Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, ...Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance （TBARS） and antioxidant enzymes activities were investigated during leaf senescence of PSA612-1PT modified gerbera induced by osmotic stress compared with the control plant （wild type）. Leaf discs were incubated in 20%, 40% （w/v） polyethylene glycol （PEG） 6 000 nutrient solution for 20 h under continuous light [ 130 μmol/（m^2·s）]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase （SOD）, catalases （CAT）, ascorbate peroxidase （APX）, guaiacol peroxidase （GPX） and dehydroascorbate reductase （DHAR） were stimulated by PEG treatment. However, the increases were higher in PSA612-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation （TBARS content） was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant. It could be concluded that the increases in the activities ofantioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress.展开更多
This study was conducted to determine effects of 2,4-dichlorophenoxy acetic acid(2,4-D) and light on growth of gerbera(Gerbera jamesonii cv. Daxueju) callus. Callus was induced from both petiole and leaf explants of g...This study was conducted to determine effects of 2,4-dichlorophenoxy acetic acid(2,4-D) and light on growth of gerbera(Gerbera jamesonii cv. Daxueju) callus. Callus was induced from both petiole and leaf explants of gerbera on Murashige and Skoog medium supplemented with 3% sucrose and various concentrations of 2,4-D and placed under light and dark. Callus induction percentage, callus size and callus fresh and dry weights were efficiently higher when using petiole as explant. MS medium supplemented with 1.5 mg/L 2,4-D showed the highest callus induction percentage of 96.70%. Callus induced under light had larger weight mass. It was indicated that 1.5 mg/L 2,4-D and light could promote growth of gerbera callus from petiole explant.展开更多
In this paper, using in vitro leaf disc culture system, the changes of contents of chlorophylls, carotenoids, soluble protein, thiobarbituric acid reactive substance （TBARS）, and activities of antioxidant enzymes we...In this paper, using in vitro leaf disc culture system, the changes of contents of chlorophylls, carotenoids, soluble protein, thiobarbituric acid reactive substance （TBARS）, and activities of antioxidant enzymes were investigated during the incubation of leaf discs of PSAG12-IPT modified gerbera in 0, 25, 50 μmol L^-1 paraquat （PQ） under continuous light intensity of 130 0tool m-2 s-1, compared with the control plant （wild type）. The results showed that PQ treatment significantly decreased the contents of chlorophylls, carotenoids, and soluble protein, therefore, promoted leaf senescence. However, the decreases in the leaf discs of modified gerbera were considerably smaller. The activities of superoxide dismutase （SOD）, catalase （CAT）, and dehydroascorbate reductase （DHAR） were significantly increased by PQ treatment and with the increasing of PQ concentration, particularly in the modified plants. The activities of ascorbate peroxidase （APX） and guaiacol peroxidase （GPX） could not be detected in the leaf discs of PQ treatments, which suggested that they were labile to the oxidative stress induced by PQ. As a product of lipid peroxidation, TBARS significantly increased in content with the increase of PQ concentration, while its concentration in the modified plants was significantly lower than that of control plants. Therefore, it could be concluded that the chimeric gene PSAG12-IPTtransfonnexi gerbera leaves had higher antioxidative potential, thus causing the delay of senescence under oxidative stress induced by PQ.展开更多
Meiotic recombination and the resulting novel allele combinations are fundamental to plant breeding and the identification of superior hybrids.However,the rate of meiotic crossovers is naturally suppressed below its p...Meiotic recombination and the resulting novel allele combinations are fundamental to plant breeding and the identification of superior hybrids.However,the rate of meiotic crossovers is naturally suppressed below its potential ability,which prevents plant breeding efficiency.Nine suppressors of meiotic recombination have been identified in the model plant Arabidopsis and in other crop species.Mutations in these genes can lead to increased recombination frequency and could therefore potentially be used to create hyper-recombinant lines for ornamental breeding.In Gerbera hybrida,the anti-crossover factors remain elusive.In this study,we isolated and cloned TOP3αfrom flower buds of G.hybrida,and it encoded 935 amino acids with three conserved domains TOPRIM,TOP1Ac and zf-GR.Moreover,TOP3αwas the highest expressed at the flower bud stage,which coincided with the occurrence of meiotic recombination,suggesting that TOP3αis associated with the regulation of meiotic recombination in G.hybrida.展开更多
