The Experts below are selected from a list of 8424 Experts worldwide ranked by ideXlab platform
Raymond P Guries - One of the best experts on this subject based on the ideXlab platform.
-
Elm genetic diversity and hybridization in the presence of Dutch elm disease
2017Co-Authors: Johanne Brunet, Raymond P GuriesAbstract:The impact of Dutch elm disease (DED) on the genetic diversity of slippery elm (Ulmus rubra) is summarized and its potential impact on the genetic diversity of other North American native elms, American elm (U. americana), rock elm (U. thomasii), winged elm (U. alata), cedar elm (U. crassifolia), and September elm (U. serotina), is discussed. The potential for hybridization between the introduced Siberian elm U. Pumila and the native North American elms is considered given previous findings with U. rubra. We do not expect DED to reduce the genetic diversity of these native elms. The only exception may be U. serotina if its restricted range leads to genetic discontinuities among populations. We do not expect hybridization between U. americana and U. Pumila due to incompatibility barriers, but hybridization between U. Pumila and other native elms appears more likely and could have negative effects on the long term conservation of these species. This information is timely given the current efforts to restore American elm across the U.S. landscape.
-
ORIGINAL ARTICLE: The extent of hybridization and its impact on the genetic diversity and population structure of an invasive tree, Ulmus Pumila (Ulmaceae)
Evolutionary Applications, 2010Co-Authors: Juan Zalapa, Johanne Brunet, Raymond P GuriesAbstract:Ulmus Pumila is considered an invasive tree in 41 of the United States. In this study, we examined the extent of hybridization in naturalized populations of U. Pumila, its impact on genetic diversity and genetic structure and its potential role in explaining the invasion process of U. Pumila. Genetic analyses indicated widespread hybridization with native Ulmus rubra in naturalized U. Pumila populations. Hybridization increased the genetic diversity of U. Pumila populations and affected their genetic structure. The level of genetic diversity in ‘mature’ accessions, many of which may represent original plantings throughout the USA, was high and similar to the diversity of East Asian accessions. Hybridization with the native red elm may play an important role in the success of Siberian elm as an invader in temperate regions of the USA.
-
patterns of hybridization and introgression between invasive ulmus Pumila ulmaceae and native u rubra
American Journal of Botany, 2009Co-Authors: Johanne Brunet, Juan Zalapa, Raymond P GuriesAbstract:Natural hybridization between introduced species and their native congeners occurs frequently and can create serious conservation concerns. Ulmus Pumila (Siberian elm) is an introduced Asian elm species that has naturalized in the United States and is now considered invasive in 41 states. Red elm (U. rubra), a native to the eastern United States, often occurs in sympatry with Siberian elm, and the two species are thought to hybridize. Here, we genetically characterized reference populations of the two elm species to identify species-specific microsatellite alleles. These markers were used to classify individuals in putative hybrid zones as parental species or hybrids, assess the extent of hybridization, and track patterns of introgression. We identified nine U. rubra, 32 U. Pumila, and 51 hybrid individuals in our hybrid zones. Of the 51 hybrids, 35 were classified as first-generation hybrids and 16 as backcrosses. The majority of the backcrosses (88%) were introgressed toward U. Pumila. Our classification of genotypes was consistent whether we used manual classification, principal coordinate analyses or Bayesian clustering. We observed greater genetic diversity and new combination of alleles in the hybrids. Our study indicates widespread hybridization between U. Pumila and U. rubra and an asymmetric pattern of introgression toward U. Pumila.
-
Isolation and characterization of microsatellite markers for red elm (Ulmus rubra Muhl.) and cross-species amplification with Siberian elm (Ulmus Pumila L.).
