Comparative analysis of the plastid conversion, photochemical activity and chlorophyll degradation in developing embryos of green-seeded and yellow-seeded pea (Pisum sativum) cultivars

2020 ◽  
Vol 47 (5) ◽  
pp. 409 ◽  
Author(s):  
Galina Smolikova ◽  
Olga Shiroglazova ◽  
Galina Vinogradova ◽  
Irina Leppyanen ◽  
Ekaterina Dinastiya ◽  
...  

Developing seeds of some higher plants are photosynthetically active and contain chlorophylls (Chl), which are typically destroyed at the late stages of seed maturation. However, in some crop plant cultivars, degradation of embryonic Chl remains incomplete, and mature seeds preserve green colour, as it is known for green-seeded cultivars of pea (Pisum sativum L.). The residual Chl compromise seed quality and represent a severe challenge for farmers. Hence, comprehensive understanding of the molecular mechanisms, underlying incomplete Chl degradation is required for maintaining sustainable agriculture. Therefore, here we address dynamics of plastid conversion and photochemical activity alterations, accompanying degradation of Chl in embryos of yellow- and green-seeded cultivars Frisson and Rondo respectively. The yellow-seeded cultivar demonstrated higher rate of Chl degradation at later maturation stage, accompanied with termination of photochemical activity, seed dehydration and conversion of green plastids into amyloplasts. In agreement with this, expression of genes encoding enzymes of Chl degradation was lower in the green seeded cultivar, with the major differences in the levels of Chl b reductase (NYC1) and pheophytinase (PPH) transcripts. Thus, the difference between yellow and green seeds can be attributed to incomplete Chl degradation in the latter at the end of maturation period.

2012 ◽  
Vol 4 (2) ◽  
pp. 42-44
Author(s):  
Grace Moscoso-Solorzano ◽  
Gianna Mastroianni-Kirsztajn

Cyclophilin A (CypA) belongs to the peptidyl-prolil isomerase (PPlase) family of proteins and it is also known as the cellular receptor for cyclosporine A (CsA). CsA binds to CypA and inhibits the PPIase activity, but the CypA-CsA complex also binds to calcineurin that promotes the expression of genes encoding cytokines and other proteins required for immune response. In addition, the polymorphism variation of CypA promoter seems to have an influence on the expression of CypA in in vitro studies. CypA was also implicated in inflammatory processes (such as, among others, those observed in rheumatoid arthritis, atherosclerotic disease, nephrotoxicity) and it can be secreted by cells in response to inflammatory stimuli. CypA can also have a role in the molecular mechanisms by which CsA induces nephroxicity but these remain poorly understood. Recent studies suggest that CsA inhibition of CypA PPlase activity is a possible mechanism of this drug toxicity. In addition, CypA overexpression could be protective against CsA nephrotoxicity. Finally, the putative common mechanism by which CypA could be involved in CsA nephrotoxicity and tissue injury is related to its proinflammatory effects in cells.


2016 ◽  
Vol 56 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Julika Lietzow ◽  
Janine Golchert ◽  
Georg Homuth ◽  
Uwe Völker ◽  
Wenke Jonas ◽  
...  

The endogenous thyroid hormone (TH) metabolite 3,5-diiodo-l-thyronine (3,5-T2) acts as a metabolically active substance affecting whole-body energy metabolism and hepatic lipid handling in a desirable manner. Considering possible adverse effects regarding thyromimetic action of 3,5-T2 treatment in rodents, the current literature remains largely controversial. To obtain further insights into molecular mechanisms and to identify novel target genes of 3,5-T2 in liver, we performed a microarray-based liver tissue transcriptome analysis of male lean and diet-induced obese euthyroid mice treated for 4 weeks with a dose of 2.5 µg/g bw 3,5-T2. Our results revealed that 3,5-T2 modulates the expression of genes encoding Phase I and Phase II enzymes as well as Phase III transporters, which play central roles in metabolism and detoxification of xenobiotics. Additionally, 3,5-T2 changes the expression of TH responsive genes, suggesting a thyromimetic action of 3,5-T2 in mouse liver. Interestingly, 3,5-T2 in obese but not in lean mice influences the expression of genes relevant for cholesterol and steroid biosynthesis, suggesting a novel role of 3,5-T2 in steroid metabolism of obese mice. We concluded that treatment with 3,5-T2 in lean and diet-induced obese male mice alters the expression of genes encoding hepatic xenobiotic-metabolizing enzymes that play a substantial role in catabolism and inactivation of xenobiotics and TH and are also involved in hepatic steroid and lipid metabolism. The administration of this high dose of 3,5-T2 might exert adverse hepatic effects. Accordingly, the conceivable use of 3,5-T2 as pharmacological hypolipidemic agent should be considered with caution.


