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Your search keyword '"El-Sayed, Magdi"' showing total 5 results
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5 results on '"El-Sayed, Magdi"'

1. RNA-sequencing-based transcriptome and biochemical analyses of steroidal saponin pathway in a complete set of Allium fistulosum-A. cepa monosomic addition lines.

Author

Abdelrahman M, El-Sayed M, Sato S, Hirakawa H, Ito SI, Tanaka K, Mine Y, Sugiyama N, Suzuki Y, Yamauchi N, and Shigyo M

Subjects
Biological Assay, Biosynthetic Pathways genetics, Gene Expression Profiling, Gene Expression Regulation, Plant, Genes, Plant, Models, Biological, Allium genetics, Saponins biosynthesis, Sequence Analysis, RNA methods, Steroids biosynthesis, Transcriptome genetics
Abstract

The genus Allium is a rich source of steroidal saponins, and its medicinal properties have been attributed to these bioactive compounds. The saponin compounds with diverse structures play a pivotal role in Allium's defense mechanism. Despite numerous studies on the occurrence and chemical structure of steroidal saponins, their biosynthetic pathway in Allium species is poorly understood. The monosomic addition lines (MALs) of the Japanese bunching onion (A. fistulosum, FF) with an extra chromosome from the shallot (A. cepa Aggregatum group, AA) are powerful genetic resources that enable us to understand many physiological traits of Allium. In the present study, we were able to isolate and identify Alliospiroside A saponin compound in A. fistulosum with extra chromosome 2A from shallot (FF2A) and its role in the defense mechanism against Fusarium pathogens. Furthermore, to gain molecular insight into the Allium saponin biosynthesis pathway, high-throughput RNA-Seq of the root, bulb, and leaf of AA, MALs, and FF was carried out using Illumina's HiSeq 2500 platform. An open access Allium Transcript Database (Allium TDB, http://alliumtdb.kazusa.or.jp) was generated based on RNA-Seq data. The resulting assembled transcripts were functionally annotated, revealing 50 unigenes involved in saponin biosynthesis. Differential gene expression (DGE) analyses of AA and MALs as compared with FF (as a control) revealed a strong up-regulation of the saponin downstream pathway, including cytochrome P450, glycosyltransferase, and beta-glucosidase in chromosome 2A. An understanding of the saponin compounds and biosynthesis-related genes would facilitate the development of plants with unique saponin content and, subsequently, improved disease resistance.

Published
2017
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2. Discovery of a new source of resistance to Fusarium oxysporum, cause of Fusarium wilt in Allium fistulosum, located on chromosome 2 of Allium cepa Aggregatum group.

Author

Vu HQ, El-Sayed MA, Ito S, Yamauchi N, and Shigyo M

Subjects
Allium immunology, Allium microbiology, Chromatography, Thin Layer, Disk Diffusion Antimicrobial Tests, Fusarium pathogenicity, Mycelium, Phenols analysis, Phenols isolation & purification, Phenols pharmacology, Plant Diseases microbiology, Plant Extracts chemistry, Plant Extracts isolation & purification, Plant Exudates chemistry, Plant Exudates isolation & purification, Plant Exudates pharmacology, Plant Roots chemistry, Plant Roots genetics, Plant Roots immunology, Plant Roots microbiology, Saponins analysis, Saponins isolation & purification, Saponins pharmacology, Seedlings chemistry, Seedlings genetics, Seedlings immunology, Seedlings microbiology, Seeds chemistry, Seeds genetics, Seeds immunology, Seeds microbiology, Spores, Fungal, Allium chemistry, Allium genetics, Chromosomes, Plant genetics, Fusarium drug effects, Plant Diseases immunology, Plant Extracts pharmacology
Abstract

This study was carried out to evaluate the antifungal effect of Allium cepa Aggregatum group (shallot) metabolites on Fusarium oxysporum and to determine the shallot chromosome(s) related to Fusarium wilt resistance using a complete set of eight Allium fistulosum - shallot monosomic addition lines. The antifungal effects of hexane, butanol, and water extraction fractions from bulbs of shallot on 35 isolates of F. oxysporum were examined using the disc diffusion method. Only hexane and butanol fractions showed high antifungal activity. Shallot showed no symptom of disease after inoculation with F. oxysporum f. sp. cepae. The phenolic content of the roots and the saponin content of root exudates of inoculated shallot increased to much higher levels than those of the control at 3 days after inoculation. Application of freeze-dried shallot root exudates to seeds of A. fistulosum soaked in a spore suspension of F. oxysporum resulted in protection of seedlings against infection. Among eight monosomic addition lines and A. fistulosum, FF+2A showed the highest resistance to Fusarium wilt. This monosomic addition line also showed a specific saponin band derived from shallot on the thin layer chromatography profile of saponins in the eight monosomic addition lines. The chromosome 2A of shallot might possess some of the genes related to Fusarium wilt resistance.

Published
2012
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5. Correction: RNA-sequencing-based transcriptome and biochemical analyses of steroidal saponin pathway in a complete set of Allium fistulosum—A. cepa monosomic addition lines

Author

Abdelrahman, Mostafa, El-Sayed, Magdi, Sato, Shusei, Hirakawa, Hideki, Ito, Shin-ichi, Tanaka, Keisuke, Mine, Yoko, Sugiyama, Nobuo, Suzuki, Yutaka, Yamauchi, Naoki, and Shigyo, Masayoshi

Subjects
Multidisciplinary, Sequence Analysis, RNA, Gene Expression Profiling, lcsh:R, Correction, lcsh:Medicine, Saponins, Genes, Plant, Models, Biological, Allium, Biosynthetic Pathways, Gene Expression Regulation, Plant, Biological Assay, Steroids, lcsh:Q, Transcriptome, lcsh:Science
Abstract

The genus Allium is a rich source of steroidal saponins, and its medicinal properties have been attributed to these bioactive compounds. The saponin compounds with diverse structures play a pivotal role in Allium's defense mechanism. Despite numerous studies on the occurrence and chemical structure of steroidal saponins, their biosynthetic pathway in Allium species is poorly understood. The monosomic addition lines (MALs) of the Japanese bunching onion (A. fistulosum, FF) with an extra chromosome from the shallot (A. cepa Aggregatum group, AA) are powerful genetic resources that enable us to understand many physiological traits of Allium. In the present study, we were able to isolate and identify Alliospiroside A saponin compound in A. fistulosum with extra chromosome 2A from shallot (FF2A) and its role in the defense mechanism against Fusarium pathogens. Furthermore, to gain molecular insight into the Allium saponin biosynthesis pathway, high-throughput RNA-Seq of the root, bulb, and leaf of AA, MALs, and FF was carried out using Illumina's HiSeq 2500 platform. An open access Allium Transcript Database (Allium TDB, http://alliumtdb.kazusa.or.jp) was generated based on RNA-Seq data. The resulting assembled transcripts were functionally annotated, revealing 50 unigenes involved in saponin biosynthesis. Differential gene expression (DGE) analyses of AA and MALs as compared with FF (as a control) revealed a strong up-regulation of the saponin downstream pathway, including cytochrome P450, glycosyltransferase, and beta-glucosidase in chromosome 2A. An understanding of the saponin compounds and biosynthesis-related genes would facilitate the development of plants with unique saponin content and, subsequently, improved disease resistance.

Published
2018

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