Litchi has great economic significance as a global fruit crop.However,the advancement of litchi functional genomics has encountered substantial obstacles due to its recalcitrance to stable transformation.Here,we prese...Litchi has great economic significance as a global fruit crop.However,the advancement of litchi functional genomics has encountered substantial obstacles due to its recalcitrance to stable transformation.Here,we present an efficacious Agrobacterium tumefaciens-mediated transformation system in somatic embryos of‘Heiye'litchi.This system was developed through the optimization of key variables encompassing explant selection,A.tumefaciens strain delineation,bacterium concentration,infection duration,and infection methodology.The subsequent validation of the transformation technique in litchi was realized through the ectopic expression of LcMYB1,resulting in the generation of transgenic calli.However,the differentiation of transgenic calli into somatic embryos encountered substantial challenges.To delineate the intricate molecular underpinnings of LcMYB1's inhibitory role in somatic embryo induction,a comprehensive transcriptome analysis was conducted that encompassed embryogenic calli(C),globular embryos(G),and transgenic calli(TC).A total of 1,166 common differentially expressed genes(DEGs)were identified between C-vs.-G and C-vs.-TC.Gene Ontology(GO)annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis revealed that these common DEGs were mostly related to plant hormone signal transduction pathways.Furthermore,RT-qPCR corroborated the pronounced down-regulation of numerous genes that are associated with somatic embryo induction within the transgenic calli.The development of this transformation system provides valuable support for functional genomics research in litchi.展开更多
Litchi chinensis Sonn is widely cultivated in subtropical regions and has an important economic value.A high-density genetic map is a valuable tool for mapping quantitative trait loci(QTL)and marker-assisted breeding ...Litchi chinensis Sonn is widely cultivated in subtropical regions and has an important economic value.A high-density genetic map is a valuable tool for mapping quantitative trait loci(QTL)and marker-assisted breeding programs.In this study,a single nucleotide polymorphism(SNP)-based high-density linkage map was constructed by a genotyping-by-sequencing(GBS)protocol using an F1 population of 178 progenies between two commercial litchi cultivars,‘Ziniangxi’(dwarf)and‘Feizixiao’(vigorous).The genetic map consisted of 3027 SNP markers with a total length of 1711.97 cM in 15 linkage groups(LGs)and an average marker distance of 0.57 cM.Based on this high-density linkage map and three years of phenotyping,a total of 37 QTLs were detected for eight dwarf-related traits,including length of new branch(LNB),diameter of new branch(DNB),length of common petiole(LCP),diameter of common petiole(DCP),length of internode(LI),length of single leaf(LSL),width of single leaf(WSL),and plant height(PH).These QTLs could explain 8.0 to 14.7%(mean=9.7%)of the phenotypic variation.Among them,several QTL clusters were observed,particularly on LG04 and LG11,which might show enrichment for genes regulating the dwarf-related traits in litchi.There were 126 candidate genes identified within the QTL regions,55 of which are differentially expressed genes by RNA-seq analysis between‘Ziniangxi’and‘Feizixiao’.These DEGs were found to participate in the regulation of cell development,material transportation,signal transduction,and plant morphogenesis,so they might play important roles in regulating plant dwarf-related traits.The high-density genetic map and QTLs identification related to dwarf traits can provide a valuable genetic resource and a basis for marker-assisted selection and genomic studies of litchi.展开更多
Objective:To investigate the effect of saponin from the seed of Litchi chinensis Sonn(SLS)on the growth and apoptosis of human kidney epithelial cells(HKC)cultured in high glucose.Methods:HKC were cultured in DMEM/F12...Objective:To investigate the effect of saponin from the seed of Litchi chinensis Sonn(SLS)on the growth and apoptosis of human kidney epithelial cells(HKC)cultured in high glucose.Methods:HKC were cultured in DMEM/F12 medium supplemented with 30 mmol/L glucose and treated with or without SLS.In the normal group,isometric DMEM/F12 medium with 5.5mmol/L glucose was added.The secretion of TGF-β1 and fibronectin(FN)were detected by ELISA.Cell apoptosis was detected by the method of Annexin V-FITC/PI double staining.Western blot was used to detect the level of suppressor of cytokine signaling-1(SOCS-1).Results:The result of ELISA showed that the secretion of TGF-β1 and FN was decreased in SLS groups compared with those in 30 mmol/L glucose treated group(P<0.05).There were more cells apoptosis in 30 mmol/L glucose treated group than that in the normal group(P<0.01).Compared with the 30 mmol/L glucose treated group,the apoptosis of HKC were significantly decreased in SLS groups(P<0.01).Western blot showed that the level of SOCS-1 in high glucose+SLS group was decreased(P<0.01),compared with the high glucose group.Conclusion:SLS can reduce the secretion of TGF-β1 and FN in HKC by reducing the deposition of extracellular matrix.SLS also significantly reduced the apoptosis of HKC by inhibiting the level of SOCS-1.These results suggest the roles of SLS in preventing the progress of glomerular sclerosis.展开更多
