The Experts below are selected from a list of 366 Experts worldwide ranked by ideXlab platform
Elizabeth A. Zimmer - One of the best experts on this subject based on the ideXlab platform.
-
Transcriptome analysis of the Curry Tree (Bergera koenigii L., Rutaceae) during leaf development
Scientific Reports, 2019Co-Authors: Vikram S. Shivakumar, Gabriel Johnson, Elizabeth A. ZimmerAbstract:The Curry Tree ( Bergera koenigii L.) is a widely cultivated plant used in South Asian cooking. Next-generation sequencing was used to generate the transcriptome of the Curry leaf to detect changes in gene expression during leaf development, such as those genes involved in the production of oils which lend the leaf its characteristic taste, aroma, and medicinal properties. Using abundance estimation (RSEM) and differential expression analysis, genes that were significantly differentially expressed were identified. The transcriptome was annotated with BLASTx using the non-redundant (nr) protein database, and Gene Ontology (GO) terms were assigned based on the top BLAST hit using Blast2GO. Lastly, functional enrichment of the assigned GO terms was analyzed for genes that were significantly differentially expressed. Of the most enriched GO categories, pathways involved in cell wall, membrane, and lignin synthesis were found to be most upregulated in immature leaf tissue, possibly due to the growth and expansion of the leaf tissue. Terpene synthases, which synthesize monoterpenes and sesquiterpenes, which comprise much of the Curry essential oil, were found to be significantly upregulated in mature leaf tissue, suggesting that oil production increases later in leaf development. Enzymes involved in pigment production were also significantly upregulated in mature leaves. The findings were based on computational estimates of gene expression from RNA-seq data, and further study is warranted to validate these results using targeted techniques, such as quantitative PCR.
Vikram S. Shivakumar - One of the best experts on this subject based on the ideXlab platform.
-
Transcriptome analysis of the Curry Tree (Bergera koenigii L., Rutaceae) during leaf development
Scientific Reports, 2019Co-Authors: Vikram S. Shivakumar, Gabriel Johnson, Elizabeth A. ZimmerAbstract:The Curry Tree ( Bergera koenigii L.) is a widely cultivated plant used in South Asian cooking. Next-generation sequencing was used to generate the transcriptome of the Curry leaf to detect changes in gene expression during leaf development, such as those genes involved in the production of oils which lend the leaf its characteristic taste, aroma, and medicinal properties. Using abundance estimation (RSEM) and differential expression analysis, genes that were significantly differentially expressed were identified. The transcriptome was annotated with BLASTx using the non-redundant (nr) protein database, and Gene Ontology (GO) terms were assigned based on the top BLAST hit using Blast2GO. Lastly, functional enrichment of the assigned GO terms was analyzed for genes that were significantly differentially expressed. Of the most enriched GO categories, pathways involved in cell wall, membrane, and lignin synthesis were found to be most upregulated in immature leaf tissue, possibly due to the growth and expansion of the leaf tissue. Terpene synthases, which synthesize monoterpenes and sesquiterpenes, which comprise much of the Curry essential oil, were found to be significantly upregulated in mature leaf tissue, suggesting that oil production increases later in leaf development. Enzymes involved in pigment production were also significantly upregulated in mature leaves. The findings were based on computational estimates of gene expression from RNA-seq data, and further study is warranted to validate these results using targeted techniques, such as quantitative PCR.
Krishna Kumar - One of the best experts on this subject based on the ideXlab platform.
-
First Report of Stem Rot Caused by Athelia rolfsii on Curry Leaf Tree (Murraya koenigii) in Tripura, India.
