Carotenoids are essential components in tea quality, contributing to leaf color and aroma. However, little information about carotenoids in different tea cultivars and their biosynthesis regulation mechanism during le...Carotenoids are essential components in tea quality, contributing to leaf color and aroma. However, little information about carotenoids in different tea cultivars and their biosynthesis regulation mechanism during leaf development is known. Here we analyzed carotenoids by HPLC in the buds and leaves of 113 tea cultivars harvested on the same day. By profile clustering, carotenoids were divided into five groups. Same group cultivars displayed divergence in the total content of carotenoids but a similar molar ratio. To figure out the molecular mechanisms of this phenomenon, we further characterized all functional lycopene cyclases, which are the branch point of the carotenoid biosynthesis pathway. Two β-lycopene cyclases(CsLCYB1 and CsLCYB2) and one ε-lycopene cyclase(CsLCYE1) were cloned. Subcellular localization analysis showed that all cloned CsLCYs were localized in plastids. Enzyme activity assays in E. coli indicated both CsLCYBs catalyzed lycopene into β-carotene, and CsLCYE1 produced δ-carotene and ε-carotene. We found CsLCYB1 and CsLCYE1 predominantly expressed in leaf, while CsLCYB2was mainly expressed during flowering stages. Suppression by antisense oligonucleotides reduced CsLCYB1 and CsLCYE1 transcripts and led to reduction of both β,β-branch and β,ε-branch carotenoids in leaf. The expression levels of CsLCYB1 showed a significant positive correlation withβ,β-branch carotenoids in leaf. Our study provides carotenoid profiles of different tea cultivars, which can assist tea producers in selecting cultivars of interest. Meanwhile, we proposed the molecular mechanism of carotenoids reflecting the tenderness of tea plant leaf from a metabolic flux perspective, and suggested lycopene cyclase that could be applied to the breeding of tea varieties with different branch carotenoids.展开更多
The breeding and large-scale application of hybrid rice contribute significantly to the food supply worldwide.Currently,hybrid seed production uses cytoplasmic male sterile(CMS)lines or photoperiod/thermo-sensitive ge...The breeding and large-scale application of hybrid rice contribute significantly to the food supply worldwide.Currently,hybrid seed production uses cytoplasmic male sterile(CMS)lines or photoperiod/thermo-sensitive genic male sterile(PTGMS)lines as female parent.Despite huge successes,both systems have intrinsic problems.CMS systems are mainly restricted by the narrow restorer resources that make it difficult to breed superior hybrids,while PTGMS systems are limited by conditional sterility of the male sterile lines that makes the propagation of both PTGMS seeds and hybrid seeds vulnerable to unpredictable climate changes.Recessive nuclear male sterile(NMS)lines insensitive to environmental conditions are widely distributed and are ideal for hybrid rice breeding and production,but the lack of effective ways to propagate the pure NMS lines in a large scale renders it impossible to use them for hybrid rice production.The development of"the third-generation hybrid rice technology"enables efficient propagation of the pure NMS lines in commercial scale.This paper discusses the establishment of"the thirdgeneration hybrid rice technology"and further innovations.This new technology breaks the limitations of CMS and PTGMS systems and will bring a big leap forward in hybrid rice production.展开更多
Rice is one of the most important food crops in the world.Weeds seriously affect the rice yield and grain quality.In recent years,there are tremendous progresses in the research and application of herbicideresistant g...Rice is one of the most important food crops in the world.Weeds seriously affect the rice yield and grain quality.In recent years,there are tremendous progresses in the research and application of herbicideresistant genes in rice worldwide.This article reviews the working mechanisms of six herbicides(glyphosate,glufosinate,acetolactate synthase inhibitor herbicides,acetyl-Co A carboxylase inhibitor herbicides,hydroxyhenylpyruvate dioxygenase(HPPD)inhibitor herbicides and dinitroaniline herbicides),the resistance mutations of the corresponding herbicide-target genes,and the herbicide detoxification mechanisms by non-target genes.Examples are provided on herbicide-resistant rice materials obtained by transformation of exogenous resistance genes,by artificial mutagenesis and mutant screening,and by modifying the target genes through gene editing.This paper also introduces the current application of herbicide-resistant rice,points out problems that may be caused by utilization of herbicide resistant rice and solutions to the problems,and discusses the future prospects for the development of herbicideresistant rice.展开更多
Herbicide resistance in crop plants is valuable for integrated weed management in agriculture. Herbicide resistant rice, in particular, is important to management of weedy rice, a close relative of cultivated rice and...Herbicide resistance in crop plants is valuable for integrated weed management in agriculture. Herbicide resistant rice, in particular, is important to management of weedy rice, a close relative of cultivated rice and a noxious weed prevalent in rice fields that remains challenging to farmers worldwide. Herbicide resistant plants can be obtained through transgenic approach or by mutagenesis of regular plant and screening of mutants with elevated resistance to herbicide. In this study, we conducted ethyl methyl sulfonate mutagenesis(EMS) to elite indica cultivar Huanghuazhan(HHZ) and screened for mutants resistant to imazapic, a herbicide that can inhibit the acetolactate synthase(ALS) in plants. We obtained three mutants of Os ALS gene that have not been reported previously in rice. One of the mutants, with Trp_(548) changed to Met(W_(548)M), was analyzed in more details in this study. This mutation had no negative effect on the plant physiology and morphology as well as rice yield. Compared with the imidazolinone-resistant mutant S_(627)N(Ser_(627) changed to Asn) that has been deployed for Clearfield rice development, W_(548)M mutant showed high levels of resistance to a broad spectrum of five families of ALSinhibiting herbicides, in addition to a higher level of resistance to herbicides of the imidazolinone family.The herbicide-resistance was stably inherited by crossing into other rice lines. Thus, the W_(548)M mutation provides a valuable resource for breeding of herbicide resistant rice and weed management.展开更多
