A petunia transcription factor, PhOBF1, regulates flower senescence by modulating gibberellin biosynthesis

Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins(GAs)in plants.However,the detailed mechanisms for the antagonism of these hormones during f lower senescence remain elusive.In this study,we characterized one up-regulated gene PhOBF1,belonging to the basic leucine zipper transcription factor family,in senescing petals of petunia(Petunia hybrida).Exogenous treatments with ethylene and GA3 provoked a dramatic increase in PhOBF1 transcripts.Compared with wild-type plants,PhOBF1-RNAi transgenic petunia plants exhibited shortened f lower longevity,while overexpression of PhOBF1 resulted in delayed flower senescence.Transcript abundances of two senescence-related genes PhSAG12 and PhSAG29 were higher in PhOBF1-silenced plants but lower in PhOBF1-overexpressing plants.Silencing and overexpression of PhOBF1 affected expression levels of a few genes involved in the GA biosynthesis and signaling pathways,as well as accumulation levels of bioactive GAs GA1 and GA3.Application of GA3 restored the accelerated petal senescence to normal levels in PhOBF1-RNAi transgenic petunia lines,and reduced ethylene release and transcription of three ethylene biosynthetic genes PhACO1,PhACS1,and PhACS2.Moreover,PhOBF1 was observed to specifically bind to the PhGA20ox3 promoter containing a G-box motif.Transient silencing of PhGA20ox3 in petunia plants through tobacco rattle virus-based virus-induced gene silencing method led to accelerated corolla senescence.Our results suggest that PhOBF1 functions as a negative regulator of ethylene-mediated f lower senescence by modulating the GA production.

Geological characteristics and shale gas distribution of carboniferous mudstones in the Tarim Basin,China

Extant research on Paleozoic mudstone is well developed in the Tarim Basin, while the research on Carboniferous mudstone is relatively weak. Through systematic study of lithology, geochemical characteristics,reservoir characteristics and gas–bearing properties of Carboniferous mudstone in the Tarim Basin, this study aims to provide a geological basis for the Paleozoic shale gas exploration and development, favorable zone optimization, and resource potential evaluation in the Tarim Basin. The results show that the sedimentary environments of organic-rich mudstone in the study area were mainly basin facies and slope facies. Lithology is dominated by black carbonaceous mudstone, followed by calcareous mudstone, siliceous mudstone, and siliceous rocks. Mudstone is mainly developed in the Kalashayi Formation,which is located in the Bachu and Markit slope belt, with the cumulative thickness of 30–200 m. The organic carbon content is commonly more than 0.4%, and the organic matter types are type II and type III. Thermal evolution degree is widely distributed from a low mature to over mature stage, and different tectonic units have a greater difference. The contents of quartz plus feldspar are between 12% and 82.5%, with an average of 45.8%. Thecontent distribution of clay mineral is from 12% to 57%,with an average of 38.2%. Carbonate minerals(mainly siderite) content is below 50%. The brittle mineral content of the mudstone is approximately 65%, with a strong compressibility, and the mudstone has the material basis of forming crack and natural fracture. Microscopic pores in micro–nanometer level are well developed in the mudstone, including micro bedding joint, microcrack,interbedded pores of clay mineral, nanoscale intragranular or edge pores in the massive organic matter, bioclastic micropores, and mineral dissolution pores, etc. According to the standards provided by the Ministry of Land and Resources in China, the Kalashayi Formation in Bamai Area is a favorable area for shale gas development.

Regulation of endogenous retroviruses in murine embryonic stem cells and early embryos

Endogenous retroviruses(ERVs)are important components of transposable elements that constitute∼40%of the mouse genome.ERVs exhibit dynamic expression patterns during early embryonic development and are engaged in numerous biological processes.Therefore,ERV expression must be closely monitored in cells.Most studies have focused on the regulation of ERV expression in mouse embryonic stem cells(ESCs)and during early embryonic development.This review touches on the classification,expression,and functions of ERVs in mouse ESCs and early embryos and mainly discusses ERV modulation strategies from the perspectives of transcription,epigenetic modification,nucleosome/chromatin assembly,and post-transcriptional control.

STING and TLR9 agonists synergistically enhance the immunogenicity of SARS-CoV-2 subunit vaccine

Vaccines that are reliable and efficacious are essential in the fight against the COVID-19 pandemic.In this study,we designed a dual-adjuvant system with two pathogen-associated molecular patterns(PAMPs),MnOx and CpG.This system can improve the retention of antigens at the injection site,facilitate pro-inflammatory cytokines secretion,further recruit and activate dendritic cells(DCs).As a result,antigens can be delivered to lymph nodes specifically,and adaptive immunity was strengthened.The immunized group showed an enhanced and broadened humoral and cellular immune response in systemic immunity and lung protection when combined with a tandem repeat-linked dimeric antigen version of the SARS-CoV-2 receptor binding domain(RBDdimer).Remarkably,even with a significant reduction in antigen dosage(three times lower)and a decrease in injection frequencies,our nanovaccine was able to produce the highest neutralizing antibody titers against various mutants.These titers were four-fold higher for the wild-type strain and two-fold higher for both the Beta and Omicron variants in comparison with those elicited by the Alum adjuvant group.In conclusion,our dual-adjuvant formulation presents a promising protein subunit-based candidate vaccine against SARS-CoV-2.

Cannabidiol prevents depressive-like behaviors through the modulation of neural stem cell differentiation

Chronic stress impairs radial neural stem cell(rNSC)differentiation and adult hippocampal neurogenesis(AHN),whereas promoting AHN can increase stress resilience against depression.Therefore,investigating the mechanism of neural differentiation and AHN is of great importance for developing antidepressant drugs.The nonpsychoactive phytocannabinoid cannabidiol(CBD)has been shown to be effective against depression.However,whether CBD can modulate rNSC differentiation and hippocampal neurogenesis is unknown.Here,by using the chronic restraint stress(CRS)mouse model,we showed that hippocampal rNSCs mostly differentiated into astrocytes under stress conditions.Moreover,transcriptome analysis revealed that the FoxO signaling pathway was involved in the regulation of this process.The administration of CBD rescued depressive-like symptoms in CRS mice and prevented rNSCs overactivation and differentiation into astrocyte,which was partly mediated by the modulation of the FoxO signaling pathway.These results revealed a previously unknown neural mechanism for neural differentiation and AHN in depression and provided mechanistic insights into the antidepressive effects of CBD.