Molecular Ecology Resources, 2008Co-Authors: Juan Zalapa, Johanne Brunet, Raymond P GuriesAbstract:Ulmus Pumila is an elm species, non-native to the USA that hybridizes with Ulmus rubra. In order to study the genetic structure and hybridization patterns between these two elm species, we developed 15 primer pairs for microsatellite loci in U. rubra and tested their cross-amplification in U. Pumila. All 15 primers amplified in both species, 11 of which possessed species-specific alleles. Eight loci were polymorphic in U. Pumila and eight in U. rubra, each with two to eight alleles per locus. In addition, five primer pairs previously developed in U. laevis and U. carpinifolia (syn. U. minor) cross-amplified and showed polymorphic loci in U. Pumila and/or U. rubra. These markers will facilitate the study of genetic structure and gene flow between U. rubra and exotic, invasive U. Pumila.
Juan Zalapa - One of the best experts on this subject based on the ideXlab platform.
-
ORIGINAL ARTICLE: The extent of hybridization and its impact on the genetic diversity and population structure of an invasive tree, Ulmus Pumila (Ulmaceae)
Evolutionary Applications, 2010Co-Authors: Juan Zalapa, Johanne Brunet, Raymond P GuriesAbstract:Ulmus Pumila is considered an invasive tree in 41 of the United States. In this study, we examined the extent of hybridization in naturalized populations of U. Pumila, its impact on genetic diversity and genetic structure and its potential role in explaining the invasion process of U. Pumila. Genetic analyses indicated widespread hybridization with native Ulmus rubra in naturalized U. Pumila populations. Hybridization increased the genetic diversity of U. Pumila populations and affected their genetic structure. The level of genetic diversity in ‘mature’ accessions, many of which may represent original plantings throughout the USA, was high and similar to the diversity of East Asian accessions. Hybridization with the native red elm may play an important role in the success of Siberian elm as an invader in temperate regions of the USA.
-
patterns of hybridization and introgression between invasive ulmus Pumila ulmaceae and native u rubra
American Journal of Botany, 2009Co-Authors: Johanne Brunet, Juan Zalapa, Raymond P GuriesAbstract:Natural hybridization between introduced species and their native congeners occurs frequently and can create serious conservation concerns. Ulmus Pumila (Siberian elm) is an introduced Asian elm species that has naturalized in the United States and is now considered invasive in 41 states. Red elm (U. rubra), a native to the eastern United States, often occurs in sympatry with Siberian elm, and the two species are thought to hybridize. Here, we genetically characterized reference populations of the two elm species to identify species-specific microsatellite alleles. These markers were used to classify individuals in putative hybrid zones as parental species or hybrids, assess the extent of hybridization, and track patterns of introgression. We identified nine U. rubra, 32 U. Pumila, and 51 hybrid individuals in our hybrid zones. Of the 51 hybrids, 35 were classified as first-generation hybrids and 16 as backcrosses. The majority of the backcrosses (88%) were introgressed toward U. Pumila. Our classification of genotypes was consistent whether we used manual classification, principal coordinate analyses or Bayesian clustering. We observed greater genetic diversity and new combination of alleles in the hybrids. Our study indicates widespread hybridization between U. Pumila and U. rubra and an asymmetric pattern of introgression toward U. Pumila.
-
Isolation and characterization of microsatellite markers for red elm (Ulmus rubra Muhl.) and cross-species amplification with Siberian elm (Ulmus Pumila L.).
Molecular Ecology Resources, 2008Co-Authors: Juan Zalapa, Johanne Brunet, Raymond P GuriesAbstract:Ulmus Pumila is an elm species, non-native to the USA that hybridizes with Ulmus rubra. In order to study the genetic structure and hybridization patterns between these two elm species, we developed 15 primer pairs for microsatellite loci in U. rubra and tested their cross-amplification in U. Pumila. All 15 primers amplified in both species, 11 of which possessed species-specific alleles. Eight loci were polymorphic in U. Pumila and eight in U. rubra, each with two to eight alleles per locus. In addition, five primer pairs previously developed in U. laevis and U. carpinifolia (syn. U. minor) cross-amplified and showed polymorphic loci in U. Pumila and/or U. rubra. These markers will facilitate the study of genetic structure and gene flow between U. rubra and exotic, invasive U. Pumila.
Johanne Brunet - One of the best experts on this subject based on the ideXlab platform.