TaMs1 encodes a non-specific lipid transfer protein(nsLTP) and is required for pollen development in wheat. Although MS1 is a Poaceae-specific gene, the roles of MS1 genes in other Poaceae plants are unknown, especial...TaMs1 encodes a non-specific lipid transfer protein(nsLTP) and is required for pollen development in wheat. Although MS1 is a Poaceae-specific gene, the roles of MS1 genes in other Poaceae plants are unknown, especially in rice and maize. Here, we identified one ortholog in rice(OsLTPg29) and two orthologs in maize(ZmLTPg11 and ZmLTPx2). Similar to TaMs1, both OsLTPg29 and ZmLTPg11 genes are specifically expressed in the microsporocytes, and both OsLTPg29 and ZmLTPg11 proteins showed lipid-binding ability to phosphatidic acid and several phosphoinositides. To determine their roles in pollen development, we created osltpg29 mutants and zmltpg11 zmltpx2 double mutants by CRISPR/Cas9.osltpg29, not zmltpg11 zmltpx2, is defective in pollen development, and only OsLTPg29, not ZmLTPg11,can rescue the male sterility of tams1 mutant. Our results demonstrate that the biological function of MS1 in pollen development differs in the evolution of Poaceae plants.展开更多
The recovery rate of coalbed methane (CBM) can reflect the mining situation and the residual gas in coal reservoir. It plays an important role in the calculation of the recoverable resources. This paper mainly uses is...The recovery rate of coalbed methane (CBM) can reflect the mining situation and the residual gas in coal reservoir. It plays an important role in the calculation of the recoverable resources. This paper mainly uses isothermal adsorption curve method and hydraulic model method to predict recovery rate of CBM. The isothermal adsorption curve method considering desorption lag problem in the prediction process, which is more in line with the actual situation. In the hydraulic model method, the recovery rate of “V” type well is the largest in the early stage. But with the time going on, the recovery rate of multilateral horizontal well is greater than vertical well, “U” type well and “V” type well finally. The factors affecting CBM recovery rate include geological characteristics, development conditions and economic factors. The geological characteristics of coal reservoir are the main factors affecting CBM recovery rate, and corresponding measures can be adopted to improve the recovery rate.展开更多
Poly(3-hydroxybutyrate),a crucial member of the large biodegradable polyhydroxyalkanoate family,suffers from its brittleness.To enhance its performance,we employed a straightforward approach involving the ring-opening...Poly(3-hydroxybutyrate),a crucial member of the large biodegradable polyhydroxyalkanoate family,suffers from its brittleness.To enhance its performance,we employed a straightforward approach involving the ring-opening copolymerization of racemic-β-butyrolactone(rac-β-BL)andβ-propiolactone(β-PL)using the syndio-selective amino-alkoxy-bis(phenolate)-yttrium complex as a catalyst,thanks to the excellent ductility of poly(3-hydroxypropionate).Control over the rac-β-BL/β-PL feeding ratios and polymerization time yielded random or block copolymers with tunable thermal and mechanical properties comparable to traditional fossil-based plastics.Furthermore,we achieved one-pot synthesis of hard-soft-hard triblock copolymers by exploiting monomers’different copolymerization rates and a bifunctional initiator,thus transforming polyhydroxyalkanoates from hard and tough plastics to soft and ductile thermoplastic elastomers.展开更多
With the development of agricultural technology to meet the growing demands of a rapidly increasing population and economic development,intensive agriculture practices have been widely adopted globally. However,this i...With the development of agricultural technology to meet the growing demands of a rapidly increasing population and economic development,intensive agriculture practices have been widely adopted globally. However,this intensification has resulted in adverse consequences for soil structure due to intensified farming activities and increased usage of heavy farm machinery.Of particular concern is soil compaction, which leads to the degradation of physical, chemical and biological properties of the soil. Soil compaction negatively impacts crop growth, reduces yields and poses a significant threat to food security and the overall sustainability of agricultural systems.Recognizing these challenges, this review aims to deepen understanding of the factors contributing to soil compaction and to develop effective mitigation strategies. By doing so, it is intended to attenuate the adverse impacts of soil compaction, improve soil structure, increase crop yield and ultimately enhance the sustainability of agricultural practices.展开更多
The short lifespan of most commercial plastics as disposables and the failure to adequately address the end-of-life issues of synthetic polymers have led to outrageous global plastic pollution and resource depletion.T...The short lifespan of most commercial plastics as disposables and the failure to adequately address the end-of-life issues of synthetic polymers have led to outrageous global plastic pollution and resource depletion.To solve the problem,one of the most effective strategies is to develop circular polymers and thus establish a new circular material economy.Polymers from ring-opening polymerization of five-membered(thio)lactones contribute greatly to this field due to their excellent material performance and recyclability.The emerging topic emphasizes on the monomer design strategies based on five-membered(thio)lactones,and compares the thermal and mechanical properties and depolymerizability of the resulting polymers with different structures.展开更多
A high-density single nucleotide polymorphism (SNP) array is critically important for geneticists and molecu- lar breeders. With the accumulation of huge amounts of genomic re-sequencing data and available technolog...A high-density single nucleotide polymorphism (SNP) array is critically important for geneticists and molecu- lar breeders. With the accumulation of huge amounts of genomic re-sequencing data and available technologies for accurate SNP detection, it is possible to design high-density and high-quality rice SNP arrays. Here we report the devel- opment of a high-density rice SNP array and its utility. SNP probes were designed by screening more than 10 000 000 SNP loci extracted from the re-sequencing data of 801 rice varieties and an array named RiceSNP50 was produced on the Illumina Infinium platform. The array contained 51 478 evenly distributed markers, 68% of which were within genic regions. Several hundred rice plants with parent/F1 relationships were used to generate a high-quality cluster file for accurate SNP calling. Application tests showed that this array had high genotyping accuracy, and could be used for dif- ferent objectives. For example, a core collection of elite rice varieties was clustered with fine resolution. Genome-wide association studies (GWAS) analysis correctly identified a characterized QTL. Further, this array was successfully used for variety verification and trait introgression. As an accurate high-throughput genotyping tool, RiceSNP50 will play an important role in both functional genomics studies and molecular breeding.展开更多
