Disruption of LEAF LESION MIMIC 4 affects ABA synthesis and ROS accumulation in rice

Lesion mimic mutants(LMMs) are advantageous materials for studying programmed cell death(PCD).Although some rice LMM genes have been cloned, the diversity of functions of these genes indicates that the mechanism of cell death regulation in LMMs needs further study. In this study, we identified a rice light-dependent leaf lesion mimic mutant 4(llm4) that showed abnormal chloroplast structure, photoinhibition, reduced photosynthetic protein levels, massive accumulation of reactive oxygen species(ROS), and PCD. Map-based cloning and complementation testing revealed that LLM4 encodes zeaxanthin epoxidase(ZEP), an enzyme involved in the xanthophyll cycle, which functions in plant photoprotection,ROS scavenging, and carotenoid and abscisic acid(ABA) biosynthesis. The ABA content was decreased,and the contents of 24 carotenoids differed between the llm4 mutant and the wild type(WT). The llm4mutant showed reduced dormancy and greater sensitive to ABA than the WT. We concluded that the mutation of LLM4 resulted in the failure of xanthophyll cycle, in turn causing ROS accumulation. The excessive ROS accumulation damaged chloroplast structure and induced PCD, leading eventually to the formation of lesion mimics.

A centromere map based on super pan-genome highlights the structure and function of rice centromeres

Rice(Oryza sativa)is a significant crop worldwide with a genome shaped by various evolutionary factors.Rice centromeres are crucial for chromosome segregation,and contain some unreported genes.Due to the diverse and complex centromere region,a comprehensive understanding of rice centromere structure and function at the population level is needed.We constructed a high-quality centromere map based on the rice super pangenome consisting of a 251-accession panel comprising both cultivated and wild species of Asian and African rice.We showed that rice centromeres have diverse satellite repeat CentO,which vary across chromosomes and subpopulations,reflecting their distinct evolutionary patterns.We also revealed that long terminal repeats(LTRs),especially young Gypsy-type LTRs,are abundant in the peripheral CentO-enriched regions and drive rice centromere expansion and evolution.Furthermore,high-quality genome assembly and complete telomere-to-telomere(T2T)reference genome enable us to obtain more centromeric genome information despite mapping and cloning of centromere genes being challenging.We investigated the association between structural variations and gene expression in the rice centromere.A centromere gene,OsMAB,which positively regulates rice tiller number,was further confirmed by expression quantitative trait loci,haplotype analysis and clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein9 methods.By revealing the new insights into the evolutionary patterns and biological roles of rice centromeres,our finding will facilitate future research on centromere biology and crop improvement.

Leading High-Quality Development of Service Industry with Institutional Innovation

To realize the transition from high-speed growth to high-quality development,it is necessary not only to change the way and path of economic growth,but also to speed up the improvement of the institutional system that is compatible with highquality development.China has unique institutional advantages in promoting the high-quality development of the service industry(HQDSI),but the service industry is a typical institution-intensive industry that faces higher institutional barriers than the manufacturing industry.Therefore,institutional reform and business environment optimization are particularly important to the promotion of HQDSI,and the effect is also very prominent.Facing the future,we should lead HQDSI by building a high-standard socialist market economy,promote the high-quality and efficient development of the service industry by standardizing it,and encourage the innovation and entrepreneurship of the industry by improving the institutional environment,thus steadily boosting HQDSI in the new era of reform and opening up.

Resveratrol activation of SIRT1/MFN2 can improve mitochondria function,alleviating doxorubicin-induced myocardial injury

