As a ubiquitous reaction, glucosylation controls the bioactivity of cytokinins in plant growth and development. Here we show that genetic manipulation of zeatin-O- glucosylation regulates the formation of important ag...As a ubiquitous reaction, glucosylation controls the bioactivity of cytokinins in plant growth and development. Here we show that genetic manipulation of zeatin-O- glucosylation regulates the formation of important agronomic traits in rice by manipulating the expression of OscZOG1 gene, encoding a putative zeatin O-glucosyltransferase. We found that OscZOG~ was preferentially expressed in shoot and root meristematic tissues and nascent organs. The growth of lateral roots was stimulated in the overexpression lines, but inhibited in RNA interference lines. In shoots, knockdown of OscZOG1 expression by RNA interference significantly im- proved tillering, panicle branching, grain number per panicle and seed size, which are important agronomic traits for grain yield. In contrast, constitutive expression of OscZOG1 leads to negative effects on the formation of the grain-yielding traits with a marked increase in the accumulation levels of cis-zeatin O-glucoside （cZOG） in the transgenic rice plants. In this study,our findings demonstrate the feasibility of improving the critical yield-determinant agronomic traits, including tiller number, panicle branches, total grain number per panicle and grain weight by downregulating the expression level of OscZOG1. Our results suggest that modulating the levels of cytokinin glucosylation can function as a fine-tuning switch in regulating the formation of agronomic traits in rice.展开更多
We report here on a comparative developmental profile of plant hormone cytokinins in relation to cell size, cell number and endoreduplicaUon in developing maize caryopsis of a cell wall invertase-deficient miniature1 ...We report here on a comparative developmental profile of plant hormone cytokinins in relation to cell size, cell number and endoreduplicaUon in developing maize caryopsis of a cell wall invertase-deficient miniature1 （mn1） seed mutant and its wild type, Mn1, genotype. Both genotypes showed extremely high levels of total cytokinins during the very early stages of development, followed by a marked and genotype specific reduction. While the decrease of cytokinins in Mn1 was associated with their deactivation by 9-glucosylation, the absolute and the relative part of active cytokinin forms was higher in the mutant. During the exponential growth phase of endosperm between 6 d after pollination and 9 d after pollination, the mean cell doubling time, the absolute growth rate and the level of endoreduplication were similar in the two genotypes. However, the entire duration of growth was longer in Mnl compared with mnl, resulting in a significantly higher cell number in the Mnl endosperm. These data correlate with the previously reported peak levels of the Mn1-encoded cell wall invertase-2 （INCW2） at 12 d after pollination in the Mn1 endosperm. A model showing possible crosstalk among cytokinins, cell cycle and cell wall invertase as causal to increased cell number and sink strength of the Mn1 developing endosperm is discussed.展开更多
Pueraria thomsonii has long been used in traditional Chinese medicine.Isoflavonoids are the principle pharmacologically active components,which are primarily observed as glycosyl-conjugates and accumulate in P.thomson...Pueraria thomsonii has long been used in traditional Chinese medicine.Isoflavonoids are the principle pharmacologically active components,which are primarily observed as glycosyl-conjugates and accumulate in P.thomsonii roots.However,the molecular mechanisms underlying the glycosylation processes in(iso)flavonoid biosynthesis have not been thoroughly elucidated.In the current study,an O-glucosyltransferase(PtUGT8)was identified in the medicinal plant P.thomsonii from RNA-seq database.Biochemical assays of the recombinant PtUGT8 showed that it was able to glycosylate chalcone(isoliquiritigenin)at the 4-OH position and glycosylate isoflavones(daidzein,formononetin,and genistein)at the 7-OH or 4′-OH position,exhibiting no enzyme activity to flavonones(liquiritigenin and narigenin)in vitro.The identification of PtUGT8 may provide a useful enzyme catalyst for efficient biotransformation of isoflavones and other natural products for food or pharmacological applications.展开更多
利用1 H NMR、13 C NMR、COSY、HSQC和HMBC等多种核磁共振技术,结合MS技术,确认了皂苷Tb的2个糖基化产物的结构,即偏诺皂苷元-3-O-α-D-葡萄糖-(1→3)-[α-L-鼠李糖-(1→2)]-β-D-葡萄糖苷(1)和偏诺皂苷元-3-O-α-D-葡萄糖-(1→4)-α-D...利用1 H NMR、13 C NMR、COSY、HSQC和HMBC等多种核磁共振技术,结合MS技术,确认了皂苷Tb的2个糖基化产物的结构,即偏诺皂苷元-3-O-α-D-葡萄糖-(1→3)-[α-L-鼠李糖-(1→2)]-β-D-葡萄糖苷(1)和偏诺皂苷元-3-O-α-D-葡萄糖-(1→4)-α-D-葡萄糖-(1→3)-[α-L-鼠李糖-(1→2)]-β-D-葡萄糖苷(2).化合物1和2为新化合物,对其1 H NMR和13 CNMR信号分别进行了全归属和详细分析.展开更多