Polyamines play an important role in plant response to abiotic stress. S-adenosyl-1-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understan...Polyamines play an important role in plant response to abiotic stress. S-adenosyl-1-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on the shelf life improvement of litchi fruit, SAMDC cDNA isolated from Datura stramonium cloned in pBI121 was introduced into litchi genome by means of Agrobacterium tumefaciens through zygote disc transformation. Transgene and its expression are confirmed by Southern and Northern blot analyses, respectively. Transgenic plants expressing Datura SAMDC produced 1.7- to 2.4-fold higher levels of spermidine and spermine than wildtype plants under normal environmental condition, which indicated that the transgenic litchi presented an enhanced polyamines synthesis compared to wildtype plants. Our results demonstrated clearly that increasing polyamine biosynthesis in plants may be a means of creating improved fruit shelf life germplasm.展开更多
Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-E...Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-Exp1 and Lc-Exp2 , were cloned. Lc-Exp1 and Lc-Exp2 was respectively composed of 531 bp encoding 177 amino acids and 537 bp encoding 179 amino acids. Eight cysteine residues and three tryp-tophan residues, which is supposed to be the characteristics of expansins, are conserved in both Lc-Exp1 and c-Exp2. In addition, the homology between the two expansins is 71. 6% at nucleotide acid sequences and 76.3% at amino acid sequences. The homology of Lc-Exp1 with Fa-Exp2 or Pp-Exp1 was 92.7% or 92.1%, but that of Lc-Exp2 with Fa-Exp2 or Pp-Exp1 was only 77. 4% or 76.3% at amino acid sequences.展开更多
Sucrose synthase(SUS,EC 2.4.1.13)is widely considered as a key enzyme involved in plant sucrose metabolism,and the gene family encoding different SUS isozymes has been identified and characterized in several plant spe...Sucrose synthase(SUS,EC 2.4.1.13)is widely considered as a key enzyme involved in plant sucrose metabolism,and the gene family encoding different SUS isozymes has been identified and characterized in several plant species.However,to date scant information about the SUS genes is available in Litchi chinensis Sonn.Here,we identified five SUS genes in litchi.These Lc SUSs shared high levels of similarity in both nucleotide and amino acid sequences.Their gene structure,phylogenetic relationships,and expression profiles were characterized.Gene structure analysis indicated that the Lc SUSs have similar exon-intron structures.Phylogenetic analysis revealed that the five members could be classified into three groups(LcSUS1 and LcSUS2 in SUSⅡ,LcSUS4 and LcSUS5 in SUSⅢ,and LcSUS3 in SUSⅠ),demonstrating evolutionary conservation in the SUS family across litchi and other plant species.The expression levels of Lc SUSs were investigated via real-time PCR in various tissues and different developmental stages of aril.For tissues and organs,Lc SUSs exhibited distinct but partially redundant expression profiles in litchi,being predominantly expressed in young leaves(sink).During aril development,the expression pattern of LcSUS1 was consistent with the trend of sugar accumulation,indicating it may play important roles in determination of sink strength in aril.Moreover,transcript levels of LcSUS2,LcSUS4,and LcSUS5 varied between cultivars with different hexose/sucrose ratios,which may regulate the sugar composition in aril.Our results provide insights into physiological functions of SUS genes in litchi,especially roles in regulating sugar accumulation in aril.展开更多