Objective:Safe and effective anticoagulation is essential for hemodialysis patients who are at high risk of bleeding.The purpose of this trial is to evaluate the effectiveness and safety of two-stage regional citrate ...Objective:Safe and effective anticoagulation is essential for hemodialysis patients who are at high risk of bleeding.The purpose of this trial is to evaluate the effectiveness and safety of two-stage regional citrate anticoagulation(RCA)combined with sequential anticoagulation and standard calcium-containing dialysate in intermittent hemodialysis(IHD)treatment.Methods:Patients at high risk of bleeding who underwent IHD from September 2019 to May 2021 were prospectively enrolled in 13 blood purification centers of nephrology departments,and were randomly divided into RCA group and saline flushing group.In the RCA group,0.04 g/mL sodium citrate was infused from the start of the dialysis line during blood draining and at the venous expansion chamber.The sodium citrate was stopped after 3 h of dialysis,which was changed to sequential dialysis without anticoagulant.The hazard ratios for coagulation were according to baseline.Results:A total of 159 patients and 208 sessions were enrolled,including RCA group(80 patients,110 sessions)and saline flushing group(79 patients,98 sessions).The incidence of severe coagulation events of extracorporeal circulation in the RCA group was significantly lower than that in the saline flushing group(3.64%vs.20.41%,P<0.001).The survival time of the filter pipeline in the RCA group was significantly longer than that in the saline flushing group((238.34±9.33)min vs.(221.73±34.10)min,P<0.001).The urea clearance index(Kt/V)in the RCA group was similar to that in the saline flushing group with no statistically significant difference(1.12±0.34 vs.1.08±0.34,P=0.41).Conclusions:Compared with saline flushing,the two-stage RCA combined with a sequential anticoagulation strategy significantly reduced extracorporeal circulation clotting events and prolonged the dialysis time without serious adverse events.展开更多
The adsorption behavior of 2-mercaptobenzothiazole onto organo-bentonite was investigated. Natural bentonite from Gaozhou in Guangdong Province, China was collected. Organo-bentonite was prepared by intercalation of c...The adsorption behavior of 2-mercaptobenzothiazole onto organo-bentonite was investigated. Natural bentonite from Gaozhou in Guangdong Province, China was collected. Organo-bentonite was prepared by intercalation of cetyltrimethyl ammonium bromide into the natural bentonite. The physicochemical properties of the prepared organo-bentonite were characterized by X-ray diffraction, N2 adsorption-desorption isotherm and Fourier transform infrared spectroscopy. The results showed that montmorillonite is the main component of the natural bentonite. The basal spacing of the natural bentonite is 1.47 nm, which increased to 1.98 nm on intercalation with cetyltrimethyl ammonium bromide. Moreover, both the surface area and pore volume increased with intercalation. Clear CH2 stretching (3000-2800 cm-1) and scissoring (1480-1450 cm-1) modes of the intercalated surfactants were observed for organo- bentonite. Compared with the pseudo first-order kinetic model, the pseudo second-order kinetic model is more suitable to describe the adsorption kinetics of 2-mercaptobenzothiazole onto organo-bentonite. The adsorption capacity of 2-mercaptobenzothiazole onto organo-bentonite increased with increasing initial concentration of 2-mercaptobenzothiazole, but decreased with increasing adsorbent dosage. The adsorption isotherm of 2-mercaptobenzothiazole onto organo-bentonite fits well with the Langmuir model. The maximum adsorption capacity of organo-bentonite for 2-mercaptobenzothiazole was 33.61 mg/g, indicating that organo-bentonite is a promising adsorbent for 2-mercaptobenzothiazole.展开更多
Pollen exine contains complex biopolymers of aliphatic lipids and phenolics.Abnormal development of pollen exine often leads to plant sterility.Molecular mechanisms regulating exine formation have been studied extensi...Pollen exine contains complex biopolymers of aliphatic lipids and phenolics.Abnormal development of pollen exine often leads to plant sterility.Molecular mechanisms regulating exine formation have been studied extensively but remain ambiguous.Here we report the analyses of three GDSL esterase/lipase protein genes,OsGELP34,OsGELP110,and OsGELP115,for rice exine for-mation.OsGELP34 was identified by cloning of a male sterile mutant gene.OsGELP34 encodes an endoplasmic reticulum protein and was mainly expressed in anthers during pollen exine formation.osgelp34 mutant displayed abnormal exine and altered expression of a number of key genes required for pollen development.OsGELP110 was previously identified as a gene differentially expressed in meiotic anthers.OsGELP110 was most homologous to OsGELP115,and the two genes showed similar gene expression patterns.Both OsGELP110 and OsGELP115 proteins were localized in peroxisomes.Individual knockout of OsGELP110 and OsGELP115 did not affect the plant fertility,but double knockout of both genes altered the exine structure and rendered the plant male sterile.OsGELP34 is distant from OsGELP110 and OsGELP115 in sequence,and osgelp34 and osgelp110/osgelp115 mutants were different in anther morphology despite both were male sterile.These results suggested that OsGELP34 and OsGELP110/OsGELP115 catalyze different compounds for pollen exine development.展开更多
Pollen grains are covered by exine that protects the pollen from stress and facilitates pollination.Here we isolated a male sterile mutant s13283 in rice exhibiting aborted pollen with abnormal exine and defective ape...Pollen grains are covered by exine that protects the pollen from stress and facilitates pollination.Here we isolated a male sterile mutant s13283 in rice exhibiting aborted pollen with abnormal exine and defective aperture.The mutant gene encodes a novel plasma membrane-localized legume-lectin receptor kinase that we named OsLecRK-S.7.OsLecRK-S.7 was expressed at different levels in all tested tissues and throughout anther development.In vitro kinase assay showed OsLecRK-S.7 capable of autophosporylation.Mutation in s13283(E560K)and mutation of the conserved ATP binding site(K418E)both knocked out the kinase activity.Mass spectrometry showed Thr376,Ser378,Thr386,Thr403,and Thr657 to be the autophosphorylation sites.Mutation of individual autophosphorylation site affected the in vitro kinase activity to different degrees,but did not abolish the gene function in fertility complementation.oslecrk-s.7 mutant plant overexpressing OsLecRK-S.7 recovered male fertility but showed severe growth retardation with reduced number of tillers,and these phenotypes were abolished by E560K or K418E mutation.The results indicated that OsLecRK-S.7 was a key regulator of pollen development.展开更多
