Hylocereus polyrhizus,also known as pitaya or dragon fruit,is a climbing cactus grown worldwide because of its excellent performance under drought stress and appealing red-purple fruits.In practice,accelerating flower...Hylocereus polyrhizus,also known as pitaya or dragon fruit,is a climbing cactus grown worldwide because of its excellent performance under drought stress and appealing red-purple fruits.In practice,accelerating flower formation and inducing more flowers usually result in higher yield.However,the genes for this purpose have not been well characterized in pitaya.Previously,FLOWERING BHLHs(FBHs)have been identified as positive regulators of flower formation.In the present work,a total of eight FBHs were identified in pitaya.This is a greater number than in beet and spinach,possibly because of the recent whole-genome duplication that occurred in the pitaya genome.The phylogenetic tree indicated that the FBHs could be divided into three groups.In TYPEⅡ,the genes of Caryophyllales encode atypical FBHs and are generated by dispersed duplication.The K_(a)/K_(s) ratios indicated that HpFBHs are under purifying selection.Promoter and expression analysis of HpFBHs revealed that they are spatiotemporally activated in flower-related tissues and responsive to multiple abiotic stresses.These results indicated that HpFBHs are involved in the flower formation of pitaya.Therefore,typical HpFBH1/3 from TYPEⅡI and an atypical HpFBH8 from TYPEⅡwere selected for functional verification.HpFBH3 was found to heterodimerize with HpFBH1 in the nucleus using subcellular localization,yeast two-hybrid and luciferase complementation assays.With bioinformatic analysis,all HpFBHs were predicted to transactivate downstream genes via binding to the E-boxes,which were frequently detected in the promoters of HpCOs,HpFTs and HpSOC1s.RNA-Seq datasets showed that these flowering accelerators were expressed in coordination with HpFBH3.Yeast one-hybrid and dual-luciferase reporter assays further verified that HpFBH3 transactivated HpCO7 by selectively binding to the E-boxes in the promoter.Moreover,ectopic overexpression of HpFBH3 accelerated flower formation in Arabidopsis.In summary,this study systematically characterized the typical HpFBHs,especially HpFBH3,as positive regulators of flower formation,which could be target genes for the genetic improvement of pitaya.展开更多
[Objective] This study was conducted to breed excellent-quality high-yield lines of pink flesh pitaya. [Method] 156 seedling progenies of ＇Conghua Zhixing＇ pink flesh pitaya cultivar were cultivated. Then the growth...[Objective] This study was conducted to breed excellent-quality high-yield lines of pink flesh pitaya. [Method] 156 seedling progenies of ＇Conghua Zhixing＇ pink flesh pitaya cultivar were cultivated. Then the growth character, the high yield character, the fruit economic traits and interior quality were analyzed and compared. [Results] The best one which was marked as 80-1 was selected by the comprehen- sive quality. [Conclusion] It has attractive fruit surface, high quality and high yield.展开更多
[Objective]The aim was to describe the extraction of polysaccharides from pitaya stems.[Method]The hot water,enzyme-assisted and microwave-assisted methods were used,with the microwave-assisted extraction being deemed...[Objective]The aim was to describe the extraction of polysaccharides from pitaya stems.[Method]The hot water,enzyme-assisted and microwave-assisted methods were used,with the microwave-assisted extraction being deemed optimal by general evaluation.[Result]The main factors affecting the yield of polysaccharides in the microwave-assisted extraction,by order of magnitude,were as follows:time >microwave power >temperature;additionally,optimal conditions included a 10 min extraction time,an 80℃ extraction temperature and a microwave setting of 200 W.Using these optimal conditions,the yield of PSPS(Polysaccharides from Pitaya Stems) was 1.42%.After purification,the yield of PSPS was 0.74%.[Conclusion]The PSPS was analyzed by IR,MALDI-TOF-MS and an element analysis technique.It was shown to be a polysaccharide mixture,and the molecular weight was between 3 900 and 4 300 Da.展开更多