-
Intra- and interspecific hybridization in invasive Siberian elm
Biological Invasions, 2017Co-Authors: Heidi Hirsch, Johanne Brunet, Juan E. Zalapa, Henrik Wehrden, Matthias Hartmann, Carolin Kleindienst, Brandon Schlautman, Evsey Kosman, Karsten Wesche, Daniel RenisonAbstract:Hybridization creates unique allele combinations which can facilitate the evolution of invasiveness. Frequent interspecific hybridization between the Siberian elm, Ulmus Pumila , and native elm species has been detected in the Midwestern United States, Italy and Spain. However, Ulmus Pumila also occurs in the western United States and Argentina, regions where no native elm species capable of hybridizing with it occurs. We examined whether inter- or intraspecific hybridization could be detected in these regions. Nuclear markers and the program STRUCTURE helped detect interspecific hybridization and determine the population genetic structure in both the native and the two non-native ranges. Chloroplast markers identified sources of introduction into these two non-native ranges. No significant interspecific hybridization was detected between U. Pumila and U. rubra in the western United States or between U. Pumila and U. minor in Argentina and vice versa. However, the genetic findings supported the presence of intraspecific hybridization and high levels of genetic diversity in both non-native ranges. The evidence presented for intraspecific hybridization in the current study, combined with reports of interspecific hybridization from previous studies, identifies elm as a genus where both inter- and intraspecific hybridization may occur and help maintain high levels of genetic diversity potentially associated with invasiveness.
-
Elm genetic diversity and hybridization in the presence of Dutch elm disease
2017Co-Authors: Johanne Brunet, Raymond P GuriesAbstract:The impact of Dutch elm disease (DED) on the genetic diversity of slippery elm (Ulmus rubra) is summarized and its potential impact on the genetic diversity of other North American native elms, American elm (U. americana), rock elm (U. thomasii), winged elm (U. alata), cedar elm (U. crassifolia), and September elm (U. serotina), is discussed. The potential for hybridization between the introduced Siberian elm U. Pumila and the native North American elms is considered given previous findings with U. rubra. We do not expect DED to reduce the genetic diversity of these native elms. The only exception may be U. serotina if its restricted range leads to genetic discontinuities among populations. We do not expect hybridization between U. americana and U. Pumila due to incompatibility barriers, but hybridization between U. Pumila and other native elms appears more likely and could have negative effects on the long term conservation of these species. This information is timely given the current efforts to restore American elm across the U.S. landscape.
-
Hybridization and introgression between the exotic Siberian elm, Ulmus Pumila, and the native Field elm, U. minor, in Italy
Biological Invasions, 2013Co-Authors: Johanne Brunet, Juan E. Zalapa, Francesco Pecori, Alberto SantiniAbstract:In response to the first Dutch elm disease (DED) pandemic, Siberian elm, Ulmus Pumila , was planted to replace the native elm, U. minor , in Italy. The potential for hybridization between these two species is high and repeated hybridization could result in the genetic swamping of the native species and facilitate the evolution of invasiveness in the introduced species. We used genetic markers to examine the extent of hybridization between these two species and to determine the pattern of introgression. We quantified and compared the level of genetic diversity between the hybrids and the two parental species. Hybrids between U. Pumila and U. minor were common. The pattern of introgression was not as strongly biased towards U. Pumila as was previously observed for hybrids between U. rubra and U. Pumila in the United States. The levels of heterozygosity were similar between U. minor and the hybrids and both groups had higher levels of heterozygosity relative to U. Pumila . The programs Structure and NewHybrids indicated the presence of first- (F_1) and second- generation (F_2) hybrids and of backcrosses in the hybrid population. The presence of healthy DED resistant U. minor individuals combined with the self-compatibility of U. minor could help explain the presence of F_2 individuals in Italy. The presence of F_2 individuals, where most of the variability present in the hybrids will be released, could facilitate rapid evolution and the potential evolution of invasiveness of U. Pumila in Italy.
