Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic aci...Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.展开更多
The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the p...The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia)PY-9’ was identified and used as the material for anatomical analysis.PY-9’ grew to half the tree height of the normal cultivar Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate betweenPY-9’ andZhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar.PY-9’ showed a higher photosynthetic rate thanZhengdu’. Anatomical analysis showed thatPY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues thanZhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity inZhengdu’ than inPY-9’, which could contribute to the more vigorous growth ofZhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.展开更多
Low temperature is among the most restrictive factors to limit the yield and distribution of pear. Pyrus hopeiensis is a valuable wild resource.PCA showed that P. hopeiensis had strong cold resistance. In this study, ...Low temperature is among the most restrictive factors to limit the yield and distribution of pear. Pyrus hopeiensis is a valuable wild resource.PCA showed that P. hopeiensis had strong cold resistance. In this study, the mRNA and metabolome sequencing of P. hopeiensis flower organs exposed to different low temperatures were performed to identify changes of genes and metabolites in response to low-temperature stress. A total of 4 851 differentially expressed genes(DEGs) were identified. Trend analysis showed that these DEGs were significantly enriched in profiles 19, 18, 7, 14, 1, 4 and 11. And the KEGG enrichment analysis showed that the DEGs in profile 18 were significantly enriched in flavone and flavonol biosynthesis. Besides, the expressed trends as well as GO and KEGG functional enrichment analyses of DEGs under cold and freezing stress showed significantly difference. Analyses of flavonoid-related pathways indicated that flavonoid structural genes had undergone significant changes. Correlation analysis showed that b HLH and MYB TFs may affect flavonoid biosynthesis by regulating structural gene expression. And PhMYB308 and PhMYB330 were likely candidate repressors of flavonoid biosynthesis by binding to a specific site in bHLH proteins. In total, 92 differentially accumulated metabolites(DAMs) were identified in P. hopeiensis flowers including 12 flavonoids. WGCNA results showed that coral 1, pink and brown 4 modules were closely associated with flavonoids and 11 MYBs and 15 bHLHs among the three modules may activate or inhibit the expression of 23 structural genes of flavonoid biosynthesis. Taken together, the results of this study provided a theoretical basis for further exploration of the molecular mechanisms of flavonoid biosynthesis and cold resistance of P. hopeiensis flower organs and our findings laid a foundation for further molecular breeding in cold-resistant pear varieties.展开更多
Pears carry a gametophytic self-incompatibility(SI)system.In this system,S-RNase is the SI pistil determinant,and S-locus F-box brothers(SFBBs)are candidate pollen determinants.However,compared with apple,fewer SFBB g...Pears carry a gametophytic self-incompatibility(SI)system.In this system,S-RNase is the SI pistil determinant,and S-locus F-box brothers(SFBBs)are candidate pollen determinants.However,compared with apple,fewer SFBB genes were identified from pear,possibly caused by the lack of economic and effective methods.Here,we used transcriptome sequencing on‘Yali’(Pyrus bretschneideri)to obtain sequence fragments of SFBB genes and then used polymerase chain reaction(PCR)to amplify the whole sequence of SFBB genes.Twenty-seven SFBB genes,including22 full-length and five nonfull-length SFBB genes,were identified in‘Yali’(P.bretschneideri).SFBBs linkage analysis by PCR-enzyme-linked immunoassay(ELISA)showed that 12 SFBB genes belong to the S21 locus,and 15 SFBB genes belong to the S34 locus.Phylogenetic analysis showed that SFBB genes from Pyrus were divided into 26 types,more than the original eight types.The intrahaplotypic divergence of SFBBs is high and comparable to the allelic diversity of S-RNase,which is consistent with a nonself-recognition SI system.In addition,the expression level of PbrSFBBs in‘Jinzhui’,the only known haploid pollen of a self-compatible mutant,was mostly approximately two times higher than in‘Yali’,which may be the reason for the self-compatible mutant.展开更多