2020 ◽  
Vol 64 (12) ◽  
Author(s):  
M. Biagi ◽  
D. Lamm ◽  
K. Meyer ◽  
A. Vialichka ◽  
M. Jurkovic ◽  
...  

ABSTRACT The intrinsic L1 metallo- and L2 serine-β-lactamases in Stenotrophomonas maltophilia make it naturally multidrug resistant and difficult to treat. There is a need to identify novel treatment strategies for this pathogen, especially against isolates resistant to first-line agents. Aztreonam in combination with avibactam has demonstrated potential, although data on other aztreonam–β-lactamase inhibitor (BLI) combinations are lacking. Additionally, molecular mechanisms for reduced susceptibility to these combinations have not been explored. The objectives of this study were to evaluate and compare the in vitro activities and to understand the mechanisms of resistance to aztreonam in combination with avibactam, clavulanate, relebactam, and vaborbactam against S. maltophilia. A panel of 47 clinical S. maltophilia strains nonsusceptible to levofloxacin and/or trimethoprim-sulfamethoxazole were tested against each aztreonam-BLI combination via broth microdilution, and 6 isolates were then evaluated in time-kill analyses. Three isolates with various aztreonam-BLI MICs were subjected to whole-genome sequencing and quantitative reverse transcriptase PCR. Avibactam restored aztreonam susceptibility in 98% of aztreonam-resistant isolates, compared to 61, 71, and 15% with clavulanate, relebactam, and vaborbactam, respectively. The addition of avibactam to aztreonam resulted in a ≥2-log10-CFU/ml decrease at 24 h versus aztreonam alone against 5/6 isolates compared to 1/6 with clavulanate, 4/6 with relebactam, and 2/6 with vaborbactam. Molecular analyses revealed that decreased susceptibility to aztreonam-avibactam was associated with increased expression of genes encoding L1 and L2, as well as the efflux pump (smeABC). Aztreonam-avibactam is the most promising BLI-combination against multidrug-resistant S. maltophilia. Decreased susceptibility may be due to the combination of overexpressed β-lactamases and efflux pumps. Further studies evaluating this combination against S. maltophilia are warranted.


2021 ◽  
Vol 7 (8) ◽  
pp. 612
Author(s):  
Pao-Yu Chen ◽  
Yu-Chung Chuang ◽  
Un-In Wu ◽  
Hsin-Yun Sun ◽  
Jann-Tay Wang ◽  
...  

Objectives: Azole-resistant Candida tropicalis has emerged in Asia in the context of its trailing nature, defined by residual growth above minimum inhibitory concentrations (MICs). However, limited investigations in C. tropicalis have focused on the difference of genotypes and molecular mechanisms between these two traits. Methods: Sixty-four non-duplicated C. tropicalis bloodstream isolates collected in 2017 were evaluated for azole MICs by the EUCAST E.def 7.3.1 method, diploid sequence type (DST) by multilocus sequencing typing, and sequences and expression levels of genes encoding ERG11, its transcription factor, UPC2, and efflux pumps (CDR1, CDR2 and MDR1). Results: Isavuconazole showed the highest in vitro activity and trailing against C. tropicalis, followed by voriconazole and fluconazole (geometric mean [GM] MIC, 0.008, 0.090, 1.163 mg/L, respectively; trailing GM, 27.4%, 20.8% and 19.5%, respectively; both overall p < 0.001). Fourteen (21.9%) isolates were non-WT to fluconazole/voriconazole, 12 of which were non-WT to isavuconazole and clustered in clonal complex (CC) 3. Twenty-five (39.1%) isolates were high trailing WT, including all CC2 isolates (44.0%) (containing DST140 and DST98). All azole non-WT isolates carried the ERG11 mutations A395T/W and/or C461T/Y, and most carried the UPC2 mutation T503C/Y. These mutations were not identified in low and high trailing WT isolates. Azole non-WT and high trailing WT isolates exhibited the highest expression levels of ERG11 and MDR1, 3.91- and 2.30-fold, respectively (both overall p < 0.01). Conclusions: Azole resistance and trailing are phenotypically and genotypically different in C. tropicalis. Interference with azole binding and MDR1 up-regulation confer azole resistance and trailing, respectively.