-
ORIGINAL ARTICLE: The extent of hybridization and its impact on the genetic diversity and population structure of an invasive tree, Ulmus Pumila (Ulmaceae)
Evolutionary Applications, 2010Co-Authors: Juan Zalapa, Johanne Brunet, Raymond P GuriesAbstract:Ulmus Pumila is considered an invasive tree in 41 of the United States. In this study, we examined the extent of hybridization in naturalized populations of U. Pumila, its impact on genetic diversity and genetic structure and its potential role in explaining the invasion process of U. Pumila. Genetic analyses indicated widespread hybridization with native Ulmus rubra in naturalized U. Pumila populations. Hybridization increased the genetic diversity of U. Pumila populations and affected their genetic structure. The level of genetic diversity in ‘mature’ accessions, many of which may represent original plantings throughout the USA, was high and similar to the diversity of East Asian accessions. Hybridization with the native red elm may play an important role in the success of Siberian elm as an invader in temperate regions of the USA.
-
patterns of hybridization and introgression between invasive ulmus Pumila ulmaceae and native u rubra
American Journal of Botany, 2009Co-Authors: Johanne Brunet, Juan Zalapa, Raymond P GuriesAbstract:Natural hybridization between introduced species and their native congeners occurs frequently and can create serious conservation concerns. Ulmus Pumila (Siberian elm) is an introduced Asian elm species that has naturalized in the United States and is now considered invasive in 41 states. Red elm (U. rubra), a native to the eastern United States, often occurs in sympatry with Siberian elm, and the two species are thought to hybridize. Here, we genetically characterized reference populations of the two elm species to identify species-specific microsatellite alleles. These markers were used to classify individuals in putative hybrid zones as parental species or hybrids, assess the extent of hybridization, and track patterns of introgression. We identified nine U. rubra, 32 U. Pumila, and 51 hybrid individuals in our hybrid zones. Of the 51 hybrids, 35 were classified as first-generation hybrids and 16 as backcrosses. The majority of the backcrosses (88%) were introgressed toward U. Pumila. Our classification of genotypes was consistent whether we used manual classification, principal coordinate analyses or Bayesian clustering. We observed greater genetic diversity and new combination of alleles in the hybrids. Our study indicates widespread hybridization between U. Pumila and U. rubra and an asymmetric pattern of introgression toward U. Pumila.
Mami Yamazaki - One of the best experts on this subject based on the ideXlab platform.
-
function of ap2 erf transcription factors involved in the regulation of specialized metabolism in ophiorrhiza Pumila revealed by transcriptomics and metabolomics
Frontiers in Plant Science, 2016Co-Authors: Nirin Udomsom, Kazuki Saito, Ryo Nakabayashi, Amit Rai, Hideyuki Suzuki, Jun Okuyama, Ryosuke Imai, Tetsuya Mori, Mami YamazakiAbstract:The hairy roots (HR) of Ophiorrhiza Pumila produce camptothecin (CPT), a monoterpenoid indole alkaloid used as a precursor in the synthesis of chemotherapeutic drugs. O. Pumila HR culture is considered as a promising alternative source of CPT, however, the knowledge about the biosynthetic pathway and regulatory mechanism is still limited. In this study, five genes that encode AP2/ERF transcription factors, namely OpERF1 to OpERF5, were isolated from HR of O. Pumila. Phylogenetic analysis of AP2/ERF protein sequences suggested the close evolutionary relationship of OpERF1 with stress-responsive ERF factors in Arabidopsis and of OpERF2 with ERF factors reported to regulate alkaloid production, such as ORCA3 in Catharanthus roseus, NIC2 locus ERFs in tobacco, and JRE4 in tomato. We generated the transgenic HR lines of O. Pumila, ERF1i and ERF2i, in which the expression of OpERF1 and OpERF2, respectively, was suppressed using RNA interference technique. The transcriptome and metabolome of these suppressed HR were analyzed for functional characterization of OpERF1 and OpERF2. Although significant changes were not observed in the metabolome, including CPT and related compounds, the suppression of OpERF2 resulted in reduced expression of genes in the 2-C-methyl- D -erythritol 4-phosphate and secologanin-strictosidine pathways, which supply a precursor, strictosidine, for CPT biosynthesis. Furthermore, while it was not conclusive for OpERF1, enrichment analysis of differentially expressed genes in the suppressed HR showed that the gene ontology terms for oxidation-reduction, presumably involved in secondary metabolite pathways, were enriched in the ERF2i downregulated gene set. These results suggest a positive role of OpERF2 in regulating specialized metabolism in O. Pumila.