Pitaya de mayo (<i>Stenocereus pruinosus</i>) exportation is considered feasible especially to the United States of America (USA) using the adequate preservation and transportation techniques. One of the e...Pitaya de mayo (<i>Stenocereus pruinosus</i>) exportation is considered feasible especially to the United States of America (USA) using the adequate preservation and transportation techniques. One of the exportation requirements is that pitayas, as well as any other tropical fruits, have to be free from Mexican fruit fly contamination and certified by the Food National Sanitary, Iniquity, and Quality Service. This review proved that this fruit is not attacked by the Mexican fruit fly <i>A. ludens</i> or any other Anastrepha species. The fruit fly may <span>be found in some States of Mexican Republic such as some tropical regions bu</span>t not in the semi-arid regions where cacti fruits are grown.展开更多
With the expansion of cultivation scale,pitaya diseases are gradually increasing.Traditionally relying on human observation to judge the disease is limited by the skills and experience of the observer,which cannot gua...With the expansion of cultivation scale,pitaya diseases are gradually increasing.Traditionally relying on human observation to judge the disease is limited by the skills and experience of the observer,which cannot guarantee the accuracy and real-time of the judgment,and consumes much manpower and time.In this study,by collecting,segmenting,and labeling images of 4 main diseases of pitaya in the field,an image database of main diseases of pitaya in the field was constructed to provide a basis for computer image recognition of pitaya diseases.Thereby,it benefits reducing manual error and improving the accuracy and real-time of disease identification for agricultural production,but also lays a foundation for the future development of intelligent agriculture.展开更多
With the adjustment of the tropical and subtropical fruit industry organizations in southern China, the Hylocereus undatus(pitaya) industry is growing rapidly in subtropical Guangxi and other places. Guangxi is also t...With the adjustment of the tropical and subtropical fruit industry organizations in southern China, the Hylocereus undatus(pitaya) industry is growing rapidly in subtropical Guangxi and other places. Guangxi is also the largest natural selenium-rich region in the country, and selenium-enriched pitaya is increasingly sought after by the general public. This paper described in detail the selection of selenium-enriched pitaya production fields, key planting techniques and core selenium enrichment techniques, with a view to providing technical guidance for the standardized production of selenium-enriched pitaya and providing technical support for improving the quality and efficiency of pitaya production in natural selenium-rich areas.展开更多
Alginate is a widely used polymer matrix in food industry since it allows formation of spherical, soft, and strong membranes adequate for encapsulation of a large amount of products, including food. The flow rate of a...Alginate is a widely used polymer matrix in food industry since it allows formation of spherical, soft, and strong membranes adequate for encapsulation of a large amount of products, including food. The flow rate of alginate solutions and the permeability of the capsules were evaluated within an acidic-low acidic pH range and different alginate concentrations. In solutions adjusted at different pH （3.0 to 7.0） with concentrations of alginate of 0.8, 1.0, and 1.2% w/v, flow rates at 20 ℃ were 6.95 to 10.00, 4.54-5.35, and 2.60-2.80 mL sl, respectively. Permeability of the capsules was evaluated in terms of the diffusion of H＋ions （expressed as pH） and soluble solids （~Brix）. Meanwhile both diffusions were minor at 4.0 〈 pH 〈 7.0 and were significantly superior at more acidic pH （P 〈 0.05）, alginate concentration did not present significant effect. Yellow, purple, and red juices from Stenocereus spp. fruits （pitayas） were encapsulated using 1.0% of alginate and stored with isotonic solution （3 mL g^-1） at 4 ℃ in the dark. The capsules were spherical with diameter between 4.59 and 470 mm, weight from 82.60 to 97.50 rag, and volume of 0.075-0.098 mL. Pigment （total betalains content） diffusion reached equilibrium at 24 h of storage, at which point retentions of total betalains in the yellow, purple, and red capsules were 87.79, 96.13, and 85.13%, respectively. Also, changes in the color of the capsules were observed during storage.展开更多