Plant disease, 2020Co-Authors: Deeba Kamil, Krishna Kumar, Amar Bahadur, Presenjit Debnath, Anjali Kumari, Shiv Pratap Choudhary, Prameeladevi ThokalaAbstract:Murraya koenigii is an important medicinal plant of India and commonly known as Curry leaf Tree grown in tropical and subtropical regions. The leaves of Curry Tree are used as a herb due to the presence of following important active constituent bismahanine, murrayanine, murrayafoline-A, bi-koeniquinone-A, murrayazolidine etc. (Jain et al. 2017). During mid-July 2019, stem rot disease symptoms were observed on Curry leaf Trees at the College of Agriculture, Lembucherra, Tripura (India). The disease symptoms consisted of rotting, wilting and blighting with disease incidence ranging from 8 to 10%. Initially, infected plants gradually withered and white mycelia mats appeared on the surface of the lower stem at the soil line. Infected stem samples were collected and surface was sterilized with 0.25% sodium hypochlorite for 1 min, washed thrice with sterilized distilled water and placed in Petri plates containing 2% water agar. After three days of incubation at 26°C, hyphae produced from plant bits were transferred into Petri plates containing potato dextrose agar. Ten isolates were collected from the diseases samples. Pure cultures were obtained as abundant, aerial and white mycelia with round to irregular sclerotia of 0.8 to 1.5 mm in diam. The sclerotia were initially white in color but later turned into brown color. The pathogen was identified as Athelia rolfsii based on morphology (Aycock 1966). To confirm the identification, the genomic DNA was extracted from a mycelia mat of the isolates using ZR fungal/Bacterial DNA miniprep kit (Irvine, CA) and the internal transcribed spacer (ITS) region of rDNA was amplified using the universal primers, ITS1 and ITS4 (White et al. 1990). A 550 bp PCR product was sequenced and showed 99% similarity with Athelia rolfsii isolate (GenBank accession MH854711).The generated sequence was submitted to GenBank (Accession MT535585). After identification of the pathogen a pot experiment was conducted to confirm the pathogenicity. Earthen pots (29 cm. diam.) were filled with sterilized soil and kept in a green house. Ten Curry leaf plants (50 days old) were grown from seed in the separate pot were inoculated with 15-day old mycelia mats prepared in potato dextrose broth. The stem of each Curry plant were artificially injured with the help of sterile blade and wrapped with moistened sterilized cotton containing the mycelial mat. Five Curry leaf plants artificially injured and inoculated with sterilized distilled water were used as control. The Earthen pots with plants were individually covered with plastic bags and kept in the green house at 26°C for approximately 15 days. The inoculated plants started showing symptoms of stem rot six days after inoculation and started drying onward. The symptoms of stem rot on the inoculated plants were similar to those observed in the field. The fungus was re-isolated from the inoculated plants and A. rolfsii identification was confirmed based on morphology. No symptoms were observed on the control plants. The obtained culture was deposited in the Indian Type Culture Collection, Division of Plant Pathology, ICAR - Indian Agricultural Research Institute, New Delhi, India (ITC-8666). To the best of our knowledge this is the first report of stem rot disease of Curry leaf plant caused by A. rolfsii in India and worldwide. Due to medicinal, flavour and aroma properties, it is regularly used in India. Curry leaf plant is regularly used as a medical herb in India and therefore this disease poses a significant risk to production.
-
Transcriptomic insight into terpenoid and carbazole alkaloid biosynthesis, and functional characterization of two terpene synthases in Curry Tree (Murraya koenigii)
Scientific Reports, 2017Co-Authors: Seema Meena, Sarma Rajeev Kumar, Varun Dwivedi, Anup Kumar Singh, Chandan S. Chanotiya, Md. Qussen Akhtar, Krishna Kumar, Ajit Kumar Shasany, Dinesh A. NagegowdaAbstract:Curry Tree ( Murraya koenigii L.) is a rich source of aromatic terpenes and pharmacologically important carbazole alkaloids. Here, M. koenigii leaf transcriptome was generated to gain insight into terpenoid and alkaloid biosynthesis. Analysis of de novo assembled contigs yielded genes for terpene backbone biosynthesis and terpene synthases. Also, gene families possibly involved in carbazole alkaloid formation were identified that included polyketide synthases, prenyltransferases, methyltransferases and cytochrome P450s. Further, two genes encoding terpene synthases (MkTPS1 and MkTPS2) with highest in silico transcript abundance were cloned and functionally characterized to determine their involvement in leaf volatile formation. Subcellular localization using GFP fusions revealed the plastidial and cytosolic localization of MkTPS1 and MkTPS2, respectively. Enzymatic characterization demonstrated the monoterpene synthase activity of recombinant MkTPS1, which produced primarily (−)-sabinene from geranyl diphosphate (GPP). Recombinant MkTPS2 exhibited sesquiterpene synthase activity and formed ( E,E )-α-farnesene as the major product from farnesyl diphosphate (FPP). Moreover, mRNA expression and leaf volatile analyses indicated that MkTPS1 accounts for (−)-sabinene emitted by M. koenigii leaves. Overall, the transcriptome data generated in this study will be a great resource and the start point for characterizing genes involved in the biosynthetic pathway of medicinally important carbazole alkaloids.