-
Function of AP2/ERF transcription factors involved in the regulation of specialized metabolism in <i>Ophiorrhiza Pumila</i> revealed by transcriptomics and metabolomics
Frontiers Media S.A., 2016Co-Authors: Nirin Udomsom, Kazuki Saito, Ryo Nakabayashi, Amit Rai, Hideyuki Suzuki, Jun Okuyama, Ryosuke Imai, Tetsuya Mori, Mami YamazakiAbstract:The hairy roots (HR) of Ophiorrhiza Pumila produce camptothecin (CPT), a monoterpenoid indole alkaloid used as a precursor in the synthesis of chemotherapeutic drugs. O. Pumila HR culture is considered as a promising alternative source of CPT, however, the knowledge about the biosynthetic pathway and regulatory mechanism is still limited. In this study, five genes that encode AP2/ERF transcription factors, namely OpERF1 to OpERF5, were isolated from HR of O. Pumila. Phylogenetic analysis of AP2/ERF protein sequences suggested the close evolutionary relationship of OpERF1 with stress-responsive ERF factors in Arabidopsis and of OpERF2 with ERF factors reported to regulate alkaloid production, such as ORCA3 in Catharanthus roseus, NIC2 locus ERFs in tobacco, and JRE4 in tomato. We generated the transgenic HR lines of O. Pumila, ERF1i and ERF2i, in which the expression of OpERF1 and OpERF2, respectively, was suppressed using RNA interference technique. The transcriptome and metabolome of these suppressed HR were analyzed for functional characterization of OpERF1 and OpERF2. Although significant changes were not observed in the metabolome, including CPT and related compounds, the suppression of OpERF2 resulted in reduced expression of genes in the 2-C-methyl- D -erythritol 4-phosphate and secologanin-strictosidine pathways, which supply a precursor, strictosidine, for CPT biosynthesis. Furthermore, while it was not conclusive for OpERF1, enrichment analysis of differentially expressed genes in the suppressed HR showed that the gene ontology terms for oxidation-reduction, presumably involved in secondary metabolite pathways, were enriched in the ERF2i downregulated gene set. These results suggest a positive role of OpERF2 in regulating specialized metabolism in O. Pumila
-
coupling deep transcriptome analysis with untargeted metabolic profiling in ophiorrhiza Pumila to further the understanding of the biosynthesis of the anti cancer alkaloid camptothecin and anthraquinones
Plant and Cell Physiology, 2013Co-Authors: Mami Yamazaki, Yasuyo Yamazaki, Keiichi Mochida, Takashi Asano, Ryo Nakabayashi, Motoaki Chiba, Nirin Udomson, Dayan B Goodenowe, Ushio SankawaAbstract:The Rubiaceae species, Ophiorrhiza Pumila, accumulates camptothecin, an anti-cancer alkaloid with a potent DNA topoisomerase I inhibitory activity, as well as anthraquinones that are derived from the combination of the isochorismate and hemiterpenoid pathways. The biosynthesis of these secondary products is active in O. Pumila hairy roots yet very low in cell suspension culture. Deep transcriptome analysis was conducted in O. Pumila hairy roots and cell suspension cultures using the Illumina platform, yielding a total of 2 Gb of sequence for each sample. We generated a hybrid transcriptome assembly of O. Pumila using the Illumina-derived short read sequences and conventional Sanger-derived expressed sequence tag clones derived from a full-length cDNA library constructed using RNA from hairy roots. Among 35,608 non-redundant unigenes, 3,649 were preferentially expressed in hairy roots compared with cell suspension culture. Candidate genes involved in the biosynthetic pathway for the monoterpenoid indole alkaloid camptothecin were identified; specifically, genes involved in post-strictosamide biosynthetic events and genes involved in the biosynthesis of anthraquinones and chlorogenic acid. Untargeted metabolomic analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) indicated that most of the proposed intermediates in the camptothecin biosynthetic pathway accumulated in hairy roots in a preferential manner compared with cell suspension culture. In addition, a number of anthraquinones and chlorogenic acid preferentially accumulated in hairy roots compared with cell suspension culture. These results suggest that deep transcriptome and metabolome data sets can facilitate the identification of genes and intermediates involved in the biosynthesis of secondary products including camptothecin in O. Pumila.