Pitaya is an important perennial herbaceous fruit tree.The color of fruit determines pitaya nutritive(and attractive)value,which is considered as an important objective in breeding improvement.In this study,we reporte...Pitaya is an important perennial herbaceous fruit tree.The color of fruit determines pitaya nutritive(and attractive)value,which is considered as an important objective in breeding improvement.In this study,we reported the first telomere-to-telomere(T2T)gap-free genome of“Shuangse No.1”pitaya(Hylocereus polyrhizus;red peel).Two high-quality genomes for“Dahong”(H.polyrhizus;red peel)and“Honghuaqinglong”(H.stenopterus;stay-green)were further assembled,aiming to explore the genetic diversity of pitaya genomes.In further analysis,we noticed a high proportion of viral contamination in pitaya tissues,which hindered the efficient utilization of transcriptomic data.To address this issue,we analyzed 111 pitaya transcriptome data from different geographic regions to characterize and separate viral components.Then we developed an efficient,novel,and universal transcript purification system for pitaya transcriptomes by applying it to 27 samples from different tissues and species,thereby enhancing the utility for transcriptomic and broader biological research.Combining the purified transcriptomic data with comparative genomic analyses,we identified HuERF72,a transcription factor(TF)that potentially regulates chlorophyll degradation in pitaya.Interaction assays and plant transformation elucidated that HuERF72 acts as a repressive TF by directly binding to the promoter of HuSGR1,a key structural gene in the chlorophyll degradation pathway.This study provides high-quality genomic resources and novel methodologies for molecular investigations in pitaya.Additionally,the proposed regulatory network advances our understanding of the transcriptional regulatory mechanisms underlying chlorophyll degradation,offering valuable insights into the genetic improvement of pitaya.展开更多
Soluble sugar is one of the most important factors affecting fruit flavor and quality.Here,we report the identification of two Dof(DNA-binding with one finger)transcription factors termed HpDof1.7 and HpDof5.4 and the...Soluble sugar is one of the most important factors affecting fruit flavor and quality.Here,we report the identification of two Dof(DNA-binding with one finger)transcription factors termed HpDof1.7 and HpDof5.4 and their roles in influencing sugar accumulation in pitayas.HpDof1.7 and HpDof5.4 share a similar expression pattern with sugar metabolism-related genes HpSuSy1 and HpINV2,and sugar transporter genes HpTMT2 and HpSWEET14 during pitayas maturation,and their expression pattern was also consistent with the accumulation of glucose and fructose,which were the predominant sugars in pitayas.HpDof1.7 and HpDof5.4 were both typical nucleus-localized proteins with trans-activation ability.Gel mobility shift assay revealed that HpDof1.7 and HpDof5.4 were bound to promoters of HpSuSy1,HpINV2,HpTMT2 and HpSWEET14.Finally,transient expression assays in tobacco leaves showed that HpDof1.7 and HpDof5.4 increased the activities of HpSuSy1,HpINV2,HpTMT2 and HpSWEET14 promoters,thus facilitating sugar accumulation by transcriptionally enhancing sugar metabolic pathway genes.Our findings provide a new perspective on the regulatory mechanisms of Dof transcription factors in sugar accumulation and pitaya fruit quality formation.展开更多
Objectives:Myeloblastosis(MYB)proteins,recognized as crucial transcriptional regulators,play an integral role in orchestrating the range of plant colors.Materials and Methods:Pitaya(Hylocereus spp.),a distinctive comm...Objectives:Myeloblastosis(MYB)proteins,recognized as crucial transcriptional regulators,play an integral role in orchestrating the range of plant colors.Materials and Methods:Pitaya(Hylocereus spp.),a distinctive commercially cultivated fruit,stands apart due to its unique betalains,water-soluble nitrogen-enriched pigments that confer its vibrant hues.Although betalain biosynthesis has been extensively explored,the potential infuence of co-activators that might disrupt pigment production remains relatively unexplored.Results:In this study,we found that HuMYB9,an R2R3-MYB repressor,exhibited a remarkable decreasing during pitaya maturation.Sequence alignment analyses showed conserved R2 and R3 domains within the C-terminal of HuMYB9.HuMYB9’s regulatory activities were found to be nuclear localized and it interacted with specifc elements within the promoters of HuDODA1,HuADH1,and HuCYP76AD1-1,thus infuencing the transcriptional activities in vitro.HuMYB9 transiently downregulated the expression of key betalain biosynthetic genes with a corresponding effect on the levels of pitaya pulp betalains.Conclusions:Our results suggest that HuMYB9 operates as a suppressor,specifcally downregulating the expression of HuCYP76AD1-1,HuDODA1,and HuADH,thereby modulating betalain biosynthesis in pitaya.Collectively,our fndings provide invaluable insights into the regulation of betalain accumulation in pitaya.展开更多