Objective: To synthesize and isolate silver and gold nanoparticles from Litchi chinensis leaf methanolic extract, and to evaluate its comparative biological activities including muscles relaxant, analgesic, anti-infla...Objective: To synthesize and isolate silver and gold nanoparticles from Litchi chinensis leaf methanolic extract, and to evaluate its comparative biological activities including muscles relaxant, analgesic, anti-inflammatory and antidiarrheal. Methods: The gold and silver nanoparticles were synthesized by dissolving methanolic extract in gold chloride and silver nitrate solution separately which were confirmed by colour change and UV-Vis spectroscopy, and pellets were collected through centrifugation. Biological activities of the extract were conducted on BALB/c mice through various standard methods and the data were subjected to One-way ANOVA. Results: The colorless gold chloride solution changed to purple soon after the addition of plant extract, demonstrating that the reaction took place and gold ions were reduced to gold nanoparticles, while colorless silver nitrate solution changed to light and dark brown that was indicative of silver nanoparticles. The muscles relaxant activity showed that silver nanoparticles were more effective than gold nanoparticles and methanolic extract in traction test. The analgesic activity showed that silver and gold nanoparticles showed highest percentage decrease in acetic acid induced writhing at the doses of 50, 100 and 150 mg/kg b.w. The highest anti-inflammatory activity was produced by gold nanoparticles followed by silver nanoparticles, while low activity was observed in methanolic leaf extract. Only the crude methanolic extract showed significant antidiarrheal activity as compared to the standard drug atropine sulphate, while antidiarrheal activities of gold and silver nanoparticles were non-significant. Conclusions: The present work concludes that isolated silver and gold nanoparticles from leaf methanolic extract shows strong muscles relaxant, analgesic and anti-inflammatory activities while crude methanolic extract possesses good antidiarrheal activity.展开更多
Being sensitive to climatic conditions,the growth of Litchi chinensis（ lychee） can be greatly affected both in rainy warm winter which is conductive to winter shoot elongation,seriously affecting the formation of fl...Being sensitive to climatic conditions,the growth of Litchi chinensis（ lychee） can be greatly affected both in rainy warm winter which is conductive to winter shoot elongation,seriously affecting the formation of flower buds,and in rainy spring or cold late spring when lychee is flowering,seriously affecting pollination and fruit set. Thus,meteorological conditions play a decisive role in determining the distribution,growth and development,yield formation and quality of lychee. Based on meteorological conditions,some measures can be taken to reduce the impacts of adverse weather and take advantage of favorable weather conditions for the stable and high production of lychee. Therefore,the yield of lychee could be increased by improving the accuracy of weather forecasts and long-term cultivation and management techniques.展开更多
[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determ...[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.展开更多
Litchi(Litchi chinensis Sonn.)is a type of commercially prevalent subtropical and tropical fruit.Since litchi has a highly heterozygous genetic background and a long reproductive cycle,conventional breeding methods(su...Litchi(Litchi chinensis Sonn.)is a type of commercially prevalent subtropical and tropical fruit.Since litchi has a highly heterozygous genetic background and a long reproductive cycle,conventional breeding methods(such as hybridization)have limited ability to nurture new litchi cultivars.Here,an efficient and stable Agrobacterium tumefaciens-mediated genetic transformation of embryogenic callus was established in‘Feizixiao’litchi.Transgenic materials were verified using polymerase chain reaction(PCR)analysis,β-glucuronidase(GUS)assay,and green fluorescent protein(GFP)assay.To implement the technology of the Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)/associated protein 9(CRISPR/Cas9)technology in‘Feizixiao’litchi and verify the validity of these transformation systems,the litchi polyphenol oxidase gene(LcPPO,JF926153)was knocked out.Various categories of mutations,covering base insertions,deletions,and substitutions,were found in transgenic materials via sequence analysis.The transformation system achieved high feasibility and efficiency,and the system of CRISPR/Cas9 was successfully employed to edit genes in‘Feizixiao’litchi.This work provides an essential foundation for investigating the functions of genes and accelerating litchi genetic improvement.展开更多
The regulatory role of calcium in fertility of pollen and pistil under simulated acid rain was investigated. The germination percentage of pollen treated with acid rain of pH 4.5 was 9.42% lower than that of control, ...The regulatory role of calcium in fertility of pollen and pistil under simulated acid rain was investigated. The germination percentage of pollen treated with acid rain of pH 4.5 was 9.42% lower than that of control, and that of pH 3.5, pH 2.5 and pH 1.5 were 22.47%, 45.49% and 71.62%, respectively. Simultaneously, the injury character of pollen was obviously observed when flowers were treated with acid rain of pH 3.5. The difference in fruit setting rate between the female flower treated with acid rain of pH 4.0 and the control was significant at p 〈 0.05. Ca（NO3 ）5 of 0.2-0.4 mmol/L could promote pollen germination under the stress of acid rain. The beneficial function was reduced when calcium concentration surpassed 0.8 mmol/L. Spraying 2 mmol/L Ca（NO3 ）5 reduced the injury of acid rain to pistil and increased fruit-setting rate significantly. The physiological importance of calcium during pollen germination and pistil development was also discussed.展开更多