As there is a strong interest in red-skinned pears,the molecular mechanism of anthocyanin regulation in red-skinned pears has been widely investigated;however,little is known about the molecular mechanism of anthocyan...As there is a strong interest in red-skinned pears,the molecular mechanism of anthocyanin regulation in red-skinned pears has been widely investigated;however,little is known about the molecular mechanism of anthocyanin regulation in red-fleshed pears due to limited availability of such germplasm,primarily found in European pears(Pyrus communis).In this study,based on transcriptomic analysis in red-fleshed and white-fleshed pears,we identified an ethylene response factor(ERF)from P.communis,PcERF5,of which expression level in fruit flesh was significantly correlated with anthocyanin content.We then verified the function of PcERF5 in regulating anthocyanin accumulation by genetic transformation in both pear skin and apple calli.PcERF5 regulated anthocyanin biosynthesis by different regulatory pathways.On the one hand,PcERF5 can activate the transcription of flavonoid biosynthetic genes(PcDFR,PcANS and PcUFGT)and two key transcription factors encoding genes PcMYB10 and PcMYB114.On the other hand,PcERF5 interacted with PcMYB10 to form the ERF5-MYB10 protein complex that enhanced the transcriptional activation of PcERF5 on its target genes.Our results suggested that PcERF5 functioned as a transcriptional activator in regulating anthocyanin biosynthesis,which provides new insights into the regulatory mechanism of anthocyanin biosynthesis.This new knowledge will provide guidance for molecular breeding of red-fleshed pear.展开更多
The identification of self-incompatibility genotype (S-genotype) will be useful for selection of pollinizers and design of crossing in cultivar improvement of sand pear. This paper reported the identification of sel...The identification of self-incompatibility genotype (S-genotype) will be useful for selection of pollinizers and design of crossing in cultivar improvement of sand pear. This paper reported the identification of self-incompatibility genotypes of seven Chinese and two Japanese sand pear cultivars using PCR-RFLP analysis and S-RNase sequencing. The Sgenotypes of these cultivars were determined as follows: Huali 1 S1S3, Shounan S1S3, Xizilti S1S4, Qingxiang S3S7, Sanhua S2S7, Huangmi (Imamuranatsu) S1S6, Huali 2 S3S4, Baozhuli S7S33, Cangxixueli S5S15. S-RNase alleles (S1 to S9) in sand pear could be identified effectively by PCR-RFLP analysis.展开更多
The aim of this article is to study the relationship between biosynthesis of anthocyanin and activities of phenylalanine ammonia lyase (PAL), chalcone ismoerase (CHI) enzymes in Pyrus pyrifolia. Changes in the lev...The aim of this article is to study the relationship between biosynthesis of anthocyanin and activities of phenylalanine ammonia lyase (PAL), chalcone ismoerase (CHI) enzymes in Pyrus pyrifolia. Changes in the level of anthocyanin and the activities of enzymes of anthocyanin biosynthesis including PAL, CHI were studied in the pericarp of Pyrus pyrifolia Aoguan and Mantianhong during the period of pigment formation. Bagging treatment was also carried out to manipulate the synthesis of anthocyanin and the activities of related enzymes during the period of pigment formation. The results demonstrated that the level of anthocyanin of Aoguan was higher than that of Mantianhong. However, the content of anthocyanins has the similar changing trend in Aoguan and Mantianhong, highest anthocyanin concentrations of two varieties appeared in immature fruit and faded toward harvest. Meanwhile, similar changing trends of activities of PAL and CHI were also observed in both varieties. Aoguan has a lower activity of PAL than Mantianhong, whereas activity of CHI in Aoguan was higher than that in Mantianhong. Activity of PAL decreased during the period of pigment formation and was apparently not limiting to color development, whereas CHI activity increased at the same period and was closely related to the synthesis of anthocyanin. The results of bagging treatment showed that bagging treatment inhibited the activity of CHI, as well as the synthesis of anthocyanin, whereas debagging