The pitaya peel powder was mixed with 50%ethanol solution at a ratio of 1:10(w/v)for 24 h to obtain the pitaya peel ethanol extract(E).The extract was further fractionated with supercritical carbon dioxide(SC-CO_(2))u...The pitaya peel powder was mixed with 50%ethanol solution at a ratio of 1:10(w/v)for 24 h to obtain the pitaya peel ethanol extract(E).The extract was further fractionated with supercritical carbon dioxide(SC-CO_(2))under the operating conditions:temperature 40℃ and pressure of 30,25,20 or 10 MPa into R,F1,F2 or F3 fractions,respectively.Our results confirmed SC-CO_(2)fractionation significantly influenced the distribution of phenolic compounds,polysaccharides and betalains in fractions and thus affected their physico-chemical properties.Bioactive compounds majorly distributed in F1;consequently,DPPH and ABTS radicals scavenging activities of F1 are higher than those of other fractions.The IC_(50)values of DPPH and ABTS scavenging ability were 0.78 mg/mL and 0.69 mg/mL for F1 fraction,respectively.Linear structure model analysis showed that the scavenging activities of the both free radicals were positively related to phenolic compounds and polysaccharide components.The strong red-orange color spectrum of E was simultaneously fractionated into the red-orange color F1,the bright red color of F2 and F3 and the vivid orange color of R.展开更多
仙人掌X病毒(cactuSviruSX,CVX)严重威胁世界火龙果产业的发展。为实现对该病毒的定量检测,本研究根据CVX外壳蛋白(CP)的保守序列设计特异性引物CVX-F/-R,建立了引物浓度150 nmol/L,退火温度62℃的SYBR Green I实时荧光定量PCR检测方法...仙人掌X病毒(cactuSviruSX,CVX)严重威胁世界火龙果产业的发展。为实现对该病毒的定量检测,本研究根据CVX外壳蛋白(CP)的保守序列设计特异性引物CVX-F/-R,建立了引物浓度150 nmol/L,退火温度62℃的SYBR Green I实时荧光定量PCR检测方法。该引物扩增效率为97.38%,R^(2)为0.9965,对标准品的检测极限浓度为8×10^(2)拷贝/μL,其灵敏度是普通PCR的100倍。对火龙果不同组织中CVX的相对表达量进行检测发现,病毒在花丝中的含量最高,之后依次为花萼、花瓣、嫩枝、老枝和根。对采自贵州黔南州的40份火龙果样品进行检测,共检测出32份阳性样品。上述结果表明,本研究建立的实时荧光定量PCR特异性强、灵敏度高,为今后CVX的检测提供了重要的技术补充。展开更多
基金supported by the National Natural Science Foundation of China(32160681 and 32060663)the National Guidance Foundation for Local Science and Technology Development of China(2023-009)+1 种基金the Guizhou Provincial Basic Research Program(Natural Science)(ZK[2022]YB132)the Foundation of Postgraduate of Guizhou Province,China(YJSKYJJ[2021]057)。
文摘Hylocereus polyrhizus,also known as pitaya or dragon fruit,is a climbing cactus grown worldwide because of its excellent performance under drought stress and appealing red-purple fruits.In practice,accelerating flower formation and inducing more flowers usually result in higher yield.However,the genes for this purpose have not been well characterized in pitaya.Previously,FLOWERING BHLHs(FBHs)have been identified as positive regulators of flower formation.In the present work,a total of eight FBHs were identified in pitaya.This is a greater number than in beet and spinach,possibly because of the recent whole-genome duplication that occurred in the pitaya genome.The phylogenetic tree indicated that the FBHs could be divided into three groups.In TYPEⅡ,the genes of Caryophyllales encode atypical FBHs and are generated by dispersed duplication.The K_(a)/K_(s) ratios indicated that HpFBHs are under purifying selection.Promoter and expression analysis of HpFBHs revealed that they are spatiotemporally activated in flower-related tissues and responsive to multiple abiotic stresses.These results indicated that HpFBHs are involved in the flower formation of pitaya.Therefore,typical HpFBH1/3 from TYPEⅡI and an atypical HpFBH8 from TYPEⅡwere selected for functional verification.HpFBH3 was found to heterodimerize with HpFBH1 in the nucleus using subcellular localization,yeast two-hybrid and luciferase complementation assays.With bioinformatic analysis,all HpFBHs were predicted to transactivate downstream genes via binding to the E-boxes,which were frequently detected in the promoters of HpCOs,HpFTs and HpSOC1s.RNA-Seq datasets showed that these flowering accelerators were expressed in coordination with HpFBH3.Yeast one-hybrid and dual-luciferase reporter assays further verified that HpFBH3 transactivated HpCO7 by selectively binding to the E-boxes in the promoter.Moreover,ectopic overexpression of HpFBH3 accelerated flower formation in Arabidopsis.In summary,this study systematically characterized the typical HpFBHs,especially HpFBH3,as positive regulators of flower formation,which could be target genes for the genetic improvement of pitaya.