Background Doxorubicin is a widely used cytotoxic chemotherapy agent for treating different malignancies.However,its use is associated with dose-dependent cardiotoxicity,causing irreversible myocardial damage and significantly reducing the patient's quality of life and survival.In this study,an animal model of doxorubicin-induced cardiomyopathy was used to investigate the pathogenesis of doxorubicin-induced myocardial injury.This study also investigated a possible treatment strategy for alleviating myocardial injury through resveratrol therapy in vitro.Methods Adult male C57BL/6J mice were randomly divided into a control group and a doxorubicin group.Body weight,echocardiography,surface electrocardiogram,and myocardial histomorphology were measured.The mechanisms of doxorubicin cardiotoxicity in H9c2 cell lines were explored by comparing three groups(phosphate-buffered saline,doxorubicin,and doxorubicin with resveratrol).Results Compared to the control group,the doxorubicin group showed a lower body weight and higher systolic arterial pressure,associated with reduced left ventricular ejection fraction and left ventricular fractional shortening,prolonged PR interval,and QT interval.These abnormalities were associated with vacuolation and increased disorder in the mitochondria of cardiomyocytes,increased protein expression levels of α-smooth muscle actin and caspase 3,and reduced protein expression levels of Mitofusin2(MFN2)and Sirtuin1(SIRT1).Compared to the doxorubicin group,doxorubicin+resveratrol treatment reduced caspase 3 and manganese superoxide dismutase,and increased MFN2 and SIRT1 expression levels.Conclusion Doxorubicin toxicity leads to abnormal mitochondrial morphology and dysfunction in cardiomyocytes and induces apoptosis by interfering with mitochondrial fusion.Resveratrol ameliorates doxorubicin-induced cardiotoxicity by activating SIRT1/MFN2 to improve mitochondria function.

GR5 acts in the G protein pathway to regulate grain size in rice

Grain size is an important determinant of grain yield in rice.Although dozens of grain size genes have been reported,the molecular mechanisms that control grain size remain to be fully clarified.Here,we report the cloning and characterization of GR5(GRAIN ROUND 5),which is allelic to SMOS1/SHB/RLA1/NGR5 and en-codes an AP2 transcription factor.GR5 acts as a transcriptional activator and determines grain size by influencing cell proliferation and expansion.We demonstrated that GR5 physically interacts withfive Gg subunit proteins(RGG1,RGG2,DEP1,GS3,and GGC2)and acts downstream of the G protein complex.Four downstream target genes of GR5 in grain development(DEP2,DEP3,DRW1,and CyCD5;2)were re-vealed and their core T/CGCAC motif identified by yeast one-hybrid,EMSA,and ChIP–PCR experiments.Our results revealed that GR5 interacts with Gg subunits and cooperatively determines grain size by regu-lating the expression of downstream target genes.Thesefindings provide new insight into the genetic reg-ulatory network of the G protein signaling pathway in the control of grain size and provide a potential target for high-yield rice breeding.

Homoharringtonine synergy with oridonin in treatment of t(8;21) acute myeloid leukemia

Collaboration of c-KIT mutations with AML1-ETO (AE) has been demonstrated to induce t(8;21) acute myeloid leukemia (AML).Targeted therapies designed to eliminate AE and c-KIT oncoproteins may facilitate effective treatment of t(8;21) AML.Homoharringtonine (HHT) features activity against tumor cells harboring c-KIT mutations,whereas oridonin can induce t(8;21) AML cell apoptosis and AE cleavage.Therefore,studies should explore the efficacy of combination therapy with oridonin and HHT in t(8;21) AML.In this study,we investigated the synergistic effects and mechanism of oridonin combined with HHT in t(8;21) AML cell line and mouse model.The two drugs synergistically inhibited cell viability and induced significant mitochondrial membrane potential loss and apoptosis.Oridonin and HHT induced significant downregulation of c-KIT and its downstream signaling pathways and promoted AE cleavage.HHT increased intracellular oridonin concentration by modulating the expressions of MRP1 and MDR1,thus enhancing the effects of oridonin.The combination of oridonin and HHT prolonged t(8;21) leukemia mouse survival.In conclusion,oridonin and HHT exert synergistic effects against t(8;21) leukemia in vivo and in vitro,thereby indicating that their combination may be an effective therapy for t(8;21) leukemia.