-
Metabolite profiling of alkaloids and strictosidine synthase activity in camptothecin producing plants.
Phytochemistry, 2003Co-Authors: Yasuyo Yamazaki, Akiko Urano, Hiroshi Sudo, Mariko Kitajima, Hiromitsu Takayama, Mami Yamazaki, Norio Aimi, Kazuki SaitoAbstract:Camptothecin derivatives are clinically used anti-neoplastic alkaloids that biogenetically belong to monoterpenoid indole alkaloids. Camptothecin-related alkaloids from the methanol extracts of Ophiorrhiza Pumila, Camptotheca acuminata and Nothapodytes foetida plants were profiled and identified using a reverse-phase high performance liquid chromatography coupled with on-line photodiode array detection and electrospray-ionization ion-trap mass spectrometry. A natural 10-glycosyloxy camptothecin, chaboside, was accumulated in tissues of O. Pumila but not in C. acuminata and N. foetida. Anthraquinones regarded as phytoalexins were present in the extracts of hairy roots and calli but not in the differentiated plants of O. Pumila. These findings demonstrated a remarkable difference in the constituents between the differentiated plants and the hairy roots or calli tissues. The activity of strictosidine synthase, a key enzyme of camptothecin biosynthesis, was detected in the protein extracts of stems and roots of O. Pumila, being correlated with the pattern of strictosidine synthase mRNA expression.
Kazuki Saito - One of the best experts on this subject based on the ideXlab platform.
-
function of ap2 erf transcription factors involved in the regulation of specialized metabolism in ophiorrhiza Pumila revealed by transcriptomics and metabolomics
Frontiers in Plant Science, 2016Co-Authors: Nirin Udomsom, Kazuki Saito, Ryo Nakabayashi, Amit Rai, Hideyuki Suzuki, Jun Okuyama, Ryosuke Imai, Tetsuya Mori, Mami YamazakiAbstract:The hairy roots (HR) of Ophiorrhiza Pumila produce camptothecin (CPT), a monoterpenoid indole alkaloid used as a precursor in the synthesis of chemotherapeutic drugs. O. Pumila HR culture is considered as a promising alternative source of CPT, however, the knowledge about the biosynthetic pathway and regulatory mechanism is still limited. In this study, five genes that encode AP2/ERF transcription factors, namely OpERF1 to OpERF5, were isolated from HR of O. Pumila. Phylogenetic analysis of AP2/ERF protein sequences suggested the close evolutionary relationship of OpERF1 with stress-responsive ERF factors in Arabidopsis and of OpERF2 with ERF factors reported to regulate alkaloid production, such as ORCA3 in Catharanthus roseus, NIC2 locus ERFs in tobacco, and JRE4 in tomato. We generated the transgenic HR lines of O. Pumila, ERF1i and ERF2i, in which the expression of OpERF1 and OpERF2, respectively, was suppressed using RNA interference technique. The transcriptome and metabolome of these suppressed HR were analyzed for functional characterization of OpERF1 and OpERF2. Although significant changes were not observed in the metabolome, including CPT and related compounds, the suppression of OpERF2 resulted in reduced expression of genes in the 2-C-methyl- D -erythritol 4-phosphate and secologanin-strictosidine pathways, which supply a precursor, strictosidine, for CPT biosynthesis. Furthermore, while it was not conclusive for OpERF1, enrichment analysis of differentially expressed genes in the suppressed HR showed that the gene ontology terms for oxidation-reduction, presumably involved in secondary metabolite pathways, were enriched in the ERF2i downregulated gene set. These results suggest a positive role of OpERF2 in regulating specialized metabolism in O. Pumila.