enhanced both the activity of CHI and synthesis of anthocyanin. The activity of CHI in debagging Aoguan pericarp was higher than the untreated Aoguan. However, effect of bagging treatment toward PAL activity was not obvious. Anthocyanin of bagging treated Aoguan decreased toward harvest. The content of anthocyanin of Pyruspyrifolia increased at the beginning of fruit coloration period and decreased toward fruit harvest. Activity of PAL was apparently not limiting to color development, whereas CHI activity was closely related to the synthesis of anthocyanin. Debagging enhanced both the activity of CHI and anthocyanin synthesis. Bagging treatment also proved that degradation of anthocyanin was not induced only by light. Light appeared to have two opposing effects in pears: it is required for anthocyanin synthesis and also for apparently increasing red color loss through increased degradation of anthocyanin.展开更多
Pear is a popular and commercially important fresh fruit, and its texture is related to the presence of sclereid formatted by parenchyma cell with lignification in vascular plants. Previous studies have demonstrated t...Pear is a popular and commercially important fresh fruit, and its texture is related to the presence of sclereid formatted by parenchyma cell with lignification in vascular plants. Previous studies have demonstrated that content of lignin may be regulated by cinnamoyl CoA reductase(CCR) in various plants. However, the function of CCR in pears remains very limited. In the present study, we isolated a cDNA encoding CCR(PpCCR, GenBank accession No. KF999958) and its promoter(proPpCCR) from Whangkeumbae pear to investigate the function of CCR in lignin biosynthesis. PpCCR-GFP expressed in rice mesophyll protoplast demonstrated that PpCCR-GFP was localized in the cytoplasm, indicating that CCR may function in cytoplasm without localization signals. In transgenic plants carrying PpCCR, we observed higher lignin content compared with that in wild type plants, further suggesting that PpCCR can affect the lignin contents through regulating lignin biosynthesis in Arabidopsis thaliana. More studies in other plants are needed to confirm our conclusion.展开更多
The purpose of this study is to find a new gene resource for the researches of molecular breeding of Rosaceae plants disease-resistance. Pyrus ussuriensis Maxim is used as a starting material to clone the full-length ...The purpose of this study is to find a new gene resource for the researches of molecular breeding of Rosaceae plants disease-resistance. Pyrus ussuriensis Maxim is used as a starting material to clone the full-length cDNA of NPR1(nonexpressor of pathogenesis- related genes 1) which is a key regulator in SA (salicylic acid)-mediated systemic acquired resistance (SAR) by homologous cloning and RACE techniques. The length of the cDNA sequence was 1 767 bp, the ORF was 1 761 bp, it coded 586 amino acids, pi=5.58, the relative molecular weight was 65.009 ku, contained 19 kinds of amino acids, and had full BTB/POZ and ANK domains. Compared the homology of NPR1 gene in GenBank database, the homology with Pyrus pyrifolia, Arabidopsis thaliana, Nicotiana tabacum, Lycopersicon esculentum, Oryza sativa, Helianthus annuus were 98%, 62%, 68%, 65%, 57%, 63%. The homology offunctional area were 99%, 78%, 82%, 79%, 74%, 77%. This NPR1 gene was considered as homologic gene of Pyrus ussuriensis Maxim and named PumNPR1.展开更多
Pyrus pashia Buch-Ham, a wild specie was used to investigate the physiological effects of iron deficiency in culture solution. The result showed that Chla, Chlb, total chlorophyll content and photosynthesis rate(Pn) d...Pyrus pashia Buch-Ham, a wild specie was used to investigate the physiological effects of iron deficiency in culture solution. The result showed that Chla, Chlb, total chlorophyll content and photosynthesis rate(Pn) decreased sharply, and the decrease of Pn was prior to that of Chl content under the iron deficiency. The iron deficiency symptoms were visible when the iron concentration in culture medium was less than 25 μmol L-1. Peroxidase(POD) and catalase(CAT) activity in iron-deficient leaves declined significantly, and POD was more sensitive than CAT to Fe deficiency. However, the positive correlation between CAT activity and Chl content was more significant than that between POD activity and Chl content. The content of nutrient elements in Fe-deficient leaves, which changed irregularly, were higher than that in normal leaves. There were a most significant positive correlation between active Fe and Chl content, and between active Fe and Pn respectively. Therefore, active Fe could be useful physiological predicting index for diagnosis.展开更多
