1
|
Transposable Elements in the Revealing of Polymorphism-Based Differences in the Seeds of Flax Varieties Grown in Remediated Chernobyl Area. PLANTS 2022; 11:plants11192567. [PMID: 36235434 PMCID: PMC9571286 DOI: 10.3390/plants11192567] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022]
Abstract
The nuclear reactor accident in Chernobyl, Ukraine, resulted in effects both locally and farther away. Most of the contaminated areas were the agricultural fields and forests. Experimental fields were established near Chernobyl—radioactively contaminated fields localized 5 km from Chernobyl Nuclear Power Plant as well as the remediated soil that is localized directly in the Chernobyl town. Two flax varieties growing under chronic exposition to ionizing radiation were used for this study—the local Ukrainian variety Kyivskyi and a commercial variety Bethune. The screening of the length polymorphism generated by transposable elements insertions were performed. All known types of common flax transposon, retrotransposons and iPBS approach were used. In the iPBS multiplex analyze, for the Kyivskyi variety, a unique addition was found in the seeds from the radioactive contaminated field and for the Bethune variety, a total of five amplicon additions were obtained and one deletion. For the TRIM Cassandra fingerprints, two amplicon additions were generated in the seeds from radioactive contaminated fields for the Bethune variety. In summary, the obtained data represent the genetic diversity between control and irradiated subgroups of flax seeds from Chernobyl area and the presence of activated transposable elements due to the irradiation stress.
Collapse
|
2
|
Zhou X, Shafique K, Sajid M, Ali Q, Khalili E, Javed MA, Haider MS, Zhou G, Zhu G. Era-like GTP protein gene expression in rice. BRAZ J BIOL 2021; 82:e250700. [PMID: 34259718 DOI: 10.1590/1519-6984.250700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/19/2021] [Indexed: 11/22/2022] Open
Abstract
The mutations are genetic changes in the genome sequences and have a significant role in biotechnology, genetics, and molecular biology even to find out the genome sequences of a cell DNA along with the viral RNA sequencing. The mutations are the alterations in DNA that may be natural or spontaneous and induced due to biochemical reactions or radiations which damage cell DNA. There is another cause of mutations which is known as transposons or jumping genes which can change their position in the genome during meiosis or DNA replication. The transposable elements can induce by self in the genome due to cellular and molecular mechanisms including hypermutation which caused the localization of transposable elements to move within the genome. The use of induced mutations for studying the mutagenesis in crop plants is very common as well as a promising method for screening crop plants with new and enhanced traits for the improvement of yield and production. The utilization of insertional mutations through transposons or jumping genes usually generates stable mutant alleles which are mostly tagged for the presence or absence of jumping genes or transposable elements. The transposable elements may be used for the identification of mutated genes in crop plants and even for the stable insertion of transposable elements in mutated crop plants. The guanine nucleotide-binding (GTP) proteins have an important role in inducing tolerance in rice plants to combat abiotic stress conditions.