Lignin-degrading enzymes secreted by white rot fungi play an important role in the degradation of lignin and persistent organic pollutants(POPs).In this study,effect of environmental C/N ratio on the activities of lig...Lignin-degrading enzymes secreted by white rot fungi play an important role in the degradation of lignin and persistent organic pollutants(POPs).In this study,effect of environmental C/N ratio on the activities of lignin-degrading enzymes,lignin peroxide(Li P)and manganese peroxidase(Mn P),produced by Phanerochaete chrysosporium,a white rot fungus,was investigated.Glucose was used as C source,and ammonium tartrate of different concentrations was used as N source to provide different C/N ratios.Relationships between Li P and Mn P activities and environmental C/N ratio were explored.The results showed that the higher the N source concentration,the faster the mycelium pellets aged.The faster the mycelium dry weight increased,the higher the Li P and Mn P activities.A high C/N ratio was a necessary condition for the secretion of Li P or Mn P.In addition,mycelium dry weight essentially affected enzyme activities.In the 122 C/N ratio and 50 C/N ratio treatments,mycelium dry weight essentially affected Mn P activity and both Li P and Mn P activities,respectively.展开更多
PM(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM(2.5) concentrations and annual avera...PM(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM(2.5) concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM(2.5) pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days(daily PM32.5 concentrations &gt; 250 μg/mand visibility &lt; 3 km) than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO-3/SO2-4,stationary sources are still the dominant source of PM(2.5) and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days.Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources(i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust,vehicle, and industry) of PM(2.5) were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively.Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode(Jan 1-9, 2015) and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM(2.5) in the study area was aggravated.展开更多
Large-scale production of male sterile seeds can be achieved by introducing a fertility-restoration gene linked with a pollen-killer gene into a recessive male sterile mutant.We attempted to construct this system in r...Large-scale production of male sterile seeds can be achieved by introducing a fertility-restoration gene linked with a pollen-killer gene into a recessive male sterile mutant.We attempted to construct this system in rice by using a late-stage pollen-specific(LSP)promoter driving the expression of maizeα-amylase gene ZM-AA1.To obtain such promoters in rice,we conducted comparative RNA-seq analysis of mature pollen with meiosis anther,and compared this with the transcriptomic data of various tissues in the Rice Expression Database,resulting in 269 candidate LSP genes.Initial test of nine LSP genes showed that only the most active OsLSP3 promoter could drive ZM-AA1 to disrupt pollen.We then analyzed an additional 22 LSP genes and found 12 genes stronger than OsLSP3 in late-stage anthers.The promoters of OsLSP5 and OsLSP6 showing higher expression than OsLSP3 at stages 11 and 12 could drive ZM-AA1 to inactivate pollen,while the promoter of OsLSP4 showing higher expression at stage 12 only could not drive ZM-AA1 to disrupt pollen,suggesting that strong promoter activity at stage 11 was critical for pollen inactivation.The strong pollen-specific promoters identified in this study provided valuable tools for genetic engineering of rice male sterile system for hybrid rice production.展开更多
Selective immunoglobulin A deficiency(SIgAD)is considered to be the most common human primary immune-deficiency disease in the world.However,the incidence in China is obviously lower than Caucasian races.The definitio...Selective immunoglobulin A deficiency(SIgAD)is considered to be the most common human primary immune-deficiency disease in the world.However,the incidence in China is obviously lower than Caucasian races.The definition of SIgAD has changed over time with the progress of people’s understanding.The scientific community did not reach a consensus on the definition until 1999.As a result,many previously reported cases need to be excluded under the current definition.SIgAD can lead to several spectra of diseases including infections and autoimmune diseases.We retrospectively summarized the SIgAD patients in Peking Union Medical College Hospital(PUMCH),and summarized the Chinese SIgAD reported in China and abroad in past 40 years.Fourty three SIgAD patients were confirmed in the study,in which 9 were healthy without clinical symptoms.Of the 34 patients with clinical symptoms,recurrent infections were found in 29(85.3%)patients;13(38.2%)patients were with autoimmune diseases;6(17.6%)cases had allergic symptoms;3 patients(8.8%)were with tumors,only one case(2.9%)had a family history.Compared with other countries,sIgAD patients in China showed similar symptoms,but the rate of recurrent infections and autoimmune diseases were higher than some other countries;most of the allergic symptoms are drug allergy,different with the allergic sequelae reported in other countries,such as asthma,rhinitis,food allergy and atopic dermatitis;and it is rare to have family history in Chinese patients.We also figured out that more female SIgAD patients tend to have more autoimmune diseases than men(P=0.039).展开更多
基金supported by grants from the National Natural Science Foundation of China (Grant No.32102433)。
文摘Carotenoids are essential components in tea quality, contributing to leaf color and aroma. However, little information about carotenoids in different tea cultivars and their biosynthesis regulation mechanism during leaf development is known. Here we analyzed carotenoids by HPLC in the buds and leaves of 113 tea cultivars harvested on the same day. By profile clustering, carotenoids were divided into five groups. Same group cultivars displayed divergence in the total content of carotenoids but a similar molar ratio. To figure out the molecular mechanisms of this phenomenon, we further characterized all functional lycopene cyclases, which are the branch point of the carotenoid biosynthesis pathway. Two β-lycopene cyclases(CsLCYB1 and CsLCYB2) and one ε-lycopene cyclase(CsLCYE1) were cloned. Subcellular localization analysis showed that all cloned CsLCYs were localized in plastids. Enzyme activity assays in E. coli indicated both CsLCYBs catalyzed lycopene into β-carotene, and CsLCYE1 produced δ-carotene and ε-carotene. We found CsLCYB1 and CsLCYE1 predominantly expressed in leaf, while CsLCYB2was mainly expressed during flowering stages. Suppression by antisense oligonucleotides reduced CsLCYB1 and CsLCYE1 transcripts and led to reduction of both β,β-branch and β,ε-branch carotenoids in leaf. The expression levels of CsLCYB1 showed a significant positive correlation withβ,β-branch carotenoids in leaf. Our study provides carotenoid profiles of different tea cultivars, which can assist tea producers in selecting cultivars of interest. Meanwhile, we proposed the molecular mechanism of carotenoids reflecting the tenderness of tea plant leaf from a metabolic flux perspective, and suggested lycopene cyclase that could be applied to the breeding of tea varieties with different branch carotenoids.