-
Function of AP2/ERF transcription factors involved in the regulation of specialized metabolism in <i>Ophiorrhiza Pumila</i> revealed by transcriptomics and metabolomics
Frontiers Media S.A., 2016Co-Authors: Nirin Udomsom, Kazuki Saito, Ryo Nakabayashi, Amit Rai, Hideyuki Suzuki, Jun Okuyama, Ryosuke Imai, Tetsuya Mori, Mami YamazakiAbstract:The hairy roots (HR) of Ophiorrhiza Pumila produce camptothecin (CPT), a monoterpenoid indole alkaloid used as a precursor in the synthesis of chemotherapeutic drugs. O. Pumila HR culture is considered as a promising alternative source of CPT, however, the knowledge about the biosynthetic pathway and regulatory mechanism is still limited. In this study, five genes that encode AP2/ERF transcription factors, namely OpERF1 to OpERF5, were isolated from HR of O. Pumila. Phylogenetic analysis of AP2/ERF protein sequences suggested the close evolutionary relationship of OpERF1 with stress-responsive ERF factors in Arabidopsis and of OpERF2 with ERF factors reported to regulate alkaloid production, such as ORCA3 in Catharanthus roseus, NIC2 locus ERFs in tobacco, and JRE4 in tomato. We generated the transgenic HR lines of O. Pumila, ERF1i and ERF2i, in which the expression of OpERF1 and OpERF2, respectively, was suppressed using RNA interference technique. The transcriptome and metabolome of these suppressed HR were analyzed for functional characterization of OpERF1 and OpERF2. Although significant changes were not observed in the metabolome, including CPT and related compounds, the suppression of OpERF2 resulted in reduced expression of genes in the 2-C-methyl- D -erythritol 4-phosphate and secologanin-strictosidine pathways, which supply a precursor, strictosidine, for CPT biosynthesis. Furthermore, while it was not conclusive for OpERF1, enrichment analysis of differentially expressed genes in the suppressed HR showed that the gene ontology terms for oxidation-reduction, presumably involved in secondary metabolite pathways, were enriched in the ERF2i downregulated gene set. These results suggest a positive role of OpERF2 in regulating specialized metabolism in O. Pumila
-
Metabolite profiling of alkaloids and strictosidine synthase activity in camptothecin producing plants.
Phytochemistry, 2003Co-Authors: Yasuyo Yamazaki, Akiko Urano, Hiroshi Sudo, Mariko Kitajima, Hiromitsu Takayama, Mami Yamazaki, Norio Aimi, Kazuki SaitoAbstract:Camptothecin derivatives are clinically used anti-neoplastic alkaloids that biogenetically belong to monoterpenoid indole alkaloids. Camptothecin-related alkaloids from the methanol extracts of Ophiorrhiza Pumila, Camptotheca acuminata and Nothapodytes foetida plants were profiled and identified using a reverse-phase high performance liquid chromatography coupled with on-line photodiode array detection and electrospray-ionization ion-trap mass spectrometry. A natural 10-glycosyloxy camptothecin, chaboside, was accumulated in tissues of O. Pumila but not in C. acuminata and N. foetida. Anthraquinones regarded as phytoalexins were present in the extracts of hairy roots and calli but not in the differentiated plants of O. Pumila. These findings demonstrated a remarkable difference in the constituents between the differentiated plants and the hairy roots or calli tissues. The activity of strictosidine synthase, a key enzyme of camptothecin biosynthesis, was detected in the protein extracts of stems and roots of O. Pumila, being correlated with the pattern of strictosidine synthase mRNA expression.