Collapse
Affiliation(s)
- X Zhou
- Linyi University, College of Life Science, Linyi, Shandong, China
| | - K Shafique
- Government Sadiq College Women University, Department of Botany, Bahawalpur, Pakistan
| | - M Sajid
- University of Okara, Faculty of Life Sciences, Department of Biotechnology, Okara, Pakistan
| | - Q Ali
- University of Lahore, Institute of Molecular Biology and Biotechnology, Lahore, Pakistan
| | - E Khalili
- Tarbiat Modarres University, Faculty of Science, Department of Plant Science, Tehran, Iran
| | - M A Javed
- University of the Punjab Lahore, Department of Plant Breeding and Genetics, Lahore, Pakistan
| | - M S Haider
- University of the Punjab Lahore, Department of Plant Pathology, Lahore, Pakistan
| | - G Zhou
- Yangzhou University, The Ministry of Education of China, Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou, Jiangsu, China
| | - G Zhu
- Yangzhou University, The Ministry of Education of China, Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou, Jiangsu, China
| |
Collapse
|
3
|
Negi P, Rai AN, Suprasanna P. Moving through the Stressed Genome: Emerging Regulatory Roles for Transposons in Plant Stress Response. FRONTIERS IN PLANT SCIENCE 2016; 7:1448. [PMID: 27777577 PMCID: PMC5056178 DOI: 10.3389/fpls.2016.01448] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 09/12/2016] [Indexed: 05/02/2023]
Abstract
The recognition of a positive correlation between organism genome size with its transposable element (TE) content, represents a key discovery of the field of genome biology. Considerable evidence accumulated since then suggests the involvement of TEs in genome structure, evolution and function. The global genome reorganization brought about by transposon activity might play an adaptive/regulatory role in the host response to environmental challenges, reminiscent of McClintock's original 'Controlling Element' hypothesis. This regulatory aspect of TEs is also garnering support in light of the recent evidences, which project TEs as "distributed genomic control modules." According to this view, TEs are capable of actively reprogramming host genes circuits and ultimately fine-tuning the host response to specific environmental stimuli. Moreover, the stress-induced changes in epigenetic status of TE activity may allow TEs to propagate their stress responsive elements to host genes; the resulting genome fluidity can permit phenotypic plasticity and adaptation to stress. Given their predominating presence in the plant genomes, nested organization in the genic regions and potential regulatory role in stress response, TEs hold unexplored potential for crop improvement programs. This review intends to present the current information about the roles played by TEs in plant genome organization, evolution, and function and highlight the regulatory mechanisms in plant stress responses. We will also briefly discuss the connection between TE activity, host epigenetic response and phenotypic plasticity as a critical link for traversing the translational bridge from a purely basic study of TEs, to the applied field of stress adaptation and crop improvement.
Collapse
Affiliation(s)
| | | | - Penna Suprasanna
- Plant Stress Physiology and Biotechnology Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research CentreTrombay, India
| |
Collapse
|
4
|
Ratnaparkhe MB, Wang X, Li J, Compton RO, Rainville LK, Lemke C, Kim C, Tang H, Paterson AH. Comparative analysis of peanut NBS-LRR gene clusters suggests evolutionary innovation among duplicated domains and erosion of gene microsynteny. THE NEW PHYTOLOGIST 2011; 192:164-178. [PMID: 21707619 DOI: 10.1111/j.1469-8137.2011.03800.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
• Plant genomes contain numerous disease resistance genes (R genes) that play roles in defense against pathogens. Scarcity of genetic polymorphism makes peanut (Arachis hypogaea) especially vulnerable to a wide variety of pathogens. • Here, we isolated and characterized peanut bacterial artificial chromosomes (BACs) containing a high density of R genes. Analysis of two genomic regions identified several TIR-NBS-LRR (Toll-interleukin-1 receptor, nucleotide-binding site, leucine-rich repeat) resistance gene analogs or gene fragments. We reconstructed their evolutionary history characterized by tandem duplications, possibly facilitated by transposon activities. We found evidence of both intergenic and intragenic gene conversions and unequal crossing-over, which may be driving forces underlying the functional evolution of resistance. • Analysis of the sequence mutations, protein secondary structure and three-dimensional structures, all suggest that LRR domains are the primary contributor to the evolution of resistance genes. The central part of LRR regions, assumed to serve as the active core, may play a key role in the resistance function by having higher rates of duplication and DNA conversion than neighboring regions. The assumed active core is characterized by significantly enriched leucine residue composition, accumulation of positively selected sites, and shorter beta sheets. • Homologous resistance gene analog (RGA)-containing regions in peanut, soybean, Medicago, Arabidopsis and grape have only limited gene synteny and microcollinearity.