China is not only one of the origin centers of Pyrus L.,but also the earliest birthplace of Pyrus L.in the world.This paper reviews the evolution of Pyrus L.from the aspects of leaf edge morphology,inflorescence and f...China is not only one of the origin centers of Pyrus L.,but also the earliest birthplace of Pyrus L.in the world.This paper reviews the evolution of Pyrus L.from the aspects of leaf edge morphology,inflorescence and fruit type,and summarizes the research progress of classification and species distribution of Pyrus L.,which is of great significance for the protection,evaluation and utilization of germplasm resources.展开更多
基金supported by the National Natural Science Foundation of China(32272654)the Natural Science Foundation of Hebei Province China(C2023204016)+2 种基金the Hebei Province Introduced Overseas-Scholar Fund China(C20220361)the S&T Program of Hebei China(20326330D)the Hebei Province Outstanding Youth Fund China(2016,2019)。
文摘Pyrus pyrifolia Nakai‘Whangkeumbae'is a sand pear fruit with excellent nutritional quality and taste.However,the industrial development of pear fruit is significantly limited by its short shelf life.Salicylic acid(SA),a well-known phytohormone,can delay fruit senescence and improve shelf life.However,the mechanism by which SA regulates CONSTANS-LIKE genes(COLs)during fruit senescence and the role of COL genes in mediating fruit senescence in sand pear are poorly understood.In this study,22 COL genes were identified in sand pear,including four COLs(Pp COL8,Pp COL9a,Pp COL9b,and Pp COL14)identified via transcriptome analysis and 18 COLs through genome-wide analysis.These COL genes were divided into three subgroups according to the structural domains of the COL protein.Pp COL8,with two B-box motifs and one CCT domain,belonged to the first subgroup.In contrast,the other three Pp COLs,Pp COL9a,Pp COL9b,and Pp COL14,with similar conserved protein domains and gene structures,were assigned to the third subgroup.The four COLs showed different expression patterns in pear tissues and were preferentially expressed at the early stage of fruit development.Moreover,the expression of Pp COL8 was inhibited by exogenous SA treatment,while SA up-regulated the expression of Pp COL9a and Pp COL9b.Interestingly,Pp COL8 interacts with Pp MADS,a MADS-box protein preferentially expressed in fruit,and SA up-regulated its expression.While the production of ethylene and the content of malondialdehyde(MDA)were increased in Pp COL8-overexpression sand pear fruit,the antioxidant enzyme(POD and SOD)activity and the expression of Pp POD1 and Pp SOD1 in the sand pear fruits were down-regulated,which showed that Pp COL8 promoted sand pear fruit senescence.In contrast,the corresponding changes were the opposite in Pp MADS-overexpression sand pear fruits,suggesting that Pp MADS delayed sand pear fruit senescence.The co-transformation of Pp COL8 and Pp MADS also delayed sand pear fruit senescence.The results of this study revealed that Pp COL8 can play a key role in pear fruit senescence by interacting with Pp MADS through the SA signaling pathway.
基金supported by grants from the Agriculture Science and Technology of Shandong Province (Grant No.2019YQ015)the Agricultural Variety Improvement Project of Shandong Province (Grant No.2022LZGC011)the earmarked fund for CARS (Grant No.CARS-28-07)。
文摘The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia)PY-9’ was identified and used as the material for anatomical analysis.PY-9’ grew to half the tree height of the normal cultivar Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate betweenPY-9’ andZhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar.PY-9’ showed a higher photosynthetic rate thanZhengdu’. Anatomical analysis showed thatPY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues thanZhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity inZhengdu’ than inPY-9’, which could contribute to the more vigorous growth ofZhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.