Fruit and leaf shoot of litchi （Litchi chinensis） infestation by naturally occurring populations of the fruit bprer, Conopomorpha sinensis larvae and C. sinensis parasitization rates were determined in litchi orchar...Fruit and leaf shoot of litchi （Litchi chinensis） infestation by naturally occurring populations of the fruit bprer, Conopomorpha sinensis larvae and C. sinensis parasitization rates were determined in litchi orchards in northern Thailand at high （ca. 1 400 m ASL） and low （ca. 800 m ASL） elevations with different, non-overlapping fruiting seasons. In addition, spray applications of Bacillus thuringiensis var. aizawai, the natural compound spinosad and the chemical pesticide imidacloprid were conducted in the field to test the effects of these agents on C. sinensis fruit infestation rate. Fruit infestation rate and fruit growth, studied in a low elevation orchard, were sigmoidal and showed a highly significant positive correlation （P ≤ 0.01）. Leaf shoot infestation rate in the low elevation orchard decreased in the course of the fruiting season （March until May）, but increased in the high elevation orchard, where no fruits were present within the same period of time. Together, these results indicate that females of C. sinensis clearly prefer fruits over shoots for oviposition. If no fruits are available, which was the case in the high elevation orchard during that time, they are constrained to lay their eggs on shoots. The parasitization rate of C. sinensis larvae in untreated fruits was 54.3%. The parasitoid species were Chelonus chailini （90.8%） and Phanerotoma sp. （9.2%）. In the leaf shoots, C. sinensis was found to be parasitized by Phanerotoma sp. and Apanteles briareus. The applications of the different active agents had no significant effect on C. sinensis fruit infestation compared to the untreated control. Besides the cryptic life of the larvae, this is most probably explained by the fact that C. sinensis has several generations during the fruiting season. Because of the high parasitization rates recorded, an alternative and more effective control measure than the application of pesticides might be the augmentative release of parasitoids.展开更多
基金supported by the National Natural Science Foundation of China(31872066 and 32272663)the Science and Technology Planning Project of Guangzhou,China(2023B01J2002)+2 种基金the Key Research and Development Program of Hainan,China(ZDYF2023XDNY052)the Seed Industry Engineering Project of Department of Agriculture and Rural Affairs of Guangdong,China(2022-NPY-00-004 and 2022-NBH00-001)the Litchi Industry Science and Technology Special Mission of Yunnan,China(202204BI090021)。
文摘Litchi has great economic significance as a global fruit crop.However,the advancement of litchi functional genomics has encountered substantial obstacles due to its recalcitrance to stable transformation.Here,we present an efficacious Agrobacterium tumefaciens-mediated transformation system in somatic embryos of‘Heiye'litchi.This system was developed through the optimization of key variables encompassing explant selection,A.tumefaciens strain delineation,bacterium concentration,infection duration,and infection methodology.The subsequent validation of the transformation technique in litchi was realized through the ectopic expression of LcMYB1,resulting in the generation of transgenic calli.However,the differentiation of transgenic calli into somatic embryos encountered substantial challenges.To delineate the intricate molecular underpinnings of LcMYB1's inhibitory role in somatic embryo induction,a comprehensive transcriptome analysis was conducted that encompassed embryogenic calli(C),globular embryos(G),and transgenic calli(TC).A total of 1,166 common differentially expressed genes(DEGs)were identified between C-vs.-G and C-vs.-TC.Gene Ontology(GO)annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis revealed that these common DEGs were mostly related to plant hormone signal transduction pathways.Furthermore,RT-qPCR corroborated the pronounced down-regulation of numerous genes that are associated with somatic embryo induction within the transgenic calli.The development of this transformation system provides valuable support for functional genomics research in litchi.
