Isolation and functional characterization of Lycopene β-cyclase (CYC-B) promoter from Solanum habrochaites
Isolation and functional characterization of Lycopene β-cyclase (CYC-B) promoter from Solanum habrochaites
Abstract Background Carotenoids are a group of C40 isoprenoid molecules that play diverse biological and ecological roles in plants. Tomato is an important vegetable in human diet and provides the vitamin A precursor β-carotene. Genes encoding enzymes involved in carotenoid biosynthetic pathway have been cloned. However, regulation of genes involved in carotenoid biosynthetic pathway and accumulation of specific carotenoid in chromoplasts are not well understood. One of the approaches to understand regulation of carotenoid metabolism is to characterize the promoters of genes encoding proteins involved in carotenoid metabolism. Lycopene β-cyclase is one of the crucial enzymes in carotenoid biosynthesis pathway in plants. Its activity is required for synthesis of both α-and β-carotenes that are further converted into other carotenoids such as lutein, zeaxanthin, etc. This study describes the isolation and characterization of chromoplast-specific Lycopene β-cyclase (CYC-B) promoter from a green fruited S. habrochaites genotype EC520061. Results A 908 bp region upstream to the initiation codon of the Lycopene β-cyclase gene was cloned and identified as full-length promoter. To identify promoter region necessary for regulating developmental expression of the ShCYC-B gene, the full-length promoter and its three different 5' truncated fragments were cloned upstream to the initiation codon of GUS reporter cDNA in binary vectors. These four plant transformation vectors were separately transformed in to Agrobacterium. Agrobacterium-mediated transient and stable expression systems were used to study the GUS expression driven by the full-length promoter and its 5' deletion fragments in tomato. The full-length promoter showed a basal level activity in leaves, and its expression was upregulated > 5-fold in flowers and fruits in transgenic tomato plants. Deletion of -908 to -577 bp 5' to ATG decreases the ShCYC-B promoter strength, while deletion of -908 to -437 bp 5' to ATG led to significant increase in the activity of GUS in the transgenic plants. Promoter deletion analysis led to the identification of a short promoter region (-436 bp to ATG) that exhibited a higher promoter strength but similar developmental expression pattern as compared with the full-length ShCYC-B promoter. Conclusion Functional characterization of the full-length ShCYC-B promoter and its deletion fragments in transient expression system in fruto as well as in stable transgenic tomato revealed that the promoter is developmentally regulated and its expression is upregulated in chromoplast-rich flowers and fruits. Our study identified a short promoter region with functional activity and developmental expression pattern similar to that of the full-length ShCYC-B promoter. This 436 bp promoter region can be used in promoter::reporter fusion molecular genetic screens to identify mutants impaired in CYC-B expression, and thus can be a valuable tool in understanding carotenoid metabolism in tomato. Moreover, this short promoter region of ShCYC-B may be useful in genetic engineering of carotenoid content and other agronomic traits in tomato fruits.
Genetic Vectors, Molecular Sequence Data, Plant Science, Solanum, Transformation, Genetic, Solanum lycopersicum, Gene Expression Regulation, Plant, Genes, Reporter, Fluorometry, Cloning, Molecular, Intramolecular Lyases, Promoter Regions, Genetic, Enzyme Assays, Glucuronidase, Sequence Deletion, Base Sequence, Gene Expression Profiling, Botany, Blotting, Northern, Plants, Genetically Modified, Immunohistochemistry, QK1-989, Fruit, Research Article
Genetic Vectors, Molecular Sequence Data, Plant Science, Solanum, Transformation, Genetic, Solanum lycopersicum, Gene Expression Regulation, Plant, Genes, Reporter, Fluorometry, Cloning, Molecular, Intramolecular Lyases, Promoter Regions, Genetic, Enzyme Assays, Glucuronidase, Sequence Deletion, Base Sequence, Gene Expression Profiling, Botany, Blotting, Northern, Plants, Genetically Modified, Immunohistochemistry, QK1-989, Fruit, Research Article
12 Research products, page 1 of 2
- 2016IsAmongTopNSimilarDocuments
- 2003IsAmongTopNSimilarDocuments
- 2022IsAmongTopNSimilarDocuments
- 2014IsAmongTopNSimilarDocuments
- 1998IsAmongTopNSimilarDocuments
- 2012IsAmongTopNSimilarDocuments
- 2001IsAmongTopNSimilarDocuments
chevron_left - 1
- 2
chevron_right
citations This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).48 popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.Top 10% influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).Top 10% impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.Top 10%