基金supported by the National Natural Science Foundation of China(U1901203)Natural Science Foundation of Guangdong Province(2018B030308008 and 2019A1515110671)+2 种基金Major Program of Guangdong Basic and Applied Research(2019B030302006)Shenzhen Commission on Innovation and Technology Programs(JCYJ20180507181837997)China Postdoctoral Science Foundation(2019M662957)。
文摘The breeding and large-scale application of hybrid rice contribute significantly to the food supply worldwide.Currently,hybrid seed production uses cytoplasmic male sterile(CMS)lines or photoperiod/thermo-sensitive genic male sterile(PTGMS)lines as female parent.Despite huge successes,both systems have intrinsic problems.CMS systems are mainly restricted by the narrow restorer resources that make it difficult to breed superior hybrids,while PTGMS systems are limited by conditional sterility of the male sterile lines that makes the propagation of both PTGMS seeds and hybrid seeds vulnerable to unpredictable climate changes.Recessive nuclear male sterile(NMS)lines insensitive to environmental conditions are widely distributed and are ideal for hybrid rice breeding and production,but the lack of effective ways to propagate the pure NMS lines in a large scale renders it impossible to use them for hybrid rice production.The development of"the third-generation hybrid rice technology"enables efficient propagation of the pure NMS lines in commercial scale.This paper discusses the establishment of"the thirdgeneration hybrid rice technology"and further innovations.This new technology breaks the limitations of CMS and PTGMS systems and will bring a big leap forward in hybrid rice production.
基金supported by the Natural Science Foundation of Guangdong Province(2018B030308008)National Natural Science Foundation of China(U1901203 and 31901532)+2 种基金Major Program of Guangdong Basic and Applied Research(2019B030302006)Shenzhen Commission on Innovation and Technology Programs JCYJ20180507181837997)China Postdoctoral Science Foundation(2018 M633069 and 2019 M652920)。
文摘Rice is one of the most important food crops in the world.Weeds seriously affect the rice yield and grain quality.In recent years,there are tremendous progresses in the research and application of herbicideresistant genes in rice worldwide.This article reviews the working mechanisms of six herbicides(glyphosate,glufosinate,acetolactate synthase inhibitor herbicides,acetyl-Co A carboxylase inhibitor herbicides,hydroxyhenylpyruvate dioxygenase(HPPD)inhibitor herbicides and dinitroaniline herbicides),the resistance mutations of the corresponding herbicide-target genes,and the herbicide detoxification mechanisms by non-target genes.Examples are provided on herbicide-resistant rice materials obtained by transformation of exogenous resistance genes,by artificial mutagenesis and mutant screening,and by modifying the target genes through gene editing.This paper also introduces the current application of herbicide-resistant rice,points out problems that may be caused by utilization of herbicide resistant rice and solutions to the problems,and discusses the future prospects for the development of herbicideresistant rice.
基金supported by Major Program of Guangdong Basic and Applied Research(2019B030302006)National Natural Science Foundation of China(U1901203 and 31901532)+2 种基金Natural Science Foundation of Guangdong Province(2018B030308008 and 2018A0303130270)Shenzhen Commission on Innovation and Technology Programs(JCYJ20180507181837997)China Postdoctoral Science Foundation(2018M633069 and 2019M652920)。
文摘Herbicide resistance in crop plants is valuable for integrated weed management in agriculture. Herbicide resistant rice, in particular, is important to management of weedy rice, a close relative of cultivated rice and a noxious weed prevalent in rice fields that remains challenging to farmers worldwide. Herbicide resistant plants can be obtained through transgenic approach or by mutagenesis of regular plant and screening of mutants with elevated resistance to herbicide. In this study, we conducted ethyl methyl sulfonate mutagenesis(EMS) to elite indica cultivar Huanghuazhan(HHZ) and screened for mutants resistant to imazapic, a herbicide that can inhibit the acetolactate synthase(ALS) in plants. We obtained three mutants of Os ALS gene that have not been reported previously in rice. One of the mutants, with Trp_(548) changed to Met(W_(548)M), was analyzed in more details in this study. This mutation had no negative effect on the plant physiology and morphology as well as rice yield. Compared with the imidazolinone-resistant mutant S_(627)N(Ser_(627) changed to Asn) that has been deployed for Clearfield rice development, W_(548)M mutant showed high levels of resistance to a broad spectrum of five families of ALSinhibiting herbicides, in addition to a higher level of resistance to herbicides of the imidazolinone family.The herbicide-resistance was stably inherited by crossing into other rice lines. Thus, the W_(548)M mutation provides a valuable resource for breeding of herbicide resistant rice and weed management.