In our previous study,a gene predicted to encode a Tyrosine aminotransferase( TAT) was found to be significantly up-regulated in root rot diseased Gerbera by transcriptome sequencing. To confirm the genes and investig...In our previous study,a gene predicted to encode a Tyrosine aminotransferase( TAT) was found to be significantly up-regulated in root rot diseased Gerbera by transcriptome sequencing. To confirm the genes and investigate the function,we cloned the gene by RT-PCR and then conduct bioinformatic analyses. In this study,a 1 537 bp long c DNA sequence of this gene( named as Gh TAT) was firstly cloned,which contained a coding region of 1 233 bp,which was predicted to encode a protein of 410 amino acids. Bioinformatic analysis showed that the Gh TAT was a stable hydrophobic protein without signal peptide. Subcellular location prediction result indicated that this protein located in chloroplast,which is the biosynthesis position of tyrosine and the derived products of tyrosine biosynthesis pathway. Moreover,typical Tyrosine aminotransferase domain was found in this protein,indicating that it is a TAT. According to the TAT-based phylogenetic analysis and similarity analysis,the closest relationship and highest similarity was found between Gh TAT and Halianthus annuus TAT,which again verified the TAT property of Gh TAT. Tyrosine aminotransferase( TAT) is the first enzyme in tyrosine biosynthesis pathway,whose products include many antioxidant substances such as tocopherols and tocotrienols. The up-regulation of Gh TAT in root rot diseased gerbera suggests that it may play an important role in response to the root rot pathogen infection. In addition,60 phosphorylation sites( accounting for 14. 6%) were found in this protein,suggesting that the expression of this protein and its encoding gene were greatly influenced by the phosphorylation reactions.展开更多
A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene...A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene scaffold.Their planar and three-dimensional structures were exhaustively characterized by comprehensive spectroscopic data and X-ray diffraction analysis.Guided by the hypothetical biosynthetic pathway,the biomimetic synthesis of racemic 1 was achieved using 4-hydroxy-5-methylcoumarin and citral as the starting material via oxa-6πelectrocyclization and intramolecular[2+2]photocycloaddition.Subsequently,the results of the biological activity assay demonstrated that both(+)-1a and(-)-1b exhibited potent lipid-lowering effects in 3T3-L1 adipocytes and the high-fat diet zebrafish model.Notably,the lipid-lowering activity of(+)-1a is better than that of(-)-1b at the same concentration,and molecular mechanism study has shown that(+)-1a and(-)-1b impairs adipocyte differentiation and stimulate lipolysis by regulating C/EBPα/PPARγsignaling and Perilipin signaling in vitro and in vivo.Our findings provide a promising drug model molecule for the treatment of obesity.展开更多
PRPs (proline-rich proteins) are a group of cell wall proteins characterized by their proline and hy- droproline-rich repetitive peptides. The expression of PRPs in plants is stimulated by wounding and environmental s...PRPs (proline-rich proteins) are a group of cell wall proteins characterized by their proline and hy- droproline-rich repetitive peptides. The expression of PRPs in plants is stimulated by wounding and environmental stress. GASA (gibberellic acid stimulated in Arabidopsis) proteins are small peptides sharing a 60 amino acid conserved C-terminal domain containing twelve invariant cysteine residues. Most of GASAs reported are localized to apoplasm or cell wall and their expression was regulated by gibberellins (GAs). It has been reported that, in French bean, these two proteins encoding by two distinct genes formed a two-component chitin-receptor involved in plant-pathogen interactions when plant was infected. We cloned a full-length cDNA of PRGL (proline-rich GASA-like) gene which encodes a protein containing both PRP and GASA-like domains. It is demonstrated that PRGL is a new protein with characteristics of PRP and GASA by analyzing its protein structure and gene expression.展开更多
The molecular mechanism regulating petal length in flowers is not well understood.Here we used transient transformation assays to confirm that GhPRGL(proline-rich and GASA-like)—a GASA(gibberellic acid[GA]stimulated ...The molecular mechanism regulating petal length in flowers is not well understood.Here we used transient transformation assays to confirm that GhPRGL(proline-rich and GASA-like)—a GASA(gibberellic acid[GA]stimulated in Arabidopsis)family gene—promotes the elongation of ray petals in gerbera(Gerbera hybrida).Yeast one-hybrid screening assay identified a bHLH transcription factor of the jasmonic acid(JA)signaling pathway,here named GhBPE(BIGPETAL),which binds to the GhPRGL promoter and represses its expression,resulting in a phenotype of shortened ray petal length when GhBPE is overexpressed.Further,the joint response to JA and GA of GhBPE and GhPRGL,together with their complementary expression profiles in the early stage of petal growth,suggests a novel GhBPE-GhPRGL module that controls the size of ray petals.GhPRGL promotes ray petal elongation in its early stage especially,while GhBPE inhibits ray petal elongation particularly in the late stage by inhibiting the expression of GhPRGL.JA and GA operate in concert to regulate the expression of GhBPE and GhPRGL genes,providing a regulatory mechanism by which ray petals could grow to a fixed length in gerbera species.展开更多
文摘Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance （TBARS） and antioxidant enzymes activities were investigated during leaf senescence of PSA612-1PT modified gerbera induced by osmotic stress compared with the control plant （wild type）. Leaf discs were incubated in 20%, 40% （w/v） polyethylene glycol （PEG） 6 000 nutrient solution for 20 h under continuous light [ 130 μmol/（m^2·s）]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase （SOD）, catalases （CAT）, ascorbate peroxidase （APX）, guaiacol peroxidase （GPX） and dehydroascorbate reductase （DHAR） were stimulated by PEG treatment. However, the increases were higher in PSA612-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation （TBARS content） was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant. It could be concluded that the increases in the activities ofantioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress.