Collapse
Affiliation(s)
| | - Xiyin Wang
- Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
- Center for Genomics and Computational Biology, School of Life Sciences, School of Sciences, Hebei United University, Tangshan, Hebei 063000, China
| | - Jingping Li
- Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
| | - Rosana O Compton
- Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
| | - Lisa K Rainville
- Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
| | - Cornelia Lemke
- Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
| | - Changsoo Kim
- Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
| | - Haibao Tang
- Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
| | - Andrew H Paterson
- Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
5
|
Smýkal P, Bačová-Kerteszová N, Kalendar R, Corander J, Schulman AH, Pavelek M. Genetic diversity of cultivated flax (Linum usitatissimum L.) germplasm assessed by retrotransposon-based markers. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2011; 122:1385-97. [PMID: 21293839 DOI: 10.1007/s00122-011-1539-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 01/14/2011] [Indexed: 05/09/2023]
Abstract
Retrotransposon segments were characterized and inter-retrotransposon amplified polymorphism (IRAP) markers developed for cultivated flax (Linum usitatissimum L.) and the Linum genus. Over 75 distinct long terminal repeat retrotransposon segments were cloned, the first set for Linum, and specific primers designed for them. IRAP was then used to evaluate genetic diversity among 708 accessions of cultivated flax comprising 143 landraces, 387 varieties, and 178 breeding lines. These included both traditional and modern, oil (86), fiber (351), and combined-use (271) accessions, originating from 36 countries, and 10 wild Linum species. The set of 10 most polymorphic primers yielded 141 reproducible informative data points per accession, with 52% polymorphism and a 0.34 Shannon diversity index. The maximal genetic diversity was detected among wild Linum species (100% IRAP polymorphism and 0.57 Jaccard similarity), while diversity within cultivated germplasm decreased from landraces (58%, 0.63) to breeding lines (48%, 0.85) and cultivars (50%, 0.81). Application of Bayesian methods for clustering resulted in the robust identification of 20 clusters of accessions, which were unstratified according to origin or user type. This indicates an overlap in genetic diversity despite disruptive selection for fiber versus oil types. Nevertheless, eight clusters contained high proportions (70-100%) of commercial cultivars, whereas two clusters were rich (60%) in landraces. These findings provide a basis for better flax germplasm management, core collection establishment, and exploration of diversity in breeding, as well as for exploration of the role of retrotransposons in flax genome dynamics.
Collapse
Affiliation(s)
- P Smýkal
- Plant Biotechnology Department, Agritec Plant Research Ltd, Šumperk, Czech Republic.
| | | | | | | | | | | |
Collapse
|
6
|
Abstract
In eukaryotic genomes, gene expression and DNA recombination are affected by structural chromatin traits. Chromatin structure is shaped by the activity of enzymes that either introduce covalent modifications in DNA and histone proteins or use energy from ATP to disrupt histone-DNA interactions. The genomic 'marks' that are generated by covalent modifications of histones and DNA, or by the deposition of histone variants, are susceptible to being altered in response to stress. Recent evidence has suggested that proteins generating these epigenetic marks play crucial roles in the defence against pathogens. Histone deacetylases are involved in the activation of jasmonic acid- and ethylene-sensitive defence mechanisms. ATP-dependent chromatin remodellers mediate the constitutive repression of the salicylic acid-dependent pathway, whereas histone methylation at the WRKY70 gene promoter affects the activation of this pathway. Interestingly, bacterial-infected tissues show a net reduction in DNA methylation, which may affect the disease resistance genes responsible for the surveillance against pathogens. As some epigenetic marks can be erased or maintained and transmitted to offspring, epigenetic mechanisms may provide plasticity for the dynamic control of emerging pathogens without the generation of genomic lesions.
Collapse
Affiliation(s)
- María E Alvarez
- CIQUIBIC-CONICET, Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina.
| | | | | |
Collapse
|
7
|
Hayashi K, Yoshida H. Refunctionalization of the ancient rice blast disease resistance gene Pit by the recruitment of a retrotransposon as a promoter. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:413-25. [PMID: 18808453 DOI: 10.1111/j.1365-313x.2008.03694.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The plant genome contains a large number of disease resistance (R) genes that have evolved through diverse mechanisms. Here, we report that a long terminal repeat (LTR) retrotransposon contributed to the evolution of the rice blast resistance gene Pit. Pit confers race-specific resistance against the fungal pathogen Magnaporthe grisea, and is a member of the nucleotide-binding site leucine-rich repeat (NBS-LRR) family of R genes. Compared with the non-functional allele Pit(Npb), the functional allele Pit(K59) contains four amino acid substitutions, and has the LTR retrotransposon Renovator inserted upstream. Pathogenesis assays using chimeric constructs carrying the various regions of Pit(K59) and Pit(Npb) suggest that amino acid substitutions might have a potential effect in Pit resistance; more importantly, the upregulated promoter activity conferred by the Renovator sequence is essential for Pit function. Our data suggest that transposon-mediated transcriptional activation may play an important role in the refunctionalization of additional 'sleeping' R genes in the plant genome.