基金supported by the National Key Research and Development Plan“Research on protection and restoration of typical small populations of wild plants”(Grant No.2016YFC0503106)。
文摘Low temperature is among the most restrictive factors to limit the yield and distribution of pear. Pyrus hopeiensis is a valuable wild resource.PCA showed that P. hopeiensis had strong cold resistance. In this study, the mRNA and metabolome sequencing of P. hopeiensis flower organs exposed to different low temperatures were performed to identify changes of genes and metabolites in response to low-temperature stress. A total of 4 851 differentially expressed genes(DEGs) were identified. Trend analysis showed that these DEGs were significantly enriched in profiles 19, 18, 7, 14, 1, 4 and 11. And the KEGG enrichment analysis showed that the DEGs in profile 18 were significantly enriched in flavone and flavonol biosynthesis. Besides, the expressed trends as well as GO and KEGG functional enrichment analyses of DEGs under cold and freezing stress showed significantly difference. Analyses of flavonoid-related pathways indicated that flavonoid structural genes had undergone significant changes. Correlation analysis showed that b HLH and MYB TFs may affect flavonoid biosynthesis by regulating structural gene expression. And PhMYB308 and PhMYB330 were likely candidate repressors of flavonoid biosynthesis by binding to a specific site in bHLH proteins. In total, 92 differentially accumulated metabolites(DAMs) were identified in P. hopeiensis flowers including 12 flavonoids. WGCNA results showed that coral 1, pink and brown 4 modules were closely associated with flavonoids and 11 MYBs and 15 bHLHs among the three modules may activate or inhibit the expression of 23 structural genes of flavonoid biosynthesis. Taken together, the results of this study provided a theoretical basis for further exploration of the molecular mechanisms of flavonoid biosynthesis and cold resistance of P. hopeiensis flower organs and our findings laid a foundation for further molecular breeding in cold-resistant pear varieties.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFD1000107)National Natural Science Foundation of China(Grant No.32001983)the Natural Science Foundation of Jiangsu Province(Grant No.BK20190896)。
文摘Pears carry a gametophytic self-incompatibility(SI)system.In this system,S-RNase is the SI pistil determinant,and S-locus F-box brothers(SFBBs)are candidate pollen determinants.However,compared with apple,fewer SFBB genes were identified from pear,possibly caused by the lack of economic and effective methods.Here,we used transcriptome sequencing on‘Yali’(Pyrus bretschneideri)to obtain sequence fragments of SFBB genes and then used polymerase chain reaction(PCR)to amplify the whole sequence of SFBB genes.Twenty-seven SFBB genes,including22 full-length and five nonfull-length SFBB genes,were identified in‘Yali’(P.bretschneideri).SFBBs linkage analysis by PCR-enzyme-linked immunoassay(ELISA)showed that 12 SFBB genes belong to the S21 locus,and 15 SFBB genes belong to the S34 locus.Phylogenetic analysis showed that SFBB genes from Pyrus were divided into 26 types,more than the original eight types.The intrahaplotypic divergence of SFBBs is high and comparable to the allelic diversity of S-RNase,which is consistent with a nonself-recognition SI system.In addition,the expression level of PbrSFBBs in‘Jinzhui’,the only known haploid pollen of a self-compatible mutant,was mostly approximately two times higher than in‘Yali’,which may be the reason for the self-compatible mutant.
基金funded by the National Natural Science Foundation of China(31820103012)the earmarked fund for China Agriculture Research System(CARS-28)the earmarked fund for Jiangsu Agricultural Industry Technology System,China(JATS[2022]454).
