To investigate the protective effect of sesamin against cadmium chloride (CdCl2)-induced cardiotoxicity in rats.Fifty male Wistar rats were randomly assigned to five groups: control group, CdCl2 group, and low-, middle-, and high-dose sesamin groups. The control group was given normal saline. The CdCl2 group and sesamin groups were intraperitoneally injected with CdCl2 (5 mg/kg×2 d), and the low-, middle-, and high-dose sesamin groups were given 20, 40, and 80 mg/kg sesamin, respectively. All treatments lasted for four weeks. ECG was measured by a physiological recorder, and serum myocardial enzyme levels were determined by biochemical assay. The heart was weighed, and heart tissues were used in histopathological examination and determination of malondialdehyde (MDA) level.Compared with the control group, the CdCl2 group showed significantly higher levels of serum CK and CK-MB, an increased heart coefficient, significant ST-segment elevation, and higher level of MDA in myocardial tissue (P < 0.05). Histopathological analysis showed edema of myocardial tissues and cells, myocardial fibers disorder, karyopyknosis, and uneven or deep staining of nuclear chromatin. Different doses of sesamin relieved the myocardial pathological changes induced by CdCl2, and high-dose sesamin was the most effective. The middle- and high-dose sesamin groups showed significantly reduced serum CK and CK-MB levels compared with the CdCl2 group (P < 0.05). The heart coefficient of the high-dose sesamin group (0.19±0.01%) was significantly lower than that of the CdCl2 group (0.21±0.01%) (P < 0.05). Myocardial MDA levels of the three sesamin groups (42.32±4.65, 36.71±5.34, and 33.12±4.62 nmol/mg pro, respectively) were all significantly lower than that of the CdCl2 group (55.87±3.65 nmol/mg pro) (P < 0.05).Sesamin can relieve myocardial injury induced by CdCl2, and one possible mechanism is the enhancement of antioxidant capacity of myocardial tissue.
Nickel (Ni) contaminated soil is a persistent risk to plant growth and production worldwide. Therefore, to explore the Ni toxicity levels in sweetpotato production areas, we investigated the influence of different Ni treatments (0, 7.5, 15, 30, and 60 mg L -1 ) for 15 days on phenotype, Ni uptake, relative water content, gas exchange, photosynthetic pigments, oxidative stress, osmolytes, antioxidants, and enzymes of sweetpotato plants. The results presented that Ni at higher levels (30 and 60 mg L -1 ) substantially reduced growth, biomass, and root morphological traits. The Pearson correlation analysis suggested that Ni toxicity causes oxidative injuries as persistent augmentation of hydrogen peroxide (H 2 O 2 ) and malonaldehyde (MDA) and reduced RWC, gas exchange, and photosynthetic pigment. Furthermore, this study revealed that sweetpotato could tolerate moderate Ni treatment (up to 15 mg L -1 ) by reducing oxidative stress. The results also indicated that the increase in the activities of mentioned osmolytes, antioxidants, and enzymes is not sufficient to overcome the higher Ni toxicity. Based on these results, we suggest using low Ni-contaminated soil for better growth of sweetpotato and also could be used as a phytoremediator in moderate Ni-contaminated soil.
Graphene oxide (GO) nanosheets are promising noble-metal-free catalysts. However, the catalytic activity and selectivity of GO are still very low. Herein, GO is first functionalized via noncovalent interactions by an aspartic acid modified anhydride having COOH groups to form A-GO. A-GO is more conductive and hydrophilic than GO and P-GO synthesized via functionalizing GO by a COOH-free anhydride. Then, we load CdS nanoparticles, which are responsible for absorbing light to produce charge carriers, on A-GO to fabricate a CdS/A-GO photocatalyst without noble metals for the photoreduction of CO2 by H2O. CdS/A-GO exhibits a higher photoreduction efficiency than that of CdS/GO and CdS/P-GO. The main carbon-based photoreduction product of CdS/A-GO is CH3OH, whereas that of CdS/GO and CdS/P-GO is CO. The more conductive and hydrophilic A-GO triggers a more efficient electron transfer, CO2 adsorption, and production of hydrogen atoms from H2O dissociation, thus leading to the higher photoreduction efficiency and product change on CdS/A-GO. Besides, the COOH groups of the aspartic acid modified anhydride supply their hydrogen atoms to promote the conversion from CO2 to CH3OH on CdS/A-GO. Therefore, noncovalently functionalizing GO with different active species can efficiently improve the catalytic performance of GO. This opens a new way to design and construct noble-metal-free catalysts with enhanced activity and selectivity.