Collapse
Affiliation(s)
- Keiko Hayashi
- National Agricultural Research Center, National Agriculture and Food Research Organization, 1-2-1 Inada, Jo-etsu, Niigata 943 0193, Japan
| | | |
Collapse
|
8
|
Diversity of LTR-retrotransposons and Enhancer/Suppressor Mutator-like transposons in cassava (Manihot esculenta Crantz). Mol Genet Genomics 2008; 280:305-17. [DOI: 10.1007/s00438-008-0366-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Accepted: 07/02/2008] [Indexed: 11/28/2022]
|
9
|
Schmidt SA, Williams SJ, Wang CIA, Sornaraj P, James B, Kobe B, Dodds PN, Ellis JG, Anderson PA. Purification of the M flax-rust resistance protein expressed in Pichia pastoris. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 50:1107-17. [PMID: 17461785 DOI: 10.1111/j.1365-313x.2007.03104.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The M flax-rust resistance (R) gene is predicted to encode a 150-kDa protein of the Toll-interleukin-like receptor-nucleotide binding site-leucine rich repeat (TIR-NBS-LRR) class of plant disease resistance proteins and provides resistance against the Melampsora lini (flax rust) fungus carrying the AvrM avirulence gene. The extremely low level of this class of R proteins found in plant tissue has precluded their biochemical and structural analysis, and the study of these proteins has been largely restricted to genetic analyses and in vivo investigations. Here we report the production and purification of the M protein in the methalotrophic yeast, Pichia pastoris. Expression trials with five different constructs reveals optimum levels of soluble native M protein can be obtained as an N-terminally 9x His-tagged protein, in which the first 21 amino acids of the predicted wild-type protein are deleted. Expression was achieved using a high cell density fed-batch bioreactor culture at low temperature. M protein was purified to near homogeneity from whole-cell lysates using cation exchange, immobilised metal ion affinity chromatography and gel filtration with a final yield of approximately 3 mg of protein/1000 g wet weight of yeast cells lysed. The successful expression and purification of soluble M protein opens the way for biochemical and structural analysis of this class of important plant proteins.
Collapse
Affiliation(s)
- Simon A Schmidt
- The School of Biological Sciences, Flinders University, G.P.O. Box 2100, Adelaide 5001, Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Proels RK, Roitsch T. Cloning of a CACTA transposon-like insertion in intron I of tomato invertase Lin5 gene and identification of transposase-like sequences of Solanaceae species. JOURNAL OF PLANT PHYSIOLOGY 2006; 163:562-9. [PMID: 16473661 DOI: 10.1016/j.jplph.2005.03.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2004] [Accepted: 03/31/2005] [Indexed: 05/06/2023]
Abstract
Very few CACTA transposon-like sequences have been described in Solanaceae species. Sequence information has been restricted to partial transposase (TPase)-like fragments, and no target gene of CACTA-like transposon insertion has been described in tomato to date. In this manuscript, we report on a CACTA transposon-like insertion in intron I of tomato (Lycopersicon esculentum) invertase gene Lin5 and TPase-like sequences of several Solanaceae species. Consensus primers deduced from the TPase region of the tomato CACTA transposon-like element allowed the amplification of similar sequences from various Solanaceae species of different subfamilies including Solaneae (Solanum tuberosum), Cestreae (Nicotiana tabacum) and Datureae (Datura stramonium). This demonstrates the ubiquitous presence of CACTA-like elements in Solanaceae genomes. The obtained partial sequences are highly conserved, and allow further detection and detailed analysis of CACTA-like transposons throughout Solanaceae species. CACTA-like transposon sequences make possible the evaluation of their use for genome analysis, functional studies of genes and the evolutionary relationships between plant species.