基金Supported by Guangdong Science and Technology Plan Project(2010B-020410002015)Guangzhou Science and Technology Plan Project(2014Y2-00164)~~
文摘[Objective] This study was conducted to breed excellent-quality high-yield lines of pink flesh pitaya. [Method] 156 seedling progenies of ＇Conghua Zhixing＇ pink flesh pitaya cultivar were cultivated. Then the growth character, the high yield character, the fruit economic traits and interior quality were analyzed and compared. [Results] The best one which was marked as 80-1 was selected by the comprehen- sive quality. [Conclusion] It has attractive fruit surface, high quality and high yield.
文摘[Objective]The aim was to describe the extraction of polysaccharides from pitaya stems.[Method]The hot water,enzyme-assisted and microwave-assisted methods were used,with the microwave-assisted extraction being deemed optimal by general evaluation.[Result]The main factors affecting the yield of polysaccharides in the microwave-assisted extraction,by order of magnitude,were as follows:time >microwave power >temperature;additionally,optimal conditions included a 10 min extraction time,an 80℃ extraction temperature and a microwave setting of 200 W.Using these optimal conditions,the yield of PSPS(Polysaccharides from Pitaya Stems) was 1.42%.After purification,the yield of PSPS was 0.74%.[Conclusion]The PSPS was analyzed by IR,MALDI-TOF-MS and an element analysis technique.It was shown to be a polysaccharide mixture,and the molecular weight was between 3 900 and 4 300 Da.
文摘Pitaya de mayo (<i>Stenocereus pruinosus</i>) exportation is considered feasible especially to the United States of America (USA) using the adequate preservation and transportation techniques. One of the exportation requirements is that pitayas, as well as any other tropical fruits, have to be free from Mexican fruit fly contamination and certified by the Food National Sanitary, Iniquity, and Quality Service. This review proved that this fruit is not attacked by the Mexican fruit fly <i>A. ludens</i> or any other Anastrepha species. The fruit fly may <span>be found in some States of Mexican Republic such as some tropical regions bu</span>t not in the semi-arid regions where cacti fruits are grown.
基金the Key Research and Development Project of Hainan Province of China(ZDYF2017066)Natural Science Foundation of Hainan Province of China(619MS028)the Research on Education and Teaching Reform of Hainan University(hdjy1954)。
文摘With the expansion of cultivation scale,pitaya diseases are gradually increasing.Traditionally relying on human observation to judge the disease is limited by the skills and experience of the observer,which cannot guarantee the accuracy and real-time of the judgment,and consumes much manpower and time.In this study,by collecting,segmenting,and labeling images of 4 main diseases of pitaya in the field,an image database of main diseases of pitaya in the field was constructed to provide a basis for computer image recognition of pitaya diseases.Thereby,it benefits reducing manual error and improving the accuracy and real-time of disease identification for agricultural production,but also lays a foundation for the future development of intelligent agriculture.
基金Supported by Guangxi Innovation-driven Development Science and Technology Major Project(GK AA17202026,GK AA17202037)Scientific Research and Technology Development Program of Nanning City(20182100)+2 种基金Guangxi Key Research and Development Program(GK AB16380164)Guangxi Selenium-enriched Crop Experiment Station(GTS2016011)Fundamental Scientific Research Fund of Guangxi Academy of Agricultural Sciences(GNK 2017YZ03)
文摘With the adjustment of the tropical and subtropical fruit industry organizations in southern China, the Hylocereus undatus(pitaya) industry is growing rapidly in subtropical Guangxi and other places. Guangxi is also the largest natural selenium-rich region in the country, and selenium-enriched pitaya is increasingly sought after by the general public. This paper described in detail the selection of selenium-enriched pitaya production fields, key planting techniques and core selenium enrichment techniques, with a view to providing technical guidance for the standardized production of selenium-enriched pitaya and providing technical support for improving the quality and efficiency of pitaya production in natural selenium-rich areas.
