Various active components have been extracted from the root of Polygonum cuspidatum. However, the genetic basis for their activity is virtually unknown. In this study, 25600002 short reads （2.3 Gb） of P. cuspidatum ...Various active components have been extracted from the root of Polygonum cuspidatum. However, the genetic basis for their activity is virtually unknown. In this study, 25600002 short reads （2.3 Gb） of P. cuspidatum root transcriptome were obtained via lllumina HiSeq 2000 sequencing. A total of 86418 urtigenes were assembled de novo and annotated. Twelve, 18, 60 and 54 unigenes were respectively mapped to the mevalonic acid （MVA）, methyl-D-erythritol 4-phosphate （MEP）, shikimate and resveratrol biosynthesis pathways, suggesting that they are involved in the biosynthesis of pharmaceutically important anthra- quinone and resveratrol. Eighteen potential UDP-glycosyltransferase unigenes were identified as the candidates most likely to be involved in the biosynthesis of glycosides of secondary metabolites. Identification of relevant genes could be important in eventually increasing the yields of the medicinally useful constituents of the P. cuspidatum root. From the previously published transcriptome data of 19 non-model plant taxa, 1127 shared orthologs were identified and characterized. This information will be very useful for future functional, phylogenetic and evolutionary studies of these plants.展开更多
The high-resolution records of δ18O and snow accumulation variations from the Guliya ice core provide valuable data for research on climatic variations at a decadal resolution during the past 2000 years in China. Bas...The high-resolution records of δ18O and snow accumulation variations from the Guliya ice core provide valuable data for research on climatic variations at a decadal resolution during the past 2000 years in China. Based on the ice core data, five spells have been divided: the warm and wet period before 270 AD, the cold and dry period between 280 and 970 AD, the moderate and dry period between 970 and 1510 AD, the well-defined' Little Ice Age 'with drastic cold-warm fluctuations between 1510 and 1930 AD and the warming period since 1930 AD. According to the combination of temperature and precipitation, cold events (55 times) surpass warm ones (26 times) , and dry events (55 times) surpass wet ones (45 times) . Cold-wet events (14 times) are less than cold-dry ones (16 times) , while warm-wet events (10 times) are more than warm-dry ones (4 times) . If the difference of 2‰ in δ18O (corresponding to 3K in temperature) between two or three adjacent decades is taken as the criterion of it, the abrupt change has taken place 33 times or so since the 3rd century. Among them are four large ones, occurring in 250-280, 550-580, 1220-1260, and 1520-1560 AD respectively. Comparison of the ice core data with the latest comprehensive research results on historical documents of East China shows that the great climatic events appeared simultaneously or at the same age in the ice core record and in the documentary data, suggesting that consistences and similarities in climatic variation among different areas are far away from each other in the lower to mid-latitudes. However, there is a great difference between them during the Medieval Warm Period, which is conspicuous in the historical documents but not in the ice core. In addition, the first cold event of the Little Ice Age on East China was 60 years earlier than that of the Guliya Ice Cap, when the degree of cooling in West China is more intensive than that of East China. But the third cold event in East China lagged behind that in West China during the late 19th century. Th展开更多
Microsoft的 SQL Server 2 0 0 0第一次包含了数据挖掘特性。 Microsoft的数据挖掘解决方案是基于针对指定的数据挖掘的 OL E DB上的。OL E DB是 Microsoft制定的工业标准并被一系列数据挖掘 ISV所支持。这种指定为数据挖掘提出了一种...Microsoft的 SQL Server 2 0 0 0第一次包含了数据挖掘特性。 Microsoft的数据挖掘解决方案是基于针对指定的数据挖掘的 OL E DB上的。OL E DB是 Microsoft制定的工业标准并被一系列数据挖掘 ISV所支持。这种指定为数据挖掘提出了一种新的类 SQL 语言 ,这种语言使数据库开发者能更好地建立数据挖掘的应用。本文给出了一个关于运用 SQL Server 2 0 0 0构建数据挖掘应用的示例。展开更多
基金supported by the National Science and Technology Major Program (Grant No.2008ZX10005-004)
文摘Various active components have been extracted from the root of Polygonum cuspidatum. However, the genetic basis for their activity is virtually unknown. In this study, 25600002 short reads （2.3 Gb） of P. cuspidatum root transcriptome were obtained via lllumina HiSeq 2000 sequencing. A total of 86418 urtigenes were assembled de novo and annotated. Twelve, 18, 60 and 54 unigenes were respectively mapped to the mevalonic acid （MVA）, methyl-D-erythritol 4-phosphate （MEP）, shikimate and resveratrol biosynthesis pathways, suggesting that they are involved in the biosynthesis of pharmaceutically important anthra- quinone and resveratrol. Eighteen potential UDP-glycosyltransferase unigenes were identified as the candidates most likely to be involved in the biosynthesis of glycosides of secondary metabolites. Identification of relevant genes could be important in eventually increasing the yields of the medicinally useful constituents of the P. cuspidatum root. From the previously published transcriptome data of 19 non-model plant taxa, 1127 shared orthologs were identified and characterized. This information will be very useful for future functional, phylogenetic and evolutionary studies of these plants.
基金Project supported by the Ministry of Science and Technology of China and the KZ 951-A1-202-04 project of the Chinese Academy of Sciences.
文摘The high-resolution records of δ18O and snow accumulation variations from the Guliya ice core provide valuable data for research on climatic variations at a decadal resolution during the past 2000 years in China. Based on the ice core data, five spells have been divided: the warm and wet period before 270 AD, the cold and dry period between 280 and 970 AD, the moderate and dry period between 970 and 1510 AD, the well-defined' Little Ice Age 'with drastic cold-warm fluctuations between 1510 and 1930 AD and the warming period since 1930 AD. According to the combination of temperature and precipitation, cold events (55 times) surpass warm ones (26 times) , and dry events (55 times) surpass wet ones (45 times) . Cold-wet events (14 times) are less than cold-dry ones (16 times) , while warm-wet events (10 times) are more than warm-dry ones (4 times) . If the difference of 2‰ in δ18O (corresponding to 3K in temperature) between two or three adjacent decades is taken as the criterion of it, the abrupt change has taken place 33 times or so since the 3rd century. Among them are four large ones, occurring in 250-280, 550-580, 1220-1260, and 1520-1560 AD respectively. Comparison of the ice core data with the latest comprehensive research results on historical documents of East China shows that the great climatic events appeared simultaneously or at the same age in the ice core record and in the documentary data, suggesting that consistences and similarities in climatic variation among different areas are far away from each other in the lower to mid-latitudes. However, there is a great difference between them during the Medieval Warm Period, which is conspicuous in the historical documents but not in the ice core. In addition, the first cold event of the Little Ice Age on East China was 60 years earlier than that of the Guliya Ice Cap, when the degree of cooling in West China is more intensive than that of East China. But the third cold event in East China lagged behind that in West China during the late 19th century. Th
文摘Microsoft的 SQL Server 2 0 0 0第一次包含了数据挖掘特性。 Microsoft的数据挖掘解决方案是基于针对指定的数据挖掘的 OL E DB上的。OL E DB是 Microsoft制定的工业标准并被一系列数据挖掘 ISV所支持。这种指定为数据挖掘提出了一种新的类 SQL 语言 ,这种语言使数据库开发者能更好地建立数据挖掘的应用。本文给出了一个关于运用 SQL Server 2 0 0 0构建数据挖掘应用的示例。