基金supported by Peking University Institute of Advanced Agricultural Sciences, and Beijing Municipal Government Science Foundation (IDHT20170513)。
文摘TaMs1 encodes a non-specific lipid transfer protein(nsLTP) and is required for pollen development in wheat. Although MS1 is a Poaceae-specific gene, the roles of MS1 genes in other Poaceae plants are unknown, especially in rice and maize. Here, we identified one ortholog in rice(OsLTPg29) and two orthologs in maize(ZmLTPg11 and ZmLTPx2). Similar to TaMs1, both OsLTPg29 and ZmLTPg11 genes are specifically expressed in the microsporocytes, and both OsLTPg29 and ZmLTPg11 proteins showed lipid-binding ability to phosphatidic acid and several phosphoinositides. To determine their roles in pollen development, we created osltpg29 mutants and zmltpg11 zmltpx2 double mutants by CRISPR/Cas9.osltpg29, not zmltpg11 zmltpx2, is defective in pollen development, and only OsLTPg29, not ZmLTPg11,can rescue the male sterility of tams1 mutant. Our results demonstrate that the biological function of MS1 in pollen development differs in the evolution of Poaceae plants.
文摘The recovery rate of coalbed methane (CBM) can reflect the mining situation and the residual gas in coal reservoir. It plays an important role in the calculation of the recoverable resources. This paper mainly uses isothermal adsorption curve method and hydraulic model method to predict recovery rate of CBM. The isothermal adsorption curve method considering desorption lag problem in the prediction process, which is more in line with the actual situation. In the hydraulic model method, the recovery rate of “V” type well is the largest in the early stage. But with the time going on, the recovery rate of multilateral horizontal well is greater than vertical well, “U” type well and “V” type well finally. The factors affecting CBM recovery rate include geological characteristics, development conditions and economic factors. The geological characteristics of coal reservoir are the main factors affecting CBM recovery rate, and corresponding measures can be adopted to improve the recovery rate.
基金supported by the National Natural Science Foundation of China(No.52173093)Peking University Ge Li and Ning Zhao Life Science Research Fund for Young Scientists。
文摘Poly(3-hydroxybutyrate),a crucial member of the large biodegradable polyhydroxyalkanoate family,suffers from its brittleness.To enhance its performance,we employed a straightforward approach involving the ring-opening copolymerization of racemic-β-butyrolactone(rac-β-BL)andβ-propiolactone(β-PL)using the syndio-selective amino-alkoxy-bis(phenolate)-yttrium complex as a catalyst,thanks to the excellent ductility of poly(3-hydroxypropionate).Control over the rac-β-BL/β-PL feeding ratios and polymerization time yielded random or block copolymers with tunable thermal and mechanical properties comparable to traditional fossil-based plastics.Furthermore,we achieved one-pot synthesis of hard-soft-hard triblock copolymers by exploiting monomers’different copolymerization rates and a bifunctional initiator,thus transforming polyhydroxyalkanoates from hard and tough plastics to soft and ductile thermoplastic elastomers.
基金supported by the Yunnan Science and Technology Program (202202AE090034)the National Key R&D Program of China (2021YFD1901002-5, 2022YFD1901504-2) to Kemo Jin+2 种基金supported by the Sichuan Science and Technology Program (2022YFQ0091) to Xiaoyan Tangsupported by the National Natural Science Foundation of China (31800378)the National Science and Technology Basic Resources Survey Program of China (2019FY101304) to Baoru Sun。
文摘With the development of agricultural technology to meet the growing demands of a rapidly increasing population and economic development,intensive agriculture practices have been widely adopted globally. However,this intensification has resulted in adverse consequences for soil structure due to intensified farming activities and increased usage of heavy farm machinery.Of particular concern is soil compaction, which leads to the degradation of physical, chemical and biological properties of the soil. Soil compaction negatively impacts crop growth, reduces yields and poses a significant threat to food security and the overall sustainability of agricultural systems.Recognizing these challenges, this review aims to deepen understanding of the factors contributing to soil compaction and to develop effective mitigation strategies. By doing so, it is intended to attenuate the adverse impacts of soil compaction, improve soil structure, increase crop yield and ultimately enhance the sustainability of agricultural practices.
基金supported by the National Natural Science Foundation of China(No.52173093)Peking University Ge Li and Ning Zhao Life Science Research Fund for Young Scientists.
文摘The short lifespan of most commercial plastics as disposables and the failure to adequately address the end-of-life issues of synthetic polymers have led to outrageous global plastic pollution and resource depletion.To solve the problem,one of the most effective strategies is to develop circular polymers and thus establish a new circular material economy.Polymers from ring-opening polymerization of five-membered(thio)lactones contribute greatly to this field due to their excellent material performance and recyclability.The emerging topic emphasizes on the monomer design strategies based on five-membered(thio)lactones,and compares the thermal and mechanical properties and depolymerizability of the resulting polymers with different structures.
基金grants from the National High Technology Research and Development Program of China,the National Program on Key Basic Research Project of China,the National Natural Science Foundation of China,Guangdong Innovative Research Team Program,the Ministry of Agriculture of China
文摘A high-density single nucleotide polymorphism (SNP) array is critically important for geneticists and molecu- lar breeders. With the accumulation of huge amounts of genomic re-sequencing data and available technologies for accurate SNP detection, it is possible to design high-density and high-quality rice SNP arrays. Here we report the devel- opment of a high-density rice SNP array and its utility. SNP probes were designed by screening more than 10 000 000 SNP loci extracted from the re-sequencing data of 801 rice varieties and an array named RiceSNP50 was produced on the Illumina Infinium platform. The array contained 51 478 evenly distributed markers, 68% of which were within genic regions. Several hundred rice plants with parent/F1 relationships were used to generate a high-quality cluster file for accurate SNP calling. Application tests showed that this array had high genotyping accuracy, and could be used for dif- ferent objectives. For example, a core collection of elite rice varieties was clustered with fine resolution. Genome-wide association studies (GWAS) analysis correctly identified a characterized QTL. Further, this array was successfully used for variety verification and trait introgression. As an accurate high-throughput genotyping tool, RiceSNP50 will play an important role in both functional genomics studies and molecular breeding.
