A Novel Defensin Encoded by a Mungbean cDNA Exhibits Insecticidal Activity against Bruchid

Chen, Kuan‐Chung; Lin, Ching Yu; Kuan, Cheng Chun; Sung, Hsien Yi; Chen, Ching San

doi:10.1021/jf020527q

Cited by 92 publications

(81 citation statements)

References 38 publications

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“…Defensin expression in plants can typically be found in leaves (Terras et al, 1995), seeds (Almeida et al, 2000;Chen et al, 2002), flowers (Park et al, 2002;Lay et al, 2003) and can be induced by stress (Koike et al, 2002) or pathogen inoculation (Manners et al, 1998;Berrocal-Lobo et al, 2002). Plant defensins have been identified that confer resistance to fungal (Gao et al, 2000;Park et al, 2002;Cabral et al, 2003), bacterial (Koike et al, 2002), or insect pathogens (Chen et al, 2002;Lay et al, 2003).…”

Section: A Diverse Family Of Cys Cluster Proteins With Similarity To mentioning

confidence: 99%

Computational Identification and Characterization of Novel Genes from Legumes

et al. 2004

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The Fabaceae, the third largest family of plants and the source of many crops, has been the target of many genomic studies. Currently, only the grasses surpass the legumes for the number of publicly available expressed sequence tags (ESTs). The quantity of sequences from diverse plants enables the use of computational approaches to identify novel genes in specific taxa. We used BLAST algorithms to compare unigene sets from Medicago truncatula, Lotus japonicus, and soybean (Glycine max and Glycine soja) to nonlegume unigene sets, to GenBank's nonredundant and EST databases, and to the genomic sequences of rice (Oryza sativa) and Arabidopsis. As a working definition, putatively legume-specific genes had no sequence homology, below a specified threshold, to publicly available sequences of nonlegumes. Using this approach, 2,525 legume-specific EST contigs were identified, of which less than three percent had clear homology to previously characterized legume genes. As a first step toward predicting function, related sequences were clustered to build motifs that could be searched against protein databases. Three families of interest were more deeply characterized: F-box related proteins, Pro-rich proteins, and Cys cluster proteins (CCPs). Of particular interest were the .300 CCPs, primarily from nodules or seeds, with predicted similarity to defensins. Motif searching also identified several previously unknown CCP-like open reading frames in Arabidopsis. Evolutionary analyses of the genomic sequences of several CCPs in M. truncatula suggest that this family has evolved by local duplications and divergent selection.Legumes constitute a large plant family that presents humans with a treasure trove of resources for a variety of uses. Throughout the world, legumes provide important sources of protein, oil, mineral nutrients, and nutritionally important natural products (Graham and Vance, 2003). Grain legume species, including pea (Pisum sativum), common bean (Phaseolus vulgaris), and lentil (Lens culinaris), account for over 33% of human dietary protein. Other legumes, including clovers (Trifolium spp.) and medics (Medicago spp.), are widely used as animal fodder. Refined oils, such as soybean (Glycine max) oil, have industrial applications in paint, diesel fuel, electrical insulation, and solvents. Legumes also accumulate phytochemicals, including isoflavonoids, which impact human health through pharmaceutical use and as dietary supplements (Dixon and Sumner, 2003).An important feature of legumes is their ability to obtain nutrients via symbioses with soil microbes. The formation of nitrogen-fixing nodules via interaction with bacteria collectively know as rhizobia is virtually unique to legumes, although some species in eight families of the eurosid I clade of dicots can form nodules in association with nitrogen-fixing actinomycetes (Soltis et al., 1995;Doyle and Luckow, 2003). An exchange of specific signal molecules between host and microbe triggers many developmental events in the host, including extensive modulation...

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Section: A Diverse Family Of Cys Cluster Proteins With Similarity To mentioning

confidence: 99%

Computational Identification and Characterization of Novel Genes from Legumes

et al. 2004

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“…They have been identified in diverse taxa with many defense roles, including antifungal (Gao et al, 2000;Park et al, 2002;Cabral et al, 2003;Lay et al, 2003a), antibacterial (Osborn et al, 1995;Segura et al, 1998;Koike et al, 2002), anti-insect (Chen et al, 2002;Lay et al, 2003b), and protease inhibitory (Osborn et al, 1995;Wijaya et al, 2000) activities. In many cases, small differences in amino acid sequence can predict the specificity of the defense role (GarciaOlmedo et al, 1998).…”