Dinesh A. Nagegowda - One of the best experts on this subject based on the ideXlab platform.
-
Transcriptomic insight into terpenoid and carbazole alkaloid biosynthesis, and functional characterization of two terpene synthases in Curry Tree (Murraya koenigii)
Scientific Reports, 2017Co-Authors: Seema Meena, Sarma Rajeev Kumar, Varun Dwivedi, Anup Kumar Singh, Chandan S. Chanotiya, Md. Qussen Akhtar, Krishna Kumar, Ajit Kumar Shasany, Dinesh A. NagegowdaAbstract:Curry Tree ( Murraya koenigii L.) is a rich source of aromatic terpenes and pharmacologically important carbazole alkaloids. Here, M. koenigii leaf transcriptome was generated to gain insight into terpenoid and alkaloid biosynthesis. Analysis of de novo assembled contigs yielded genes for terpene backbone biosynthesis and terpene synthases. Also, gene families possibly involved in carbazole alkaloid formation were identified that included polyketide synthases, prenyltransferases, methyltransferases and cytochrome P450s. Further, two genes encoding terpene synthases (MkTPS1 and MkTPS2) with highest in silico transcript abundance were cloned and functionally characterized to determine their involvement in leaf volatile formation. Subcellular localization using GFP fusions revealed the plastidial and cytosolic localization of MkTPS1 and MkTPS2, respectively. Enzymatic characterization demonstrated the monoterpene synthase activity of recombinant MkTPS1, which produced primarily (−)-sabinene from geranyl diphosphate (GPP). Recombinant MkTPS2 exhibited sesquiterpene synthase activity and formed ( E,E )-α-farnesene as the major product from farnesyl diphosphate (FPP). Moreover, mRNA expression and leaf volatile analyses indicated that MkTPS1 accounts for (−)-sabinene emitted by M. koenigii leaves. Overall, the transcriptome data generated in this study will be a great resource and the start point for characterizing genes involved in the biosynthetic pathway of medicinally important carbazole alkaloids.
Martin Steinhaus - One of the best experts on this subject based on the ideXlab platform.
-
characterization of the major odor active compounds in the leaves of the Curry Tree bergera koenigii l by aroma extract dilution analysis
Journal of Agricultural and Food Chemistry, 2015Co-Authors: Martin SteinhausAbstract:Curry leaves are a popular seasoning herb with a pronounced sulfury and burnt odor, the molecular background of which was yet unclear. Application of an aroma extract dilution analysis to the volatile fraction of Curry leaves isolated by solvent extraction and solvent-assisted flavor evaporation afforded 23 odor-active compounds with flavor dilution (FD) factors ranging from 1 to 8192. On the basis of the comparison of their retention indices, mass spectra, and odor properties with data of reference compounds, the structures of 22 odorants could be assigned, 15 of which had not been reported in Curry leaves before. Odorants with high FD factors included 1-phenylethanethiol (FD factor 8192), linalool (4096), α-pinene (2048), 1,8-cineole (1024), (3Z)-hex-3-enal (256), 3-(methylsulfanyl)propanal (128), myrcene (64), (3Z)-hex-3-en-1-ol (32), and (2E,6Z)-nona-2,6-dienal (32). The unique sulfury and burnt odor exhibited by 1-phenylethanethiol in combination with its high FD factor suggested that it constitutes the character impact compound of fresh Curry leaf aroma.
