binding protein (40 or 80 μg/kg iv immediately after LPS treatment). The results suggest that LPS-induced cardiac functional protection against ischemia is a delayed and long-lasting protective response that may involve de novo protein synthesis. Although LPS-induced increase in myocardial and circulating TNF-α precedes the delayed protection, it may not be required for the delayed protection.


Blood ◽  
1990 ◽  
Vol 76 (5) ◽  
pp. 887-891 ◽  
Author(s):  
BP Schick

Abstract The relationship of protein synthesis to megakaryocyte maturation has been studied in guinea pigs in vivo. Guinea pigs were injected with a single dose of [35S]methionine. Megakaryocytes and platelets were isolated daily for 4 days, and proteins from both cells were isolated by DEAE-Sephacel chromatography and analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography. All proteins in megakaryocytes corresponding to stained bands on the SDS- PAGE gels were radiolabeled at 3 hours after injection. The greatest loss of radioactivity from the megakaryocytes occurred between 1 and 3 days after injection. Only trace labeling of platelet proteins was seen at 3 hours, representing almost entirely three bands at molecular weights 47,000, 52,000, and 66,000. At 24 hours only about 13% of the maximal labeling was present, but not all proteins were labeled. The maximal labeling was at 3 days. The pattern of labeling of platelets at 3 days was identical to that of megakaryocytes at 3 hours. The protein pattern of nonmegakaryocytic marrow cells was different from that of the platelets and megakaryocytes. Data presented here suggest that most protein synthesis in megakaryocytes is completed at least 24 hours before release of the platelets to the circulation, and suggest some specificity in the proteins that are synthesized at the terminal stages of maturation.


1988 ◽  
Vol 255 (1) ◽  
pp. F15-F21 ◽  
Author(s):  
K. I. Wu ◽  
R. A. Bacon ◽  
H. A. Al-Mahrouq ◽  
S. A. Kempson

Administration of nicotinamide to rats produces specific dose-dependent inhibition of Na+-dependent phosphate transport across the renal brush-border membrane (BBM) and an increase in urinary excretion of phosphate. The intracellular mechanism of action of nicotinamide is not well established. As a step in this direction, the present studies determined whether nicotinamide was a rapid- or slow-acting regulator of the BBM phosphate transport system. Nicotinamide (0.5 g/kg) inhibited Na+-dependent BBM phosphate transport under conditions when de novo protein synthesis was inhibited by cycloheximide (1.0 mg/kg). Furthermore, the degree of inhibition was not different from that achieved by nicotinamide alone, suggesting that the action of nicotinamide does not require de novo protein synthesis. Studies on the time course of the onset of nicotinamide action revealed inhibition of BBM phosphate transport within 1 h after injection of nicotinamide, even in rats pretreated with cycloheximide. The rapid response to nicotinamide and its independence of de novo protein synthesis characterize nicotinamide as a rapid-acting regulator of the Na+-dependent phosphate transport system in renal BBM.


1991 ◽  
Vol 275 (2) ◽  
pp. 313-319 ◽  
Author(s):  
W T Wong ◽  
S C Frost ◽  
H S Nick

We demonstrate that annexin I/lipocortin I (lipo I) gene expression is regulated by dexamethasone (DEX) in mouse 3T3-L1 fibroblasts and LA-4 lung epithelial cells. We have characterized this induction further in 3T3-L1 fibroblasts. At 24 h after addition of DEX, the levels of lipo I mRNA and protein increased 5-fold and 1.5-fold respectively. Time-course experiments revealed that the induction was delayed by 2-4 h after DEX addition. Half-maximal induction of both lipo I mRNA and protein was achieved with 10 nM-DEX. Both actinomycin D and cycloheximide blocked the DEX effect on lipo I mRNA expression. These results indicate that the induction of lipo I by DEX has a transcriptional component and requires protein synthesis de novo.


2011 ◽  
Vol 6 (1) ◽  
pp. 39
Author(s):  

Background:Since the first reported use of percutaneous transluminal coronary angioplasty, advances in the interventional cardiology arena have been fast paced. Developers and clinicians are adapting from the learning curve awarded by the time-course of drug-eluting stent (DES) evolution. BioMime™ sirolimus-eluting stent (SES) is a step towards biomimicry. The stent is built on a strut of ultra-low thickness (65μm), a cobalt–chromium platform using an intelligent hybrid of closed and open cells allowing for morphology-mediated expansion. It employs a well-known antiproliferative – sirolimus – that elutes from a known biodegradable copolymer formulation within 30 days. The resultant stent demonstrates almost 100% endothelialisation at 30 days in preclinical models.Methods:The meriT-1 was a prospective, single-arm, single-centre trial to evaluate the safety and efficacy of BioMime SES in 30 patients with a single de novo lesion in native coronary arteries. The primary safety and efficacy end-points were major adverse cardiac events (MACE) at 30 days and in-stent late lumen loss at eight months, as measured using quantitative coronary angiographic (QCA) method. Secondary safety and efficacy end-points included MACE at one and two years and angiographic binary restenosis at eight-month angiographic follow-up. Other end-points included the occurrence of stent thrombosis at acute, subacute, late and very late periods and the percentage of diameter stenosis by QCA.Results:No MACE were observed and the median in-stent late luminal loss in 20 (67%) subjects studied by QCA was 0.15mm, with 0% binary restenosis at eight-month follow-up. No stent thrombosis was observed up to one-year follow-up.Conclusions:In comparison to currently available DES, BioMime SES appears to have a considerable scientific basis for prevention of neointimal proliferation, restenosis and associated clinical events.


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