2022 ◽  
Vol 12 ◽  
Author(s):  
Xianjun Feng ◽  
Jiajun Ma ◽  
Zhiqian Liu ◽  
Xuan Li ◽  
Yinghua Wu ◽  
...  

Glucosinolates (GSLs) are important secondary metabolites that play important defensive roles in cruciferous plants. Chinese flowering cabbage, one of the most common vegetable crops, is rich in GSLs and thus has the potential to reduce the risk of cancer in humans. Many genes that are involved in GSL biosynthesis and metabolism have been identified in the model plant Arabidopsis thaliana; however, few studies investigated the genes related to GSL biosynthesis and metabolism in Chinese flowering cabbage. In the present study, the GSL composition and content in three different organs of Chinese flowering cabbage (leaf, stalk, and flower bud) were determined. Our results showed that the total GSL content in flower buds was significantly higher than in stalks and leaves, and aliphatic GSLs were the most abundant GSL type. To understand the molecular mechanisms underlying the variations of GSL content, we analyzed the expression of genes encoding enzymes involved in GSL biosynthesis and transport in different tissues of Chinese flowering cabbage using RNA sequencing; the expression levels of most genes were found to be consistent with the pattern of total GSL content. Correlation and consistency analysis of differentially expressed genes from different organs with the GSL content revealed that seven genes (Bra029966, Bra012640, Bra016787, Bra011761, Bra006830, Bra011759, and Bra029248) were positively correlated with GSL content. These findings provide a molecular basis for further elucidating GSL biosynthesis and transport in Chinese flowering cabbage.


2018 ◽  
Author(s):  
Dongping Zhang ◽  
Minyan Zhang ◽  
Yong Zhou ◽  
Yuzhu Wang ◽  
Hongyingxue Chen ◽  
...  

The rice genome contains a single Gα (RGA1) and Gβ (RGB1) and five Gγ subunits. Recent genetic studies have shown that DEP1/qPE9-1, an atypical putative Gγ protein, is responsible for dense and erect panicles, but the biochemical and molecular mechanisms underlying control of grain size are not well understood. Here, we report that plants carrying qPE9-1 have more endosperm cells per grain than plants contain the qpe9-1 allele. The qPE9-1 line has a higher rate and longer period of starch accumulation than the qpe9-1 line. Additionally, the expression of several key genes encoding enzymes catalyzing sucrose metabolism and starch biosynthesis is higher in the qPE9-1 line than in the qpe9-1 line, especially from the mid to late grain-filling stage. Grains of the qPE9-1 line also have higher contents of two phytohormones, ABA and IAA. Exogenous application of ABA or IAA enhanced starch accumulation and the expression of genes encoding grain-filling-related enzymes in the grains of qPE9-1, whereas only IAA produced these effects in qpe9-1. Based on these results, we conclude that qPE9-1 promotes endosperm cell proliferation and positively regulates starch accumulation largely through ABA and IAA, which enhance the expression of genes encoding starch biosynthesis during the late grain-filling stage.


2010 ◽  
Vol 299 (3) ◽  
pp. H752-H762 ◽  
Author(s):  
Christophe Depre ◽  
Ji Yeon Park ◽  
You-Tang Shen ◽  
Xin Zhao ◽  
Hongyu Qiu ◽  
...  