Collapse
Affiliation(s)
- Reinhard K Proels
- Lehrstuhl für Pharmazeutische Biologie, Julius von Sachs Institut, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | | |
Collapse
|
11
|
Chen Y, Schneeberger RG, Cullis CA. A site-specific insertion sequence in flax genotrophs induced by environment. THE NEW PHYTOLOGIST 2005; 167:171-80. [PMID: 15948840 DOI: 10.1111/j.1469-8137.2005.01398.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A single-copy 5.7 kilobase (kb) DNA fragment, termed Linum Insertion Sequence 1 (LIS-1), has been identified and characterized. This is one of the DNA changes associated with the environmentally induced heritable changes resulting in stable lines termed genotrophs in flax (Linum usitatissimum). The insertion sequence and its insertion site have been cloned from genomic libraries and sequenced. PCR products across the insertion and surrounding regions have also been cloned and sequenced. The 5.7 kb DNA fragment is inserted into a 3.7 kb EcoRI fragment in the plastic line (Pl) with the generation of a 3 base pair duplication at the insertion site, as well as additional sequence changes. The identical insertion was also found in other genotrophs and flax varieties. The intact element was not present in Pl but appeared to be generated by a reproducible series of complex rearrangements or insertion events. LIS-1 is the result of a targeted, highly specific, complex insertion event that occurs during the formation of some of the genotrophs, and occurs naturally in many flax and linseed varieties.
Collapse
Affiliation(s)
- Yiming Chen
- Department of Biology, Case Western Reserve University, Cleveland, Ohio 44106-7080, USA
| | | | | |
Collapse
|
12
|
Wulff BBH, Thomas CM, Parniske M, Jones JDG. Genetic variation at the tomato Cf-4/Cf-9 locus induced by EMS mutagenesis and intralocus recombination. Genetics 2005; 167:459-70. [PMID: 15166169 PMCID: PMC1470844 DOI: 10.1534/genetics.167.1.459] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The interaction between tomato (Lycopersicon esculentum) and the leaf mold pathogen Cladosporium fulvum is an excellent model for investigating disease resistance gene evolution. The interaction is controlled in a gene-for-gene manner by Cf genes that encode type I transmembrane extracellular leucine-rich repeat glycoproteins that recognize their cognate fungal avirulence (Avr) proteins. Cf-4 from L. hirsutum and Cf-9 from L. pimpinellifolium are located at the same locus on the short arm of tomato chromosome 1 in an array of five paralogs. Molecular analysis has shown that one mechanism for generating sequence variation in Cf genes is intragenic sequence exchange through unequal crossing over or gene conversion. To investigate this we used a facile genetic selection to identify novel haplotypes in the progeny of Cf-4/Cf-9 trans-heterozygotes that lacked Cf-4 and Cf-9. This selection is based on the ability of Avr4 and Avr9 to induce Cf-4- or Cf-9-dependent seedling death. The crossovers were localized to the same intergenic region defining a recombination hotspot in this cross. As part of a structure-function analysis of Cf-9 and Cf-4, nine EMS-induced mutant alleles have been characterized. Most mutations result in single-amino-acid substitutions in their C terminus at residues that are conserved in other Cf proteins.
Collapse
Affiliation(s)
- Brande B H Wulff
- Sainsbury Laboratory, John Innes Centre, Norwich, NR4 7UH, United Kingdom
| | | | | | | |
Collapse
|
13
|
Staginnus C, Huettel B, Desel C, Schmidt T, Kahl G. A PCR-based assay to detect En/Spm-like transposon sequences in plants. Chromosome Res 2002; 9:591-605. [PMID: 11721956 DOI: 10.1023/a:1012455520353] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Degenerate primers deduced from the TPase region of plant En/Spm-like transposons allowed the amplification of similar sequences from various plant species including sugar beet, wheat and pea. These primers are efficient tools for the detection of this family of transposons in many plant genomes irrespective of sequence knowledge or phenotypic pecularities. An efficient PCR assay was therefore developed for these class II transposons, similar to assays already available for Ty1-copia-, Ty3-gypsy- or LINEs. This approach allowed us not only to show the widespread almost-ubiquitous presence of En/Spm-elements in plant genomes, but also to characterize their genomic organization and chromosomal distribution in the genome of chickpea (Cicer arietinum L.) and its abundance in related Cicer species. This approach can be used for the detection and characterization of endogenous DNA transposable elements in plant species, their complete isolation and evaluation of their use for genome analysis.