基金funded by the Key-Area of Research and Development Program of Guangdong Province,China(2018B020202011)the National Natural Science Foundation of China(31701885)+2 种基金the China Agriculture Research System of MOF and MARA(CARS-32-05)the State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources,China(SKLCUSA-b201716)the YangFan Innovative&Entrepreneurial Research Team Project,China(2014YT02H013)。
文摘Litchi chinensis Sonn is widely cultivated in subtropical regions and has an important economic value.A high-density genetic map is a valuable tool for mapping quantitative trait loci(QTL)and marker-assisted breeding programs.In this study,a single nucleotide polymorphism(SNP)-based high-density linkage map was constructed by a genotyping-by-sequencing(GBS)protocol using an F1 population of 178 progenies between two commercial litchi cultivars,‘Ziniangxi’(dwarf)and‘Feizixiao’(vigorous).The genetic map consisted of 3027 SNP markers with a total length of 1711.97 cM in 15 linkage groups(LGs)and an average marker distance of 0.57 cM.Based on this high-density linkage map and three years of phenotyping,a total of 37 QTLs were detected for eight dwarf-related traits,including length of new branch(LNB),diameter of new branch(DNB),length of common petiole(LCP),diameter of common petiole(DCP),length of internode(LI),length of single leaf(LSL),width of single leaf(WSL),and plant height(PH).These QTLs could explain 8.0 to 14.7%(mean=9.7%)of the phenotypic variation.Among them,several QTL clusters were observed,particularly on LG04 and LG11,which might show enrichment for genes regulating the dwarf-related traits in litchi.There were 126 candidate genes identified within the QTL regions,55 of which are differentially expressed genes by RNA-seq analysis between‘Ziniangxi’and‘Feizixiao’.These DEGs were found to participate in the regulation of cell development,material transportation,signal transduction,and plant morphogenesis,so they might play important roles in regulating plant dwarf-related traits.The high-density genetic map and QTLs identification related to dwarf traits can provide a valuable genetic resource and a basis for marker-assisted selection and genomic studies of litchi.
基金National Natural Science Foundation of China(No.81374025)the Education Department of Jilin Province“13th Five-Year”science and technology research project.
文摘Objective:To investigate the effect of saponin from the seed of Litchi chinensis Sonn(SLS)on the growth and apoptosis of human kidney epithelial cells(HKC)cultured in high glucose.Methods:HKC were cultured in DMEM/F12 medium supplemented with 30 mmol/L glucose and treated with or without SLS.In the normal group,isometric DMEM/F12 medium with 5.5mmol/L glucose was added.The secretion of TGF-β1 and fibronectin(FN)were detected by ELISA.Cell apoptosis was detected by the method of Annexin V-FITC/PI double staining.Western blot was used to detect the level of suppressor of cytokine signaling-1(SOCS-1).Results:The result of ELISA showed that the secretion of TGF-β1 and FN was decreased in SLS groups compared with those in 30 mmol/L glucose treated group(P<0.05).There were more cells apoptosis in 30 mmol/L glucose treated group than that in the normal group(P<0.01).Compared with the 30 mmol/L glucose treated group,the apoptosis of HKC were significantly decreased in SLS groups(P<0.01).Western blot showed that the level of SOCS-1 in high glucose+SLS group was decreased(P<0.01),compared with the high glucose group.Conclusion:SLS can reduce the secretion of TGF-β1 and FN in HKC by reducing the deposition of extracellular matrix.SLS also significantly reduced the apoptosis of HKC by inhibiting the level of SOCS-1.These results suggest the roles of SLS in preventing the progress of glomerular sclerosis.
文摘Polyamines play an important role in plant response to abiotic stress. S-adenosyl-1-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on the shelf life improvement of litchi fruit, SAMDC cDNA isolated from Datura stramonium cloned in pBI121 was introduced into litchi genome by means of Agrobacterium tumefaciens through zygote disc transformation. Transgene and its expression are confirmed by Southern and Northern blot analyses, respectively. Transgenic plants expressing Datura SAMDC produced 1.7- to 2.4-fold higher levels of spermidine and spermine than wildtype plants under normal environmental condition, which indicated that the transgenic litchi presented an enhanced polyamines synthesis compared to wildtype plants. Our results demonstrated clearly that increasing polyamine biosynthesis in plants may be a means of creating improved fruit shelf life germplasm.
文摘Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-Exp1 and Lc-Exp2 , were cloned. Lc-Exp1 and Lc-Exp2 was respectively composed of 531 bp encoding 177 amino acids and 537 bp encoding 179 amino acids. Eight cysteine residues and three tryp-tophan residues, which is supposed to be the characteristics of expansins, are conserved in both Lc-Exp1 and c-Exp2. In addition, the homology between the two expansins is 71. 6% at nucleotide acid sequences and 76.3% at amino acid sequences. The homology of Lc-Exp1 with Fa-Exp2 or Pp-Exp1 was 92.7% or 92.1%, but that of Lc-Exp2 with Fa-Exp2 or Pp-Exp1 was only 77. 4% or 76.3% at amino acid sequences.
