Genome-wide identification of the GRF family in sweet orange (Citrus sinensis) and functional analysis of the CsGRF04 in response to multiple abiotic stresses.

BACKGROUND: Citrus is one of the most valuable fruits worldwide and an economic pillar industry in southern China. Nevertheless, it frequently suffers from undesirable environmental stresses during the growth cycle, which severely restricts the growth, development and yield of citrus. In plants, the growth-regulating factor (GRF) family of transcription factors (TF) is extensively distributed and plays an vital part in plant growth and development, hormone response, as well as stress adaptation. However, the systematic identification and functional analysis of GRF TFs in citrus have not been reported. RESULTS: Here, a genome-wide identification of GRF TFs was performed in Citrus sinensis, 9 members of CsGRFs were systematically identified and discovered to be scattered throughout 5 chromosomes. Subsequently, physical and chemical properties, phylogenetic relationships, structural characteristics, gene duplication events, collinearity and cis-elements of promoter were elaborately analyzed. In particular, the expression patterns of the CsGRF genes in response to multiple phytohormone and abiotic stress treatments were investigated. Predicated on this result, CsGRF04, which exhibited the most differential expression pattern under multiple phytohormone and abiotic stress treatments was screened out. Virus-induced gene silencing (VIGS) technology was utilized to obtain gene silenced plants for CsGRF04 successfully. After the three stress treatments of high salinity, low temperature and drought, the CsGRF04-VIGS lines showed significantly reduced resistance to high salinity and low temperature stresses, but extremely increased resistance to drought stress. CONCLUSIONS: Taken together, our findings systematically analyzed the genomic characterization of GRF family in Citrus sinensis, and excavated a CsGRF04 with potential functions under multiple abiotic stresses. Our study lay a foundation for further study on the function of CsGRFs in abiotic stress and hormone signaling response.

Effect of Walnut Meal Peptides on Hyperlipidemia and Hepatic Lipid Metabolism in Rats Fed a High-Fat Diet.

As a natural active substance that can effectively improve blood lipid balance in the body, hypolipidemic active peptides have attracted the attention of scholars. In this study, the effect of walnut meal peptides (WMP) on lipid metabolism was investigated in rats fed a high-fat diet (HFD). The experimental results show that feeding walnut meal peptides counteracted the high-fat diet-induced increase in body, liver and epididymal fat weight, and reduce the serum concentrations of total cholesterol, triglycerides, and LDL-cholesterol and hepatic cholesterol and triglyceride content. Walnut meal peptides also resulted in increased HDL-cholesterol while reducing the atherosclerosis index (AI). Additionally, the stained pathological sections of the liver showed that the walnut meal peptides reduced hepatic steatosis and damage caused by HFD. Furthermore, walnut meal peptide supplementation was associated with normalization of elevated apolipoprotein (Apo)-B and reduced Apo-A1 induced by the high-fat diet and with favorable changes in the expression of genes related to lipid metabolism (LCAT, CYP7A1, HMGR, FAS). The results indicate that walnut meal peptides can effectively prevent the harmful effects of a high-fat diet on body weight, lipid metabolism and liver fat content in rats, and provide, and provide a reference for the further development of walnut meal functional foods.

[Cloning,expression and characterization of chalcone isomerase from medicinal plant Chinese sumac (Rhus chinensis)].

Flavonoids are a group of secondary metabolites found in plants. They have many pharmacological functions and play an important role in Chinese sumac( Rhus chinensis),which is a well-known traditional Chinese medicinal plant. Chalcone isomerase( CHI,EC 5. 5. 1. 6) is one of the key enzymes in the flavonoids biosynthesis pathway. In this paper,the full-length c DNA sequence encoding the chalcone isomerase from R. chinensis( designated as Rc CHI) was cloned by RT-PCR and rapid-amplification of c DNA Ends( RACE). The Rc CHI c DNA sequence was 1 058 bp and the open reading frame( ORF) was 738 bp. The ORF predicted to encode a 245-amino acid polypeptide. Rc CHI gene contained an intron and two exons. The sequence alignments revealed Rc CHI shared47. 1%-71. 6% identity with the homologues in other plants. Real-time PCR analysis showed that the total flavonoid levels were positively correlated with tissue-specific expressions of Rc CHI mRNA in different tissues. The recombinant protein was successfully expressed in an Escherichia coli strain with the p GEX-6 P-1 vector. In this paper,the CHI gene was cloned and characterized in the family of Anacardiaceae and will help us to obtain better knowledge of the flavonoids biosynthesis of the flavonoid compounds in R. chinensis.

Hetero-modification of TRAIL trimer for improved drug delivery and in vivo antitumor activities.

Poor pharmacokinetics and resistance within some tumor cell lines have been the major obstacles during the preclinical or clinical application of TRAIL (tumor-necrosis-factor (TNF)-related apoptosis-inducing ligand). The half-life of TRAIL114-281 (114 to 281 amino acids) was revealed to be no more than 30 minutes across species. Therefore maleimido activated PEG (polyethylene glycol) and MMAE (Monomethyl Auristatin E) were applied to site-specifically conjugate with the mutated cysteines from different monomers of TRAIL successively, taking advantage of steric effects involved within TRAIL mutant conjugations. As a result, TRAIL trimer was hetero-modified for different purposes. And the resulting PEG-TRAIL-vcMMAE conjugate exhibited dramatically improved half-life (11.54 h), favourable in vivo targeting capability and antitumor activities while no sign of toxicity in xenograft models, suggesting it's a viable therapeutic and drug delivery strategy.

Neuroprotective effect of resveratrol against glutamate-induced excitotoxicity.

As the major neurotransmitter in the mammalian central nervous system (CNS), excessive extracellular glutamate (Glu) can activate the Glu receptors and neuronal calcium (Ca2+) overload, then produce neurotoxicity, which is a common pathway for neuronal injury or death, and is associated with acute and chronic neurodegenerative diseases. Therefore, it has been a therapeutic strategy to investigate neuroprotective effects against Glu-induced neurotoxicity for treating both acute and chronic forms of neurodegeneration. Resveratrol (Res), as a naturally occurring polyphenol mainly found in grapes and red wine, has shown a neuroprotective effect in a variety of experimental models for neurodegenerative diseases in vitro and in vivo. This review will focus on the neuroprotective effect of Res against Glu-induced excitotoxicity in neurodegenerative diseases by blocking different Glu receptors and Ca2+ ion channels.

Stimuli-responsive blue fluorescent supramolecular polymers based on a pillar[5]arene tetramer.

A tetraphenylethene-bridged pillarene tetramer with aggregation-induced emission properties forms an A4/B2-type supramolecular polymer and a gel with a symmetric neutral guest linker, showing a remarkable fluorescence emission enhancement in solution and the solid state and a good responsiveness to temperature and solvent composition.

Correction method for the self-absorption effects in fluorescence extended X-ray absorption fine structure on multilayer samples.

A novel correction method for self-absorption effects is proposed for extended X-ray absorption fine structure (EXAFS) detected in the fluorescence mode on multilayer samples. The effects of refraction and multiple reflection at the interfaces are fully considered in this correction method. The correction is performed in k-space before any further data analysis, and it can be applied to single-layer or multilayer samples with flat surfaces and without thickness limit when the model parameters for the samples are known. The validity of this method is verified by the fluorescence EXAFS data collected for a Cr/C multilayer sample measured at different experimental geometries.