文摘As there is a strong interest in red-skinned pears,the molecular mechanism of anthocyanin regulation in red-skinned pears has been widely investigated;however,little is known about the molecular mechanism of anthocyanin regulation in red-fleshed pears due to limited availability of such germplasm,primarily found in European pears(Pyrus communis).In this study,based on transcriptomic analysis in red-fleshed and white-fleshed pears,we identified an ethylene response factor(ERF)from P.communis,PcERF5,of which expression level in fruit flesh was significantly correlated with anthocyanin content.We then verified the function of PcERF5 in regulating anthocyanin accumulation by genetic transformation in both pear skin and apple calli.PcERF5 regulated anthocyanin biosynthesis by different regulatory pathways.On the one hand,PcERF5 can activate the transcription of flavonoid biosynthetic genes(PcDFR,PcANS and PcUFGT)and two key transcription factors encoding genes PcMYB10 and PcMYB114.On the other hand,PcERF5 interacted with PcMYB10 to form the ERF5-MYB10 protein complex that enhanced the transcriptional activation of PcERF5 on its target genes.Our results suggested that PcERF5 functioned as a transcriptional activator in regulating anthocyanin biosynthesis,which provides new insights into the regulatory mechanism of anthocyanin biosynthesis.This new knowledge will provide guidance for molecular breeding of red-fleshed pear.
基金supported in part by Natural Science Foundation of JiangxiAgricultural University, China (1878).
文摘The identification of self-incompatibility genotype (S-genotype) will be useful for selection of pollinizers and design of crossing in cultivar improvement of sand pear. This paper reported the identification of self-incompatibility genotypes of seven Chinese and two Japanese sand pear cultivars using PCR-RFLP analysis and S-RNase sequencing. The Sgenotypes of these cultivars were determined as follows: Huali 1 S1S3, Shounan S1S3, Xizilti S1S4, Qingxiang S3S7, Sanhua S2S7, Huangmi (Imamuranatsu) S1S6, Huali 2 S3S4, Baozhuli S7S33, Cangxixueli S5S15. S-RNase alleles (S1 to S9) in sand pear could be identified effectively by PCR-RFLP analysis.
基金supported by the National 863 Program of China (2006AA100108)
文摘The aim of this article is to study the relationship between biosynthesis of anthocyanin and activities of phenylalanine ammonia lyase (PAL), chalcone ismoerase (CHI) enzymes in Pyrus pyrifolia. Changes in the level of anthocyanin and the activities of enzymes of anthocyanin biosynthesis including PAL, CHI were studied in the pericarp of Pyrus pyrifolia Aoguan and Mantianhong during the period of pigment formation. Bagging treatment was also carried out to manipulate the synthesis of anthocyanin and the activities of related enzymes during the period of pigment formation. The results demonstrated that the level of anthocyanin of Aoguan was higher than that of Mantianhong. However, the content of anthocyanins has the similar changing trend in Aoguan and Mantianhong, highest anthocyanin concentrations of two varieties appeared in immature fruit and faded toward harvest. Meanwhile, similar changing trends of activities of PAL and CHI were also observed in both varieties. Aoguan has a lower activity of PAL than Mantianhong, whereas activity of CHI in Aoguan was higher than that in Mantianhong. Activity of PAL decreased during the period of pigment formation and was apparently not limiting to color development, whereas CHI activity increased at the same period and was closely related to the synthesis of anthocyanin. The results of bagging treatment showed that bagging treatment inhibited the activity of CHI, as well as the synthesis of anthocyanin, whereas debagging enhanced both the activity of CHI and synthesis of anthocyanin. The activity of CHI in debagging Aoguan pericarp was higher than the untreated Aoguan. However, effect of bagging treatment toward PAL activity was not obvious. Anthocyanin of bagging treated Aoguan decreased toward harvest. The content of anthocyanin of Pyruspyrifolia increased at the beginning of fruit coloration period and decreased toward fruit harvest. Activity of PAL was apparently not limiting to color development, whereas CHI activity was closely related to the synthesis of anthocyanin. Debagging enhanced both the activity of CHI and anthocyanin synthesis. Bagging treatment also proved that degradation of anthocyanin was not induced only by light. Light appeared to have two opposing effects in pears: it is required for anthocyanin synthesis and also for apparently increasing red color loss through increased degradation of anthocyanin.