Collapse
Affiliation(s)
- C Staginnus
- Plant Molecular Biology, Biocenter, Johann Wolfgang Goethe-University, Frankfurt, Germany
| | | | | | | | | |
Collapse
|
14
|
Fourmann M, Chariot F, Froger N, Delourme R, Brunel D. Expression, mapping, and genetic variability of Brassica napus disease resistance gene analogues. Genome 2001; 44:1083-99. [PMID: 11768212 DOI: 10.1139/g01-098] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Numerous sequences analogous to resistance (R) genes exist in plant genomes and could be involved in resistance traits. The aim of this study was to identify a large number of Brassica napus sequences related to R genes and also to test the adequacy of specific PCR-based tools for studying them. Different consensus primers were compared for their efficiency in amplifying resistance-gene analogues (RGAs) related to the nucleotide-binding-site subgroup of R genes. Specific primers were subsequently designed to fine-study the different RGAs and we tested their efficiency in three species related to B. napus: Brassica oleracea, Brassica rapa, and Arabidopsis thaliana. Forty-four B. napus RGAs were identified. Among 29 examined, at least one-third were expressed. Eighteen RGAs were mapped on 10 of the 19 B. napus linkage groups. The high variability within these sequences permitted discrimination of each genotype within a B. napus collection. The RGA-specific primers amplified RGAs in the B. oleracea and B. rapa genomes, but the sequences appear to be poorly conserved in A. thaliana. Specific RGA primers are a precise tool for studying known-sequence RGAs. These sequences represent interesting markers that could be correlated with resistance traits in B. napus or related Brassica genomes.
Collapse
Affiliation(s)
- M Fourmann
- Station de Génétique et Amelioration des Plantes, Institut National de la Recherche Agronomique, Versailles, France.
| | | | | | | | | |
Collapse
|
15
|
De Lorenzo G, D'Ovidio R, Cervone F. The role of polygalacturonase-inhibiting proteins (PGIPs) in defense against pathogenic fungi. ANNUAL REVIEW OF PHYTOPATHOLOGY 2001; 39:313-35. [PMID: 11701868 DOI: 10.1146/annurev.phyto.39.1.313] [Citation(s) in RCA: 224] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Polygalacturonase-inhibiting proteins (PGIPs) are extracellular plant proteins capable of inhibiting fungal endopolygalacturonases (PGs). Plants have evolved different PGIPs with specific recognition abilities against the many PGs produced by fungi. The genes encoding PGIPs are organized into families, and different members of each family may encode proteins with nearly identical characteristics but different specificities and regulation. PGIPs are typically induced by pathogen infection and stress-related signals. The recognition ability of PGIPs resides in their LRR (leucine-rich repeat) structure, where solvent-exposed residues in the beta-strand/beta-turn motifs of the LRRs are determinants of specificity. Manipulation of the primary structure of PGIPs is expected to generate more efficient PGIPs with novel recognition specificities to protect crop plants against pathogens.