文摘Alginate is a widely used polymer matrix in food industry since it allows formation of spherical, soft, and strong membranes adequate for encapsulation of a large amount of products, including food. The flow rate of alginate solutions and the permeability of the capsules were evaluated within an acidic-low acidic pH range and different alginate concentrations. In solutions adjusted at different pH （3.0 to 7.0） with concentrations of alginate of 0.8, 1.0, and 1.2% w/v, flow rates at 20 ℃ were 6.95 to 10.00, 4.54-5.35, and 2.60-2.80 mL sl, respectively. Permeability of the capsules was evaluated in terms of the diffusion of H＋ions （expressed as pH） and soluble solids （~Brix）. Meanwhile both diffusions were minor at 4.0 〈 pH 〈 7.0 and were significantly superior at more acidic pH （P 〈 0.05）, alginate concentration did not present significant effect. Yellow, purple, and red juices from Stenocereus spp. fruits （pitayas） were encapsulated using 1.0% of alginate and stored with isotonic solution （3 mL g^-1） at 4 ℃ in the dark. The capsules were spherical with diameter between 4.59 and 470 mm, weight from 82.60 to 97.50 rag, and volume of 0.075-0.098 mL. Pigment （total betalains content） diffusion reached equilibrium at 24 h of storage, at which point retentions of total betalains in the yellow, purple, and red capsules were 87.79, 96.13, and 85.13%, respectively. Also, changes in the color of the capsules were observed during storage.
基金supported by the Natural Science Foundation of Guangdong Province(2025A1515012561 and 2024A1515013152)National Natural Science Foundation of China(W2433071 and 31972367)Provincial Rural Revitalization Strategy Special Project of Guangdong in 2024(2024-NPY-00-030).
文摘Pitaya is an important perennial herbaceous fruit tree.The color of fruit determines pitaya nutritive(and attractive)value,which is considered as an important objective in breeding improvement.In this study,we reported the first telomere-to-telomere(T2T)gap-free genome of“Shuangse No.1”pitaya(Hylocereus polyrhizus;red peel).Two high-quality genomes for“Dahong”(H.polyrhizus;red peel)and“Honghuaqinglong”(H.stenopterus;stay-green)were further assembled,aiming to explore the genetic diversity of pitaya genomes.In further analysis,we noticed a high proportion of viral contamination in pitaya tissues,which hindered the efficient utilization of transcriptomic data.To address this issue,we analyzed 111 pitaya transcriptome data from different geographic regions to characterize and separate viral components.Then we developed an efficient,novel,and universal transcript purification system for pitaya transcriptomes by applying it to 27 samples from different tissues and species,thereby enhancing the utility for transcriptomic and broader biological research.Combining the purified transcriptomic data with comparative genomic analyses,we identified HuERF72,a transcription factor(TF)that potentially regulates chlorophyll degradation in pitaya.Interaction assays and plant transformation elucidated that HuERF72 acts as a repressive TF by directly binding to the promoter of HuSGR1,a key structural gene in the chlorophyll degradation pathway.This study provides high-quality genomic resources and novel methodologies for molecular investigations in pitaya.Additionally,the proposed regulatory network advances our understanding of the transcriptional regulatory mechanisms underlying chlorophyll degradation,offering valuable insights into the genetic improvement of pitaya.
基金unded by the Key Science and Technology Planning Project of Guangzhou(No.201904020015)the Science and Technology Program of Guangzhou(No.202002020060)the Science and Technology Program of Zhanjiang(No.2019A01003),China.
文摘Soluble sugar is one of the most important factors affecting fruit flavor and quality.Here,we report the identification of two Dof(DNA-binding with one finger)transcription factors termed HpDof1.7 and HpDof5.4 and their roles in influencing sugar accumulation in pitayas.HpDof1.7 and HpDof5.4 share a similar expression pattern with sugar metabolism-related genes HpSuSy1 and HpINV2,and sugar transporter genes HpTMT2 and HpSWEET14 during pitayas maturation,and their expression pattern was also consistent with the accumulation of glucose and fructose,which were the predominant sugars in pitayas.HpDof1.7 and HpDof5.4 were both typical nucleus-localized proteins with trans-activation ability.Gel mobility shift assay revealed that HpDof1.7 and HpDof5.4 were bound to promoters of HpSuSy1,HpINV2,HpTMT2 and HpSWEET14.Finally,transient expression assays in tobacco leaves showed that HpDof1.7 and HpDof5.4 increased the activities of HpSuSy1,HpINV2,HpTMT2 and HpSWEET14 promoters,thus facilitating sugar accumulation by transcriptionally enhancing sugar metabolic pathway genes.Our findings provide a new perspective on the regulatory mechanisms of Dof transcription factors in sugar accumulation and pitaya fruit quality formation.