基金Supported by Major Science and Technology Project of Fujian Province(2015NZ0002-1)
文摘This study was conducted to determine effects of 2,4-dichlorophenoxy acetic acid(2,4-D) and light on growth of gerbera(Gerbera jamesonii cv. Daxueju) callus. Callus was induced from both petiole and leaf explants of gerbera on Murashige and Skoog medium supplemented with 3% sucrose and various concentrations of 2,4-D and placed under light and dark. Callus induction percentage, callus size and callus fresh and dry weights were efficiently higher when using petiole as explant. MS medium supplemented with 1.5 mg/L 2,4-D showed the highest callus induction percentage of 96.70%. Callus induced under light had larger weight mass. It was indicated that 1.5 mg/L 2,4-D and light could promote growth of gerbera callus from petiole explant.
文摘In this paper, using in vitro leaf disc culture system, the changes of contents of chlorophylls, carotenoids, soluble protein, thiobarbituric acid reactive substance （TBARS）, and activities of antioxidant enzymes were investigated during the incubation of leaf discs of PSAG12-IPT modified gerbera in 0, 25, 50 μmol L^-1 paraquat （PQ） under continuous light intensity of 130 0tool m-2 s-1, compared with the control plant （wild type）. The results showed that PQ treatment significantly decreased the contents of chlorophylls, carotenoids, and soluble protein, therefore, promoted leaf senescence. However, the decreases in the leaf discs of modified gerbera were considerably smaller. The activities of superoxide dismutase （SOD）, catalase （CAT）, and dehydroascorbate reductase （DHAR） were significantly increased by PQ treatment and with the increasing of PQ concentration, particularly in the modified plants. The activities of ascorbate peroxidase （APX） and guaiacol peroxidase （GPX） could not be detected in the leaf discs of PQ treatments, which suggested that they were labile to the oxidative stress induced by PQ. As a product of lipid peroxidation, TBARS significantly increased in content with the increase of PQ concentration, while its concentration in the modified plants was significantly lower than that of control plants. Therefore, it could be concluded that the chimeric gene PSAG12-IPTtransfonnexi gerbera leaves had higher antioxidative potential, thus causing the delay of senescence under oxidative stress induced by PQ.
基金the Basic Research Program of Yunnan Province-Youth Project(Grant No.2019FD030)the National Natural Science Foundation of China(Grant No.31960608)the Ten-thousand Talents Program of Yunnan Province–Yunling Scholar of Industrial Technology Leading Talent Project(Grant No.Yun Fagai Renshi[2018]No.212).
文摘Meiotic recombination and the resulting novel allele combinations are fundamental to plant breeding and the identification of superior hybrids.However,the rate of meiotic crossovers is naturally suppressed below its potential ability,which prevents plant breeding efficiency.Nine suppressors of meiotic recombination have been identified in the model plant Arabidopsis and in other crop species.Mutations in these genes can lead to increased recombination frequency and could therefore potentially be used to create hyper-recombinant lines for ornamental breeding.In Gerbera hybrida,the anti-crossover factors remain elusive.In this study,we isolated and cloned TOP3αfrom flower buds of G.hybrida,and it encoded 935 amino acids with three conserved domains TOPRIM,TOP1Ac and zf-GR.Moreover,TOP3αwas the highest expressed at the flower bud stage,which coincided with the occurrence of meiotic recombination,suggesting that TOP3αis associated with the regulation of meiotic recombination in G.hybrida.