基金the 1.3.5 Project for Disciplines of Excellence from West China Hospital of Sichuan University(No.ZYGD18027)。
文摘Objective:Safe and effective anticoagulation is essential for hemodialysis patients who are at high risk of bleeding.The purpose of this trial is to evaluate the effectiveness and safety of two-stage regional citrate anticoagulation(RCA)combined with sequential anticoagulation and standard calcium-containing dialysate in intermittent hemodialysis(IHD)treatment.Methods:Patients at high risk of bleeding who underwent IHD from September 2019 to May 2021 were prospectively enrolled in 13 blood purification centers of nephrology departments,and were randomly divided into RCA group and saline flushing group.In the RCA group,0.04 g/mL sodium citrate was infused from the start of the dialysis line during blood draining and at the venous expansion chamber.The sodium citrate was stopped after 3 h of dialysis,which was changed to sequential dialysis without anticoagulant.The hazard ratios for coagulation were according to baseline.Results:A total of 159 patients and 208 sessions were enrolled,including RCA group(80 patients,110 sessions)and saline flushing group(79 patients,98 sessions).The incidence of severe coagulation events of extracorporeal circulation in the RCA group was significantly lower than that in the saline flushing group(3.64%vs.20.41%,P<0.001).The survival time of the filter pipeline in the RCA group was significantly longer than that in the saline flushing group((238.34±9.33)min vs.(221.73±34.10)min,P<0.001).The urea clearance index(Kt/V)in the RCA group was similar to that in the saline flushing group with no statistically significant difference(1.12±0.34 vs.1.08±0.34,P=0.41).Conclusions:Compared with saline flushing,the two-stage RCA combined with a sequential anticoagulation strategy significantly reduced extracorporeal circulation clotting events and prolonged the dialysis time without serious adverse events.
基金supported by the National Natural Science Foundation of China (No. 41171250,20907011)
文摘The adsorption behavior of 2-mercaptobenzothiazole onto organo-bentonite was investigated. Natural bentonite from Gaozhou in Guangdong Province, China was collected. Organo-bentonite was prepared by intercalation of cetyltrimethyl ammonium bromide into the natural bentonite. The physicochemical properties of the prepared organo-bentonite were characterized by X-ray diffraction, N2 adsorption-desorption isotherm and Fourier transform infrared spectroscopy. The results showed that montmorillonite is the main component of the natural bentonite. The basal spacing of the natural bentonite is 1.47 nm, which increased to 1.98 nm on intercalation with cetyltrimethyl ammonium bromide. Moreover, both the surface area and pore volume increased with intercalation. Clear CH2 stretching (3000-2800 cm-1) and scissoring (1480-1450 cm-1) modes of the intercalated surfactants were observed for organo- bentonite. Compared with the pseudo first-order kinetic model, the pseudo second-order kinetic model is more suitable to describe the adsorption kinetics of 2-mercaptobenzothiazole onto organo-bentonite. The adsorption capacity of 2-mercaptobenzothiazole onto organo-bentonite increased with increasing initial concentration of 2-mercaptobenzothiazole, but decreased with increasing adsorbent dosage. The adsorption isotherm of 2-mercaptobenzothiazole onto organo-bentonite fits well with the Langmuir model. The maximum adsorption capacity of organo-bentonite for 2-mercaptobenzothiazole was 33.61 mg/g, indicating that organo-bentonite is a promising adsorbent for 2-mercaptobenzothiazole.
基金We thank the Microscope Center in Life Science Schoolof Sun Yat-sen University for using their facilities formicroscopic analysis,and Yao-Guang Liu for the CRISPR/Cas9 systemThis work was supported by grants from Major Program of Guangdong Basic and Applied Re-search(grant number 2019B030302006)+3 种基金National Nat-ural Science Foundation of China(grant numbersU1901203 and 31801344)Natural Science Foundation ofGuangdong Province(grant number 2018B030308008)Shenzhen Commission on Innovation and Technology Programs(grant number JCYJ20180507181837997)Guangzhou Science and Technology lnnovation Com-mission(grant number 201804010034).
文摘Pollen exine contains complex biopolymers of aliphatic lipids and phenolics.Abnormal development of pollen exine often leads to plant sterility.Molecular mechanisms regulating exine formation have been studied extensively but remain ambiguous.Here we report the analyses of three GDSL esterase/lipase protein genes,OsGELP34,OsGELP110,and OsGELP115,for rice exine for-mation.OsGELP34 was identified by cloning of a male sterile mutant gene.OsGELP34 encodes an endoplasmic reticulum protein and was mainly expressed in anthers during pollen exine formation.osgelp34 mutant displayed abnormal exine and altered expression of a number of key genes required for pollen development.OsGELP110 was previously identified as a gene differentially expressed in meiotic anthers.OsGELP110 was most homologous to OsGELP115,and the two genes showed similar gene expression patterns.Both OsGELP110 and OsGELP115 proteins were localized in peroxisomes.Individual knockout of OsGELP110 and OsGELP115 did not affect the plant fertility,but double knockout of both genes altered the exine structure and rendered the plant male sterile.OsGELP34 is distant from OsGELP110 and OsGELP115 in sequence,and osgelp34 and osgelp110/osgelp115 mutants were different in anther morphology despite both were male sterile.These results suggested that OsGELP34 and OsGELP110/OsGELP115 catalyze different compounds for pollen exine development.
基金This work was supported by the Major Program of Guangdong Basic and Applied Research(2019B030302006)National Natural Science Foundation of China(U1901203,31801344,andU1704232)+3 种基金Natural Science Foundation of Guangdong Province(2018B030308008,2017A030313104,and 2018A0303130270)Shenzhen Commission on Innovation and Technology Programs(JCYJ20180507181837997)China Postdoctoral Science Foundation(2019M652938)the Innovation Project of Graduate School of South China Normal Uni-versity(2017LKXM011).