The D-type cyclin (CYCD) gene, as the rate-limiting enzyme in the G1 phase of cell cycle, plays a vital role in the process of plant growth and development. Early studies on plant cyclin mostly focused on herbs, such as Arabidopsis thaliana. The sustainable growth ability of woody plants is a unique characteristic in the study of plant cyclin. Here, the promoter of PsnCYCD1;1 was cloned from poplar by PCR and genetically transformed into tobacco. A strong GUS activity was observed in the areas with vigorous cell division, such as stem tips, lateral buds, and young leaves. The PsnCYCD1;1-GFP fusion expression vector was transformed into tobacco, and the green fluorescence signal was observed in the nucleus. Compared with the control plant, the transgenic tobacco showed significant changes in the flower organs, such as enlargement of sepals, petals, and fruits. Furthermore, the stems of transgenic plants were slightly curved at each stem node, the leaves were curled on the adaxial side, and the fruits were seriously aborted after artificial pollination. Microscopic observation showed that the epidermal cells of petals, leaves, and seed coats of transgenic plants became smaller. The transcriptional levels of endogenous genes, such as NtCYCDs, NtSTM, NtKNAT1, and NtASs, were upregulated by PsnCYCD1;1. Therefore, PsnCYCD1;1 gene played an important role in the regulation of flower organ and stem development, providing new understanding for the functional characterization of CYCD gene and new resources for improving the ornamental value of horticultural plants.
Plants generate a range of physiological and molecular responses to sustain their growth and development when suffering heat stress. Avocado is a type of tropical fruit tree with high economic value. Most avocado cultivars delete, wither, or even die when exposed to heat stress for a long time, which seriously restricts the introduction and cultivation of avocados. In this study, samples of a heat-intolerant variety (‘Hass’) were treated under heat stress, and the transcriptomics and metabolomics were analyzed, with the expectation of providing information on the variety improvement and domestication of avocados. The differentially expressed genes identified using transcriptome analysis mainly involved metabolic pathways such as plant hormone signal transduction, plant–pathogen interaction, and protein processing in the endoplasmic reticulum. Combined transcriptome and metabolome analysis indicated that the down-regulation of Hass.g03.10206 and Hass.g03.10205 in heat shock-like proteins may result in the reduced Trehalose and Sinapoyl aldehyde content. Metabolomics analysis results indicated that the decrease in Trehalose and Sinapoyl aldehyde content may be an important factor for heat intolerance. These results provide important clues for understanding the physiological mechanisms of adaptation to heat stress in avocados.
We wanted to identify genes that are controlled by the circadian clock in the prokaryotic cyanobacterium Synechococcus sp. strain PCC 7942. To use luciferase as a reporter to monitor gene expression, bacterial luciferase genes (luxAB) were inserted randomly into the Synechococcus genome by conjugation with Escherichia coli and subsequent homologous recombination. The resulting transformed clones were then screened for bioluminescence using a new developed cooled-CCD camera system. We screened approximately 30,000 transformed Synechococcus colonies and recovered approximately 800 clones whose bioluminescence was bright enough to be easily monitored by the screening apparatus. Unexpectedly, the bioluminescence expression patterns of almost all of these 800 colonies clearly manifested circadian rhythmicity. These rhythms exhibited a range of waveforms and amplitudes, and they also showed a variety of phase relationships. We also found bioluminescence rhythms expressed by cyanobacterial colonies in which the luciferase gene set was coupled to the promoters of several known genes. Together, these results indicate that control of gene expression by circadian clocks may be more widespread than expected thus far. Moreover, our results show that screening organisms in which promoterless luciferase genes have been inserted randomly throughout the genome by homologous recombination provides an extremely sensitive method to explore differential gene expression.
In eukaryotic cells, the role of mitochondria is to generate both ATP and carbon skeletons for biosynthetic purposes. Meanwhile, the mitochondrial genes, in plant, are also involved in the development of anther. The presence of genetic information within mitochondria and nucleus make intracellular cooperation necessary. In this paper, a new RAPD method is used to analyze the expression differences of rice mitochondrial gene with the change of nuclear background. Many different fragments are obtained from hybrids, but not from sterile line or remainder line. According to the results, it is concluded that there are extensive effects of nuclear background on mitochondrial gene expression.
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