基金Supported by the Earmarked Fund for China Agriculture Research System(CARS-2917)Hubei Innovation Center of Agricultural Science and Technology(2011-620-005003)
文摘Pear is a popular and commercially important fresh fruit, and its texture is related to the presence of sclereid formatted by parenchyma cell with lignification in vascular plants. Previous studies have demonstrated that content of lignin may be regulated by cinnamoyl CoA reductase(CCR) in various plants. However, the function of CCR in pears remains very limited. In the present study, we isolated a cDNA encoding CCR(PpCCR, GenBank accession No. KF999958) and its promoter(proPpCCR) from Whangkeumbae pear to investigate the function of CCR in lignin biosynthesis. PpCCR-GFP expressed in rice mesophyll protoplast demonstrated that PpCCR-GFP was localized in the cytoplasm, indicating that CCR may function in cytoplasm without localization signals. In transgenic plants carrying PpCCR, we observed higher lignin content compared with that in wild type plants, further suggesting that PpCCR can affect the lignin contents through regulating lignin biosynthesis in Arabidopsis thaliana. More studies in other plants are needed to confirm our conclusion.
文摘The purpose of this study is to find a new gene resource for the researches of molecular breeding of Rosaceae plants disease-resistance. Pyrus ussuriensis Maxim is used as a starting material to clone the full-length cDNA of NPR1(nonexpressor of pathogenesis- related genes 1) which is a key regulator in SA (salicylic acid)-mediated systemic acquired resistance (SAR) by homologous cloning and RACE techniques. The length of the cDNA sequence was 1 767 bp, the ORF was 1 761 bp, it coded 586 amino acids, pi=5.58, the relative molecular weight was 65.009 ku, contained 19 kinds of amino acids, and had full BTB/POZ and ANK domains. Compared the homology of NPR1 gene in GenBank database, the homology with Pyrus pyrifolia, Arabidopsis thaliana, Nicotiana tabacum, Lycopersicon esculentum, Oryza sativa, Helianthus annuus were 98%, 62%, 68%, 65%, 57%, 63%. The homology offunctional area were 99%, 78%, 82%, 79%, 74%, 77%. This NPR1 gene was considered as homologic gene of Pyrus ussuriensis Maxim and named PumNPR1.
文摘Pyrus pashia Buch-Ham, a wild specie was used to investigate the physiological effects of iron deficiency in culture solution. The result showed that Chla, Chlb, total chlorophyll content and photosynthesis rate(Pn) decreased sharply, and the decrease of Pn was prior to that of Chl content under the iron deficiency. The iron deficiency symptoms were visible when the iron concentration in culture medium was less than 25 μmol L-1. Peroxidase(POD) and catalase(CAT) activity in iron-deficient leaves declined significantly, and POD was more sensitive than CAT to Fe deficiency. However, the positive correlation between CAT activity and Chl content was more significant than that between POD activity and Chl content. The content of nutrient elements in Fe-deficient leaves, which changed irregularly, were higher than that in normal leaves. There were a most significant positive correlation between active Fe and Chl content, and between active Fe and Pn respectively. Therefore, active Fe could be useful physiological predicting index for diagnosis.
基金Supported by the Natural Science Foundation of Henan Provincial Department of Science and Technology(222300420508)Henan Provincial Key Science and Technology Research Project(202102310478)+1 种基金the Ph D Research Fund of Pingdingshan University(PXY-BSQD-2012009)Training Program for Young Backbone Teachers in Higher Education Institutions in Henan Province(2021GGJS147)。
文摘China is not only one of the origin centers of Pyrus L.,but also the earliest birthplace of Pyrus L.in the world.This paper reviews the evolution of Pyrus L.from the aspects of leaf edge morphology,inflorescence and fruit type,and summarizes the research progress of classification and species distribution of Pyrus L.,which is of great significance for the protection,evaluation and utilization of germplasm resources.