文摘Pollen grains are covered by exine that protects the pollen from stress and facilitates pollination.Here we isolated a male sterile mutant s13283 in rice exhibiting aborted pollen with abnormal exine and defective aperture.The mutant gene encodes a novel plasma membrane-localized legume-lectin receptor kinase that we named OsLecRK-S.7.OsLecRK-S.7 was expressed at different levels in all tested tissues and throughout anther development.In vitro kinase assay showed OsLecRK-S.7 capable of autophosporylation.Mutation in s13283(E560K)and mutation of the conserved ATP binding site(K418E)both knocked out the kinase activity.Mass spectrometry showed Thr376,Ser378,Thr386,Thr403,and Thr657 to be the autophosphorylation sites.Mutation of individual autophosphorylation site affected the in vitro kinase activity to different degrees,but did not abolish the gene function in fertility complementation.oslecrk-s.7 mutant plant overexpressing OsLecRK-S.7 recovered male fertility but showed severe growth retardation with reduced number of tillers,and these phenotypes were abolished by E560K or K418E mutation.The results indicated that OsLecRK-S.7 was a key regulator of pollen development.
基金supported by the National Natural Science Foundation of China(Nos.41171250,20907011,and 41401356)the Natural Science Foundation of Guangdong Province,China(No.2014A030313702)。
文摘Lignin-degrading enzymes secreted by white rot fungi play an important role in the degradation of lignin and persistent organic pollutants(POPs).In this study,effect of environmental C/N ratio on the activities of lignin-degrading enzymes,lignin peroxide(Li P)and manganese peroxidase(Mn P),produced by Phanerochaete chrysosporium,a white rot fungus,was investigated.Glucose was used as C source,and ammonium tartrate of different concentrations was used as N source to provide different C/N ratios.Relationships between Li P and Mn P activities and environmental C/N ratio were explored.The results showed that the higher the N source concentration,the faster the mycelium pellets aged.The faster the mycelium dry weight increased,the higher the Li P and Mn P activities.A high C/N ratio was a necessary condition for the secretion of Li P or Mn P.In addition,mycelium dry weight essentially affected enzyme activities.In the 122 C/N ratio and 50 C/N ratio treatments,mycelium dry weight essentially affected Mn P activity and both Li P and Mn P activities,respectively.
基金supported by the public welfare projects from MEPPRC (No. 201409010)
文摘PM(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM(2.5) concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM(2.5) pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days(daily PM32.5 concentrations &gt; 250 μg/mand visibility &lt; 3 km) than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO-3/SO2-4,stationary sources are still the dominant source of PM(2.5) and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days.Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources(i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust,vehicle, and industry) of PM(2.5) were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively.Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode(Jan 1-9, 2015) and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM(2.5) in the study area was aggravated.
基金This work was supp orted by the Nationa l Key Research and Development Plan Program(2016YFD0100406 and 2016YFD0101801)National Natural Science Foundation of China(U1901203,31901532,and U1704232)+3 种基金Natural Science Foundation of Guangdong Province(2018B030308008)Shenzhen Commission on Innovation and Technology Programs(JCYJ20180507181837997)China Postdoctoral Science Foundation(2019M652938)Natural Science Foundation of Fujian Province(2017J01427)。
文摘Large-scale production of male sterile seeds can be achieved by introducing a fertility-restoration gene linked with a pollen-killer gene into a recessive male sterile mutant.We attempted to construct this system in rice by using a late-stage pollen-specific(LSP)promoter driving the expression of maizeα-amylase gene ZM-AA1.To obtain such promoters in rice,we conducted comparative RNA-seq analysis of mature pollen with meiosis anther,and compared this with the transcriptomic data of various tissues in the Rice Expression Database,resulting in 269 candidate LSP genes.Initial test of nine LSP genes showed that only the most active OsLSP3 promoter could drive ZM-AA1 to disrupt pollen.We then analyzed an additional 22 LSP genes and found 12 genes stronger than OsLSP3 in late-stage anthers.The promoters of OsLSP5 and OsLSP6 showing higher expression than OsLSP3 at stages 11 and 12 could drive ZM-AA1 to inactivate pollen,while the promoter of OsLSP4 showing higher expression at stage 12 only could not drive ZM-AA1 to disrupt pollen,suggesting that strong promoter activity at stage 11 was critical for pollen inactivation.The strong pollen-specific promoters identified in this study provided valuable tools for genetic engineering of rice male sterile system for hybrid rice production.
基金CAMS Innovation Fund for Medical Sciences(CIFMS)(2016-I2M-1-008)The Capital Health Research and Development of Special(2016-2-40114)+1 种基金Public Welfare Scientific Research Project of China(201402012)Golden Brige Engineering Seed Found of Beijing Association for Science and Technology(JQ17032).
文摘Selective immunoglobulin A deficiency(SIgAD)is considered to be the most common human primary immune-deficiency disease in the world.However,the incidence in China is obviously lower than Caucasian races.The definition of SIgAD has changed over time with the progress of people’s understanding.The scientific community did not reach a consensus on the definition until 1999.As a result,many previously reported cases need to be excluded under the current definition.SIgAD can lead to several spectra of diseases including infections and autoimmune diseases.We retrospectively summarized the SIgAD patients in Peking Union Medical College Hospital(PUMCH),and summarized the Chinese SIgAD reported in China and abroad in past 40 years.Fourty three SIgAD patients were confirmed in the study,in which 9 were healthy without clinical symptoms.Of the 34 patients with clinical symptoms,recurrent infections were found in 29(85.3%)patients;13(38.2%)patients were with autoimmune diseases;6(17.6%)cases had allergic symptoms;3 patients(8.8%)were with tumors,only one case(2.9%)had a family history.Compared with other countries,sIgAD patients in China showed similar symptoms,but the rate of recurrent infections and autoimmune diseases were higher than some other countries;most of the allergic symptoms are drug allergy,different with the allergic sequelae reported in other countries,such as asthma,rhinitis,food allergy and atopic dermatitis;and it is rare to have family history in Chinese patients.We also figured out that more female SIgAD patients tend to have more autoimmune diseases than men(P=0.039).