基金supported by the National Natural Science Foundation of China(No.31972367)the Science and Technology Program of Yangjiang(No.yangketong[2021]50)the Provincial Rural Revitalization Strategy Special Project of Guangdong in 2022(No.2022-NPY-00-034),China.
文摘Objectives:Myeloblastosis(MYB)proteins,recognized as crucial transcriptional regulators,play an integral role in orchestrating the range of plant colors.Materials and Methods:Pitaya(Hylocereus spp.),a distinctive commercially cultivated fruit,stands apart due to its unique betalains,water-soluble nitrogen-enriched pigments that confer its vibrant hues.Although betalain biosynthesis has been extensively explored,the potential infuence of co-activators that might disrupt pigment production remains relatively unexplored.Results:In this study,we found that HuMYB9,an R2R3-MYB repressor,exhibited a remarkable decreasing during pitaya maturation.Sequence alignment analyses showed conserved R2 and R3 domains within the C-terminal of HuMYB9.HuMYB9’s regulatory activities were found to be nuclear localized and it interacted with specifc elements within the promoters of HuDODA1,HuADH1,and HuCYP76AD1-1,thus infuencing the transcriptional activities in vitro.HuMYB9 transiently downregulated the expression of key betalain biosynthetic genes with a corresponding effect on the levels of pitaya pulp betalains.Conclusions:Our results suggest that HuMYB9 operates as a suppressor,specifcally downregulating the expression of HuCYP76AD1-1,HuDODA1,and HuADH,thereby modulating betalain biosynthesis in pitaya.Collectively,our fndings provide invaluable insights into the regulation of betalain accumulation in pitaya.
基金support(MOST 108-2221-E415-014)from the Ministry of Science and Technology,Taiwan,ROC is gratefully acknowledged。
文摘The pitaya peel powder was mixed with 50%ethanol solution at a ratio of 1:10(w/v)for 24 h to obtain the pitaya peel ethanol extract(E).The extract was further fractionated with supercritical carbon dioxide(SC-CO_(2))under the operating conditions:temperature 40℃ and pressure of 30,25,20 or 10 MPa into R,F1,F2 or F3 fractions,respectively.Our results confirmed SC-CO_(2)fractionation significantly influenced the distribution of phenolic compounds,polysaccharides and betalains in fractions and thus affected their physico-chemical properties.Bioactive compounds majorly distributed in F1;consequently,DPPH and ABTS radicals scavenging activities of F1 are higher than those of other fractions.The IC_(50)values of DPPH and ABTS scavenging ability were 0.78 mg/mL and 0.69 mg/mL for F1 fraction,respectively.Linear structure model analysis showed that the scavenging activities of the both free radicals were positively related to phenolic compounds and polysaccharide components.The strong red-orange color spectrum of E was simultaneously fractionated into the red-orange color F1,the bright red color of F2 and F3 and the vivid orange color of R.
文摘仙人掌X病毒(cactuSviruSX,CVX)严重威胁世界火龙果产业的发展。为实现对该病毒的定量检测,本研究根据CVX外壳蛋白(CP)的保守序列设计特异性引物CVX-F/-R,建立了引物浓度150 nmol/L,退火温度62℃的SYBR Green I实时荧光定量PCR检测方法。该引物扩增效率为97.38%,R^(2)为0.9965,对标准品的检测极限浓度为8×10^(2)拷贝/μL,其灵敏度是普通PCR的100倍。对火龙果不同组织中CVX的相对表达量进行检测发现,病毒在花丝中的含量最高,之后依次为花萼、花瓣、嫩枝、老枝和根。对采自贵州黔南州的40份火龙果样品进行检测,共检测出32份阳性样品。上述结果表明,本研究建立的实时荧光定量PCR特异性强、灵敏度高,为今后CVX的检测提供了重要的技术补充。