基金the Key-Area of Research and Development Program of Guangdong Province(Grant No.2018B020202011)the China Litchi and Longan Industry Technology Research System(Grant No.CARS-32-05)Yang Fan Innovative&Entrepreneurial Research Team Project(Grant No.2014YT02H013)。
文摘Sucrose synthase(SUS,EC 2.4.1.13)is widely considered as a key enzyme involved in plant sucrose metabolism,and the gene family encoding different SUS isozymes has been identified and characterized in several plant species.However,to date scant information about the SUS genes is available in Litchi chinensis Sonn.Here,we identified five SUS genes in litchi.These Lc SUSs shared high levels of similarity in both nucleotide and amino acid sequences.Their gene structure,phylogenetic relationships,and expression profiles were characterized.Gene structure analysis indicated that the Lc SUSs have similar exon-intron structures.Phylogenetic analysis revealed that the five members could be classified into three groups(LcSUS1 and LcSUS2 in SUSⅡ,LcSUS4 and LcSUS5 in SUSⅢ,and LcSUS3 in SUSⅠ),demonstrating evolutionary conservation in the SUS family across litchi and other plant species.The expression levels of Lc SUSs were investigated via real-time PCR in various tissues and different developmental stages of aril.For tissues and organs,Lc SUSs exhibited distinct but partially redundant expression profiles in litchi,being predominantly expressed in young leaves(sink).During aril development,the expression pattern of LcSUS1 was consistent with the trend of sugar accumulation,indicating it may play important roles in determination of sink strength in aril.Moreover,transcript levels of LcSUS2,LcSUS4,and LcSUS5 varied between cultivars with different hexose/sucrose ratios,which may regulate the sugar composition in aril.Our results provide insights into physiological functions of SUS genes in litchi,especially roles in regulating sugar accumulation in aril.
文摘Objective: To synthesize and isolate silver and gold nanoparticles from Litchi chinensis leaf methanolic extract, and to evaluate its comparative biological activities including muscles relaxant, analgesic, anti-inflammatory and antidiarrheal. Methods: The gold and silver nanoparticles were synthesized by dissolving methanolic extract in gold chloride and silver nitrate solution separately which were confirmed by colour change and UV-Vis spectroscopy, and pellets were collected through centrifugation. Biological activities of the extract were conducted on BALB/c mice through various standard methods and the data were subjected to One-way ANOVA. Results: The colorless gold chloride solution changed to purple soon after the addition of plant extract, demonstrating that the reaction took place and gold ions were reduced to gold nanoparticles, while colorless silver nitrate solution changed to light and dark brown that was indicative of silver nanoparticles. The muscles relaxant activity showed that silver nanoparticles were more effective than gold nanoparticles and methanolic extract in traction test. The analgesic activity showed that silver and gold nanoparticles showed highest percentage decrease in acetic acid induced writhing at the doses of 50, 100 and 150 mg/kg b.w. The highest anti-inflammatory activity was produced by gold nanoparticles followed by silver nanoparticles, while low activity was observed in methanolic leaf extract. Only the crude methanolic extract showed significant antidiarrheal activity as compared to the standard drug atropine sulphate, while antidiarrheal activities of gold and silver nanoparticles were non-significant. Conclusions: The present work concludes that isolated silver and gold nanoparticles from leaf methanolic extract shows strong muscles relaxant, analgesic and anti-inflammatory activities while crude methanolic extract possesses good antidiarrheal activity.
文摘Being sensitive to climatic conditions,the growth of Litchi chinensis（ lychee） can be greatly affected both in rainy warm winter which is conductive to winter shoot elongation,seriously affecting the formation of flower buds,and in rainy spring or cold late spring when lychee is flowering,seriously affecting pollination and fruit set. Thus,meteorological conditions play a decisive role in determining the distribution,growth and development,yield formation and quality of lychee. Based on meteorological conditions,some measures can be taken to reduce the impacts of adverse weather and take advantage of favorable weather conditions for the stable and high production of lychee. Therefore,the yield of lychee could be increased by improving the accuracy of weather forecasts and long-term cultivation and management techniques.