Effect of the injection pressure and orifice diameter on the spray characteristics of biodiesel

The purpose of this study was to analyze the influence of the injection pressure and orifice diameter on the spray characteristics of soybean biodiesel.The macroscopic spray characteristics of the spray tip penetration(STP)and spray cone angle(SCA)were tested with a high-speed camera system.The microscopic spray characteristics,such as the statistical size distribution,Sauter mean diameter(SMD),representative diameters and dispersion boundary,were obtained using a Malvern laser particle size analyzer(PSA).The test results showed that with an increasing injection pressure,the STP and the SCA of the biodiesel increased,but the curves of size-volume distribution and cumulative volume distribution of the atomized droplets shifted to smaller diameters.The SMD and representative diameters decreased,and the dispersion boundary was reduced.Moreover,with a decreasing orifice diameter,longer STP and smaller SCA values were observed.Similarly,the size distribution curves of the atomized biodiesel droplets shifted to smaller diameters.The SMD and representative diameters were reduced,and the relative size range of the atomized biodiesel droplets was enlarged.Higher injection pressures and smaller orifice diameters improved the biodiesel atomization;however,the smaller orifice diameters caused an inhomogeneous size distribution of the atomized biodiesel droplets.

Event-triggered adaptive finite-time control for nonlinear systems under asymmetric time-varying state constraints

This paper investigates the issue of event-triggered adaptive finite-time state-constrained control for multi-input multi-output uncertain nonlinear systems.To prevent asymmetric time-varying state constraints from being violated,a tan-type nonlinear mapping is established to transform the considered system into an equivalent“non-constrained”system.By employing a smooth switch function in the virtual control signals,the singularity in the traditional finite-time dynamic surface control can be avoided.Fuzzy logic systems are used to compensate for the unknown functions.A suitable event-triggering rule is introduced to determine when to transmit the control laws.Through Lyapunov analysis,the closed-loop system is proved to be semi-globally practical finite-time stable,and the state constraints are never violated.Simulations are provided to evaluate the effectiveness of the proposed approach.

Tunable optical topological transition of Cherenkov radiation

Approaches to generate and manipulate Cherenkov radiation(CR)are challenging yet meaningful.Optical topological transition(OTT)in novel materials and metamaterials is also promising for modern photonics.We study the OTT of CR in graphene-based hyperbolic metamaterials(GHMs)for the first time.In GHMs,conventional and hyperbolic CR can be switched when crossing the topological transition frequency.This frequency can be altered by metamaterial components and external optical elements.For instance,external ultrafast optical pumps cause an ultrafast OTT from the elliptical to the hyperbolic state.Then,hyperbolic CR can be excited by lowenergy electrons by leveraging the excellent photothermal properties of graphene.Hyperbolic CR vanishes when the GHM returns to its original state.Furthermore,graphene nonlocality occurs when the electron velocity is low enough,corresponding to a large wave vector.Concretely,when the electron velocity approaches the Fermi velocity of graphene,a nonlocality-induced OTT modifies the plasmonic properties of the GHM and brings a new lower velocity threshold of hyperbolic CR.Therefore,hyperbolic CR can only be induced in a limited velocity range.These findings pave the way for understanding CR properties in active plasmonic metamaterials and may be applied to complex photonic and polaritonic systems.

Non-woven cotton fabric based intimately coupling of photocatalysis and biodegradation system for efficient removal of Cu(Ⅱ)complex in water

The efficient remediation of heavy metal complexes in water has become a difficult and challenging task owing to their high stability and strong mobility.In this study,a novel strategy was employed for highly efficient removal of Cu-citrate by using intimately coupled photocatalysis and biodegradation(ICPB)system with non-woven cotton fabric as a carrier.Experimental results showed that the ICPB system caused94%Cu removal,which was higher than those of single photocatalysis.After 5 cycles,Cu removal efficiency could still reach 78%within 5 h.The existence of 0–40 mg/L citrate had negligible influence,whereas the presence of 60–100 mg/L citrate exhibited a limited adverse effect on Cu removal(~70%).The decomplexation of Cu-citrate was realized via the function of free radicals and microorganisms.Two main processes,such as bio-adsorption of Cu^(2+) by microorganisms,deposition of Cu^(0) on the surface of material,played important role in Cu removal from aqueous solution.The dominant microorganisms in the system were Proteobacteria,Actinobacteria,Bacteroidetes,Chloroflexi,Chlorophyta,Planctomycetes,and Verrucomicrobia.Furthermore,the performance of ICPB system was also validated through treatment of other heavy metal complexes.This study provided a feasible strategy for the decontamination of heavy metal complexes in wastewater.