Collapse
Affiliation(s)
- G De Lorenzo
- Dipartimento di Biologia Vegetale, Università di Roma La Sapienza, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | | | | |
Collapse
|
16
|
Tu Z. Molecular and evolutionary analysis of two divergent subfamilies of a novel miniature inverted repeat transposable element in the yellow fever mosquito, Aedes aegypti. Mol Biol Evol 2000; 17:1313-25. [PMID: 10958848 DOI: 10.1093/oxfordjournals.molbev.a026415] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A novel family of miniature inverted repeat transposable elements (MITEs) named Pony was discovered in the yellow fever mosquito, Aedes aegypti. It has all the characteristics of MITEs, including terminal inverted repeats, no coding potential, A+T richness, small size, and the potential to form stable secondary structures. Past mobility of PONY: was indicated by the identification of two Pony insertions which resulted in the duplication of the TA dinucleotide targets. Two highly divergent subfamilies, A and B, were identified in A. aegypti based on sequence comparison and phylogenetic analysis of 38 elements. These subfamilies showed less than 62% sequence similarity. However, within each subfamily, most elements were highly conserved, and multiple subgroups could be identified, indicating recent amplifications from different source genes. Different scenarios are presented to explain the evolutionary history of these subfamilies. Both subfamilies share conserved terminal inverted repeats similar to those of the Tc2 DNA transposons in Caenorhabditis elegans, indicating that Pony may have been borrowing the transposition machinery from a Tc2-like transposon in mosquitoes. In addition to the terminal inverted repeats, full-length and partial subterminal repeats of a sequence motif TTGATTCAWATTCCGRACA represent the majority of the conservation between the two subfamilies, indicating that they may be important structural and/or functional components of the Pony elements. In contrast to known autonomous DNA transposons, both subfamilies of PONY: are highly reiterated in the A. aegypti genome (8,400 and 9, 900 copies, respectively). Together, they constitute approximately 1. 1% of the entire genome. Pony elements were frequently found near other transposable elements or in the noncoding regions of genes. The relative abundance of MITEs varies in eukaryotic genomes, which may have in part contributed to the different organizations of the genomes and reflect different types of interactions between the hosts and these widespread transposable elements.
Collapse
Affiliation(s)
- Z Tu
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.
| |
Collapse
|
17
|
Santagata S, Besmer E, Villa A, Bozzi F, Allingham JS, Sobacchi C, Haniford DB, Vezzoni P, Nussenzweig MC, Pan ZQ, Cortes P. The RAG1/RAG2 complex constitutes a 3' flap endonuclease: implications for junctional diversity in V(D)J and transpositional recombination. Mol Cell 1999; 4:935-47. [PMID: 10635319 DOI: 10.1016/s1097-2765(00)80223-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
During V(D)J recombination, processing of branched coding end intermediates is essential for generating junctional diversity. Here, we report that the RAG1/ RAG2 recombinase is a 3' flap endonuclease. Substrates of this nuclease activity include various coding end intermediates, suggesting a direct role for RAG1/ RAG2 in generating junctional diversity during V(D)J recombination. Evidence is also provided indicating that site-specific RSS nicking involves RAG1/RAG2-mediated processing of a localized flap-like structure, implying 3' flap nicking in multiple DNA processing reactions. We have also demonstrated that the bacterial transposase Tn10 contains a 3' flap endonuclease activity, suggesting a mechanistic parallel between RAG1/RAG2 and other transposases. Based on these data, we propose that numerous transposases may facilitate genomic evolution by removing single-stranded extensions during the processing of excision site junctions.
Collapse
Affiliation(s)
- S Santagata
- Ruttenberg Cancer Center, Mount Sinai School of Medicine, New York, New York 10029, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Henk AD, Warren RF, Innes RW. A new Ac-like transposon of Arabidopsis is associated with a deletion of the RPS5 disease resistance gene. Genetics 1999; 151:1581-9. [PMID: 10101179 PMCID: PMC1460570 DOI: 10.1093/genetics/151.4.1581] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The RPS5 and RFL1 disease resistance genes of Arabidopsis ecotype Col-0 are oriented in tandem and are separated by 1.4 kb. The Ler-0 ecotype contains RFL1, but lacks RPS5. Sequence analysis of the RPS5 deletion region in Ler-0 revealed the presence of an Ac-like transposable element, which we have designated Tag2. Southern hybridization analysis of six Arabidopsis ecotypes revealed 4-11 Tag2-homologous sequences in each, indicating that this element is ubiquitous in Arabidopsis and has been active in recent evolutionary time. The Tag2 insertion adjacent to RFL1 was unique to the Ler-0 ecotype, however, and was not present in two other ecotypes that lack RPS5. DNA sequence from the latter ecotypes lacked a transposon footprint, suggesting that insertion of Tag2 occurred after the initial deletion of RPS5. The deletion breakpoint contained a 192-bp insertion that displayed hallmarks of a nonhomologous DNA end-joining event. We conclude that loss of RPS5 was caused by a double-strand break and subsequent repair, and cannot be attributed to unequal crossing over between resistance gene homologs.
Collapse
Affiliation(s)
- A D Henk
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
| | | | | |
Collapse
|