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confidence: 99%

Genome Organization of More Than 300 Defensin-Like Genes in Arabidopsis

et al. 2005

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Defensins represent an ancient and diverse set of small, cysteine-rich, antimicrobial peptides in mammals, insects, and plants. According to published accounts, most species' genomes contain 15 to 50 defensins. Starting with a set of largely nodulespecific defensin-like sequences (DEFLs) from the model legume Medicago truncatula, we built motif models to search the nearcomplete Arabidopsis (Arabidopsis thaliana) genome. We identified 317 DEFLs, yet 80% were unannotated at The Arabidopsis Information Resource and had no prior evidence of expression. We demonstrate that many of these DEFL genes are clustered in the Arabidopsis genome and that individual clusters have evolved from successive rounds of gene duplication and divergent or purifying selection. Sequencing reverse transcription-PCR products from five DEFL clusters confirmed our gene predictions and verified expression. For four of the largest clusters of DEFLs, we present the first evidence of expression, most frequently in floral tissues. To determine the abundance of DEFLs in other plant families, we used our motif models to search The Institute for Genomic Research's gene indices and identified approximately 1,100 DEFLs. These expressed DEFLs were found mostly in reproductive tissues, consistent with our reverse transcription-PCR results. Sequence-based clustering of all identified DEFLs revealed separate tissue-or taxon-specific subgroups. Previously, we and others showed that more than 300 DEFL genes were expressed in M. truncatula nodules, organs not present in most plants. We have used this information to annotate the Arabidopsis genome and now provide evidence of a large DEFL superfamily present in expressed tissues of all sequenced plants.Organisms are constantly confronted with potentially pathogenic microorganisms. Yet, few encounters result in disease, due to the multilayered lines of defense each organism possesses. In vertebrates, adaptive immunity has long held center stage because of its ability to recognize almost any foreign antigen. The ancient innate immune system is equally important and provides a critical line of defense in vertebrates, invertebrates, plants, and insects (Thomma et al., 2002;Beutler, 2004;Bulet et al., 2004;Finlay and Hancock, 2004).In plants, innate immunity occurs via elaborate mechanisms (Dangl and Jones, 2001;Veronese et al., 2003). The plant cell wall serves as a barrier to microbial penetration. Antimicrobial compounds deter would-be invaders. Should penetration occur, recognition leads to the production of reactive oxygen intermediates, cell wall strengthening, activation of protein kinase pathways, and the production of signaling intermediates. Signaling events lead to localized responses such as a hypersensitive response (programmed cell death) or to the release of antimicrobial compounds. The plant is also immunized against unrelated pathogens via systemic acquired resistance (Delaney, 1997;Dong, 2001;Gozzo, 2003).Much attention has focused on the interaction of plant resistance genes (R-genes) and pathoge...

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“…The deduced nucleotide sequence of the defensin gene showed more than 90% identity to the nucleotide sequence of the well characterized defensins of Vigna radiata . A bacterially expressed mungbean ( Vigna radiata ) defensin have been earlier reported (VrCRP) to have exhibited both antifungal and insecticidal activities [40, 41]. Plant defensin from cowpea have been shown to be efficiently inhibiting α- amylases from bean weevils and Mexican bean weevil [42].…”

Section: Discussionmentioning

confidence: 99%

Bruchid egg induced transcript dynamics in developing seeds of black gram (Vigna mungo)

et al. 2017

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Black gram (Vigna mungo) seeds are a rich source of digestible proteins, however, during storage these seeds are severely damaged by bruchids (Callosobruchus spp.), reducing seed quality and yield losses. Most of the cultivated genotypes of black gram are susceptible to bruchids, however, few tolerant genotypes have also been identified but the mechanism of tolerance is poorly understood. We employed Suppression Subtractive Hybridization (SSH) to identify specifically, but rarely expressed bruchid egg induced genes in black gram. In this study, Suppression Subtractive Hybridization (SSH) library was constructed to study the genes involved in defense response in black gram against bruchid infestation. An EST library of 277 clones was obtained for further analyses. Based on CAP3 assembly, 134 unigenes were computationally annotated using Blast2GOPRO software. In all, 20 defense related genes were subject to quantitative PCR analysis (qPCR) out of which 12 genes showed up-regulation in developing seeds of the pods oviposited by bruchids. Few major defense genes like defensin, pathogenesis related protein (PR), lipoxygenase (LOX) showed high expression levels in the oviposited population when compared with the non-oviposited plants. This is the first report on defense related gene transcript dynamics during the bruchid-black gram interaction using SSH library. This library would be useful to clone defense related gene(s) such as defensin as represented in our library for crop improvement.

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A Novel Defensin Encoded by a Mungbean cDNA Exhibits Insecticidal Activity against Bruchid

Cited by 92 publications

References 38 publications

Computational Identification and Characterization of Novel Genes from Legumes

Computational Identification and Characterization of Novel Genes from Legumes

Genome Organization of More Than 300 Defensin-Like Genes in Arabidopsis

Bruchid egg induced transcript dynamics in developing seeds of black gram (Vigna mungo)

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