基金supported in parts by the Ministry of Science and Technology of China(2012CB944802 and 2012AA101103)the National Natural Science Foundation of China(91317305)the Ministry of Agriculture of China(2014ZX08009-003)
文摘As a ubiquitous reaction, glucosylation controls the bioactivity of cytokinins in plant growth and development. Here we show that genetic manipulation of zeatin-O- glucosylation regulates the formation of important agronomic traits in rice by manipulating the expression of OscZOG1 gene, encoding a putative zeatin O-glucosyltransferase. We found that OscZOG~ was preferentially expressed in shoot and root meristematic tissues and nascent organs. The growth of lateral roots was stimulated in the overexpression lines, but inhibited in RNA interference lines. In shoots, knockdown of OscZOG1 expression by RNA interference significantly im- proved tillering, panicle branching, grain number per panicle and seed size, which are important agronomic traits for grain yield. In contrast, constitutive expression of OscZOG1 leads to negative effects on the formation of the grain-yielding traits with a marked increase in the accumulation levels of cis-zeatin O-glucoside （cZOG） in the transgenic rice plants. In this study,our findings demonstrate the feasibility of improving the critical yield-determinant agronomic traits, including tiller number, panicle branches, total grain number per panicle and grain weight by downregulating the expression level of OscZOG1. Our results suggest that modulating the levels of cytokinin glucosylation can function as a fine-tuning switch in regulating the formation of agronomic traits in rice.
基金supported by the Slovenian Research Agency (P1-0212)by the USA-Slovenia Cooperation in Science and Technology (BI-US/06-07-031)
文摘We report here on a comparative developmental profile of plant hormone cytokinins in relation to cell size, cell number and endoreduplicaUon in developing maize caryopsis of a cell wall invertase-deficient miniature1 （mn1） seed mutant and its wild type, Mn1, genotype. Both genotypes showed extremely high levels of total cytokinins during the very early stages of development, followed by a marked and genotype specific reduction. While the decrease of cytokinins in Mn1 was associated with their deactivation by 9-glucosylation, the absolute and the relative part of active cytokinin forms was higher in the mutant. During the exponential growth phase of endosperm between 6 d after pollination and 9 d after pollination, the mean cell doubling time, the absolute growth rate and the level of endoreduplication were similar in the two genotypes. However, the entire duration of growth was longer in Mnl compared with mnl, resulting in a significantly higher cell number in the Mnl endosperm. These data correlate with the previously reported peak levels of the Mn1-encoded cell wall invertase-2 （INCW2） at 12 d after pollination in the Mn1 endosperm. A model showing possible crosstalk among cytokinins, cell cycle and cell wall invertase as causal to increased cell number and sink strength of the Mn1 developing endosperm is discussed.
基金supported by the National Key Research and Development Program of China(Nos.2017YFC1702901 and 2017YFC1701601)CAMS Innovation Fund for Medical Sciences(No.2019-I2M-5-065)。
文摘Pueraria thomsonii has long been used in traditional Chinese medicine.Isoflavonoids are the principle pharmacologically active components,which are primarily observed as glycosyl-conjugates and accumulate in P.thomsonii roots.However,the molecular mechanisms underlying the glycosylation processes in(iso)flavonoid biosynthesis have not been thoroughly elucidated.In the current study,an O-glucosyltransferase(PtUGT8)was identified in the medicinal plant P.thomsonii from RNA-seq database.Biochemical assays of the recombinant PtUGT8 showed that it was able to glycosylate chalcone(isoliquiritigenin)at the 4-OH position and glycosylate isoflavones(daidzein,formononetin,and genistein)at the 7-OH or 4′-OH position,exhibiting no enzyme activity to flavonones(liquiritigenin and narigenin)in vitro.The identification of PtUGT8 may provide a useful enzyme catalyst for efficient biotransformation of isoflavones and other natural products for food or pharmacological applications.
文摘利用1 H NMR、13 C NMR、COSY、HSQC和HMBC等多种核磁共振技术,结合MS技术,确认了皂苷Tb的2个糖基化产物的结构,即偏诺皂苷元-3-O-α-D-葡萄糖-(1→3)-[α-L-鼠李糖-(1→2)]-β-D-葡萄糖苷(1)和偏诺皂苷元-3-O-α-D-葡萄糖-(1→4)-α-D-葡萄糖-(1→3)-[α-L-鼠李糖-(1→2)]-β-D-葡萄糖苷(2).化合物1和2为新化合物,对其1 H NMR和13 CNMR信号分别进行了全归属和详细分析.
基金The National Nature Science Foundation of China(NSFC No.20602040)The scientific and innovation research of college graduate in Jiangsu province(CXLX11_0788)