基金Supported by National Science Foundation of China ( GrantNo.30460085, 30960233)Open Foundation of Provincial Key Laboratory for Fruit and Vegetable Preservation of Hainan ( GrantNo. CH001)National Non-profit Institute Grant (ITBBZD2007-3-1)~~
文摘[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.
基金supported by grants from the National Key R&D Program of China(Grant No.2019YFD1000900)the Hainan Province Science and Technology Special Fund(Grant No.ZDYF2022XDNY253)the earmarked fund for CARS(Grant No.CARS-32-01)。
文摘Litchi(Litchi chinensis Sonn.)is a type of commercially prevalent subtropical and tropical fruit.Since litchi has a highly heterozygous genetic background and a long reproductive cycle,conventional breeding methods(such as hybridization)have limited ability to nurture new litchi cultivars.Here,an efficient and stable Agrobacterium tumefaciens-mediated genetic transformation of embryogenic callus was established in‘Feizixiao’litchi.Transgenic materials were verified using polymerase chain reaction(PCR)analysis,β-glucuronidase(GUS)assay,and green fluorescent protein(GFP)assay.To implement the technology of the Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)/associated protein 9(CRISPR/Cas9)technology in‘Feizixiao’litchi and verify the validity of these transformation systems,the litchi polyphenol oxidase gene(LcPPO,JF926153)was knocked out.Various categories of mutations,covering base insertions,deletions,and substitutions,were found in transgenic materials via sequence analysis.The transformation system achieved high feasibility and efficiency,and the system of CRISPR/Cas9 was successfully employed to edit genes in‘Feizixiao’litchi.This work provides an essential foundation for investigating the functions of genes and accelerating litchi genetic improvement.
文摘The regulatory role of calcium in fertility of pollen and pistil under simulated acid rain was investigated. The germination percentage of pollen treated with acid rain of pH 4.5 was 9.42% lower than that of control, and that of pH 3.5, pH 2.5 and pH 1.5 were 22.47%, 45.49% and 71.62%, respectively. Simultaneously, the injury character of pollen was obviously observed when flowers were treated with acid rain of pH 3.5. The difference in fruit setting rate between the female flower treated with acid rain of pH 4.0 and the control was significant at p 〈 0.05. Ca（NO3 ）5 of 0.2-0.4 mmol/L could promote pollen germination under the stress of acid rain. The beneficial function was reduced when calcium concentration surpassed 0.8 mmol/L. Spraying 2 mmol/L Ca（NO3 ）5 reduced the injury of acid rain to pistil and increased fruit-setting rate significantly. The physiological importance of calcium during pollen germination and pistil development was also discussed.
文摘Fruit and leaf shoot of litchi （Litchi chinensis） infestation by naturally occurring populations of the fruit bprer, Conopomorpha sinensis larvae and C. sinensis parasitization rates were determined in litchi orchards in northern Thailand at high （ca. 1 400 m ASL） and low （ca. 800 m ASL） elevations with different, non-overlapping fruiting seasons. In addition, spray applications of Bacillus thuringiensis var. aizawai, the natural compound spinosad and the chemical pesticide imidacloprid were conducted in the field to test the effects of these agents on C. sinensis fruit infestation rate. Fruit infestation rate and fruit growth, studied in a low elevation orchard, were sigmoidal and showed a highly significant positive correlation （P ≤ 0.01）. Leaf shoot infestation rate in the low elevation orchard decreased in the course of the fruiting season （March until May）, but increased in the high elevation orchard, where no fruits were present within the same period of time. Together, these results indicate that females of C. sinensis clearly prefer fruits over shoots for oviposition. If no fruits are available, which was the case in the high elevation orchard during that time, they are constrained to lay their eggs on shoots. The parasitization rate of C. sinensis larvae in untreated fruits was 54.3%. The parasitoid species were Chelonus chailini （90.8%） and Phanerotoma sp. （9.2%）. In the leaf shoots, C. sinensis was found to be parasitized by Phanerotoma sp. and Apanteles briareus. The applications of the different active agents had no significant effect on C. sinensis fruit infestation compared to the untreated control. Besides the cryptic life of the larvae, this is most probably explained by the fact that C. sinensis has several generations during the fruiting season. Because of the high parasitization rates recorded, an alternative and more effective control measure than the application of pesticides might be the augmentative release of parasitoids.