A major difference between experimental ischemic preconditioning (IPC), induced by brief ischemic episodes, and the clinical situation is that patients generally have repetitive episodes of ischemia. We used a swine model to examine differences in genes regulated by classical second-window IPC (SWOP) [two 10-min episodes of coronary artery occlusion (CAO) followed by 24 h reperfusion] compared with repetitive CAO/reperfusion (RCO), i.e., two 10-min CAO 12 h apart, and to repetitive coronary stenosis (RCS), six episodes of 90 min coronary stenosis 12 h apart ( n = 5/group). All three models reduced infarct size by 60–85%, which was mediated by nitric oxide in SWOP but not in the other two models. We employed microarray analyses to discover additional molecular pathways intrinsic to models of repetitive ischemia and different from classical SWOP. There was an 85% homology in gene response between the RCO and RCS models, whereas SWOP was qualitatively different. Both RCO and RCS, but not SWOP, showed downregulation of genes encoding proteins involved in oxidative metabolism and upregulation of genes involved in protein synthesis, unfolded protein response, autophagy, heat shock response, protein secretion, and an activation of the NF-κB signaling pathway. Therefore, the regulated genes mediating IPC with repetitive ischemia differ radically from SWOP both quantitatively and qualitatively, showing that a repetitive pattern of ischemia, rather than the difference between no-flow vs. low-flow ischemia, dictates the genomic response of the heart. These findings illustrate new cardioprotective mechanisms developed by repetitive IPC, which are potentially more relevant to patients with chronic ischemic heart disease, who are subjected to repetitive episodes of ischemia.


2007 ◽  
Vol 66 (1) ◽  
pp. 42-51 ◽  
Author(s):  
J. Tyson ◽  
J. C. Mathers

The DNA in all cells of the human body is subject to damage continuously from exogenous agents, internal cellular processes and spontaneous decomposition. Failure to repair such damage is fundamental to the development of many diseases and to ageing. Fortunately, the vast majority of DNA damage is detected and repaired by one of five complementary DNA repair systems. However, recent studies have shown that even in healthy individuals there is a wide inter-individual variation in DNA repair capacity. Part of this variation can be accounted for by polymorphisms in the genes encoding DNA repair proteins. However, it is probable that environmental factors, including dietary exposure as well as diet–gene interactions, are also responsible for much of the difference in repair capacity between individuals. Whilst there is some evidence from human studies that generalised malnutrition or low intakes of specific nutrients may affect DNA repair, as yet there is limited understanding of the molecular mechanisms through which nutrients can modulate this key cellular process.


Rice ◽  
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Dongping Zhang ◽  
Minyan Zhang ◽  
Yong Zhou ◽  
Yuzhu Wang ◽  
Jinyu Shen ◽  
...  

AbstractHeterotrimeric G protein-mediated signal transduction is one of the most important and highly conserved signaling pathways in eukaryotes, which involves in the regulation of many important biological processes. As compared with those in mammals and Arabidopsis thaliana, the functions of rice heterotrimeric G protein and their molecular mechanisms are largely unknown. The rice genome contains a single Gα (RGA1) and Gβ (RGB1), and five Gγ (RGG1, RGG2, GS3, DEP1/qPE9–1, and GGC2) subunits. Recent genetic studies have shown that DEP1/qPE9–1, an atypical putative Gγ protein, is responsible for the grain size as well as the dense and erect panicles, but the biochemical and molecular mechanisms underlying the control of grain size are not well understood. Here, we report that rice plants carrying DEP1/qPE9–1 have more endosperm cells per grain than plants contain the dep1/qpe9–1 allele. The DEP1/qPE9–1 line has a higher rate and more prolonged period of starch accumulation than the dep1/qpe9–1 line. Additionally, the expression of several essential genes encoding enzymes catalyzing sucrose metabolism and starch biosynthesis is higher in the DEP1/qPE9–1 line than in the dep1/qpe9–1 line, especially from the mid to late grain-filling stage. Grains of the DEP1/qPE9–1 line also have higher contents of three phytohormones, ABA, auxin and cytokinin. Exogenous application of auxin or cytokinin enhanced the starch accumulation and the expression of genes encoding grain-filling-related enzymes in the grains of dep1/qpe9–1, whereas ABA produced no effects. Based on these results, we conclude that DEP1/qPE9–1 positively regulates starch accumulation primarily through auxin and cytokinin, which enhance the expression of genes encoding starch biosynthesis during the mid to late grain-filling stage, resulting in increased duration of the grain-filling process.


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