基金Supported by Science and Technology Plan Major Projects of Fujian Province(2015NZ0002-1)
文摘In our previous study,a gene predicted to encode a Tyrosine aminotransferase( TAT) was found to be significantly up-regulated in root rot diseased Gerbera by transcriptome sequencing. To confirm the genes and investigate the function,we cloned the gene by RT-PCR and then conduct bioinformatic analyses. In this study,a 1 537 bp long c DNA sequence of this gene( named as Gh TAT) was firstly cloned,which contained a coding region of 1 233 bp,which was predicted to encode a protein of 410 amino acids. Bioinformatic analysis showed that the Gh TAT was a stable hydrophobic protein without signal peptide. Subcellular location prediction result indicated that this protein located in chloroplast,which is the biosynthesis position of tyrosine and the derived products of tyrosine biosynthesis pathway. Moreover,typical Tyrosine aminotransferase domain was found in this protein,indicating that it is a TAT. According to the TAT-based phylogenetic analysis and similarity analysis,the closest relationship and highest similarity was found between Gh TAT and Halianthus annuus TAT,which again verified the TAT property of Gh TAT. Tyrosine aminotransferase( TAT) is the first enzyme in tyrosine biosynthesis pathway,whose products include many antioxidant substances such as tocopherols and tocotrienols. The up-regulation of Gh TAT in root rot diseased gerbera suggests that it may play an important role in response to the root rot pathogen infection. In addition,60 phosphorylation sites( accounting for 14. 6%) were found in this protein,suggesting that the expression of this protein and its encoding gene were greatly influenced by the phosphorylation reactions.
基金support from the Natural Sciences Foundation of China(82374035)the CAMS Innovation Fund for Medical Sciences(CIFMS,2022-I2M-1-017,China).
文摘A pair of coumarin-based polycyclic meroterpenoid enantiomers(+)/(-)-gerbeloid A[(+)-1a and(-)-1b]were isolated from the medicinal plant Gerbera piloselloides,which have a unique caged oxatricyclo[4.2.2.0^(3,8)]decene scaffold.Their planar and three-dimensional structures were exhaustively characterized by comprehensive spectroscopic data and X-ray diffraction analysis.Guided by the hypothetical biosynthetic pathway,the biomimetic synthesis of racemic 1 was achieved using 4-hydroxy-5-methylcoumarin and citral as the starting material via oxa-6πelectrocyclization and intramolecular[2+2]photocycloaddition.Subsequently,the results of the biological activity assay demonstrated that both(+)-1a and(-)-1b exhibited potent lipid-lowering effects in 3T3-L1 adipocytes and the high-fat diet zebrafish model.Notably,the lipid-lowering activity of(+)-1a is better than that of(-)-1b at the same concentration,and molecular mechanism study has shown that(+)-1a and(-)-1b impairs adipocyte differentiation and stimulate lipolysis by regulating C/EBPα/PPARγsignaling and Perilipin signaling in vitro and in vivo.Our findings provide a promising drug model molecule for the treatment of obesity.
基金the National Natural Science Foundation of China (Grant No. 30570165)Natural Science Foundation of Guangdong Province of China (Grant Nos. 5005912 and 2006A20101007)
文摘PRPs (proline-rich proteins) are a group of cell wall proteins characterized by their proline and hy- droproline-rich repetitive peptides. The expression of PRPs in plants is stimulated by wounding and environmental stress. GASA (gibberellic acid stimulated in Arabidopsis) proteins are small peptides sharing a 60 amino acid conserved C-terminal domain containing twelve invariant cysteine residues. Most of GASAs reported are localized to apoplasm or cell wall and their expression was regulated by gibberellins (GAs). It has been reported that, in French bean, these two proteins encoding by two distinct genes formed a two-component chitin-receptor involved in plant-pathogen interactions when plant was infected. We cloned a full-length cDNA of PRGL (proline-rich GASA-like) gene which encodes a protein containing both PRP and GASA-like domains. It is demonstrated that PRGL is a new protein with characteristics of PRP and GASA by analyzing its protein structure and gene expression.
基金This work was supported by Laboratory of Lingnan Modern Agriculture Project(NZ2021009)Natural Science Foundation of Guangdong Province(2021A1515012479)+2 种基金National Key R&D Program of China(2018YFD1000404)National Natural Science Foundation of China(31672188)Guangdong Basic and Applied Basic Research Foundation(2021A1515111227).
文摘The molecular mechanism regulating petal length in flowers is not well understood.Here we used transient transformation assays to confirm that GhPRGL(proline-rich and GASA-like)—a GASA(gibberellic acid[GA]stimulated in Arabidopsis)family gene—promotes the elongation of ray petals in gerbera(Gerbera hybrida).Yeast one-hybrid screening assay identified a bHLH transcription factor of the jasmonic acid(JA)signaling pathway,here named GhBPE(BIGPETAL),which binds to the GhPRGL promoter and represses its expression,resulting in a phenotype of shortened ray petal length when GhBPE is overexpressed.Further,the joint response to JA and GA of GhBPE and GhPRGL,together with their complementary expression profiles in the early stage of petal growth,suggests a novel GhBPE-GhPRGL module that controls the size of ray petals.GhPRGL promotes ray petal elongation in its early stage especially,while GhBPE inhibits ray petal elongation particularly in the late stage by inhibiting the expression of GhPRGL.JA and GA operate in concert to regulate the expression of GhBPE and GhPRGL genes,providing a regulatory mechanism by which ray petals could grow to a fixed length in gerbera species.
