Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds
<p>Abstract</p> <p>Background</p> <p>Tocopherols are natural antioxidants with both <it>in vivo</it> (vitamin E) and <it>in vitro</it> activity. Sunflower seeds contain predominantly alpha-tocopherol (>90% of total tocopherols), with maximum v...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2012-05-01
|
| Series: | BMC Plant Biology |
| Online Access: | http://www.biomedcentral.com/1471-2229/12/71 |
| _version_ | 1819035398750339072 |
|---|---|
| author | García-Moreno María J Fernández-Martínez José M Velasco Leonardo Pérez-Vich Begoña |
| author_facet | García-Moreno María J Fernández-Martínez José M Velasco Leonardo Pérez-Vich Begoña |
| author_sort | García-Moreno María J |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Tocopherols are natural antioxidants with both <it>in vivo</it> (vitamin E) and <it>in vitro</it> activity. Sunflower seeds contain predominantly alpha-tocopherol (>90% of total tocopherols), with maximum vitamin E effect but lower <it>in vitro</it> antioxidant action than other tocopherol forms such as gamma-tocopherol. Sunflower germplasm with stable high levels of gamma-tocopherol (>85%) has been developed. The trait is controlled by recessive alleles at a single locus <it>Tph2</it> underlying a gamma-tocopherol methyltransferase (gamma-TMT). Additionally, unstable expression of increased gamma-tocopherol content in the range from 5 to 85% has been reported. The objective of this research was to determine the genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds.</p> <p>Results</p> <p>Male sterile plants of nuclear male sterile line nmsT2100, with stable high gamma-tocopherol content, were crossed with plants of line IAST-1, with stable high gamma-tocopherol content but derived from a population that exhibited unstable expression of the trait. F<sub>2</sub> seeds showed continuous segregation for gamma-tocopherol content from 1.0 to 99.7%. Gamma-tocopherol content in F<sub>2</sub> plants (average of 24 individual F<sub>3</sub> seeds) segregated from 59.4 to 99.4%. A genetic linkage map comprising 17 linkage groups (LGs) was constructed from this population using 109 SSR and 20 INDEL marker loci, including INDEL markers for tocopherol biosynthesis genes. QTL analysis revealed a major QTL on LG 8 that corresponded to the gamma-TMT <it>Tph2</it> locus, which suggested that high gamma-tocopherol lines nmsT2100 and IAST-1 possess different alleles at this locus. Modifying genes were identified at LGs 1, 9, 14 and 16, corresponding in most cases with gamma-TMT duplicated loci.</p> <p>Conclusions</p> <p>Unstable expression of high gamma-tocopherol content is produced by the effect of modifying genes on <it>tph2</it><sup><it>a</it></sup> allele at the gamma-TMT <it>Tph2</it> gene. This allele is present in line IAST-1 and is different to allele <it>tph2</it> present in line nmsT2100, which is not affected by modifying genes. No sequence differences at the gamma-TMT gene were found associated to allelic unstability. Our results suggested that modifying genes are mostly epistatically interacting gamma-TMT duplicated loci.</p> |
| first_indexed | 2024-12-21T07:49:00Z |
| format | Article |
| id | doaj.art-b3f43a9f1862421c9f1adee4b53d05b6 |
| institution | Directory Open Access Journal |
| issn | 1471-2229 |
| language | English |
| last_indexed | 2024-12-21T07:49:00Z |
| publishDate | 2012-05-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Plant Biology |
| spelling | doaj.art-b3f43a9f1862421c9f1adee4b53d05b62022-12-21T19:11:07ZengBMCBMC Plant Biology1471-22292012-05-011217110.1186/1471-2229-12-71Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seedsGarcía-Moreno María JFernández-Martínez José MVelasco LeonardoPérez-Vich Begoña<p>Abstract</p> <p>Background</p> <p>Tocopherols are natural antioxidants with both <it>in vivo</it> (vitamin E) and <it>in vitro</it> activity. Sunflower seeds contain predominantly alpha-tocopherol (>90% of total tocopherols), with maximum vitamin E effect but lower <it>in vitro</it> antioxidant action than other tocopherol forms such as gamma-tocopherol. Sunflower germplasm with stable high levels of gamma-tocopherol (>85%) has been developed. The trait is controlled by recessive alleles at a single locus <it>Tph2</it> underlying a gamma-tocopherol methyltransferase (gamma-TMT). Additionally, unstable expression of increased gamma-tocopherol content in the range from 5 to 85% has been reported. The objective of this research was to determine the genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds.</p> <p>Results</p> <p>Male sterile plants of nuclear male sterile line nmsT2100, with stable high gamma-tocopherol content, were crossed with plants of line IAST-1, with stable high gamma-tocopherol content but derived from a population that exhibited unstable expression of the trait. F<sub>2</sub> seeds showed continuous segregation for gamma-tocopherol content from 1.0 to 99.7%. Gamma-tocopherol content in F<sub>2</sub> plants (average of 24 individual F<sub>3</sub> seeds) segregated from 59.4 to 99.4%. A genetic linkage map comprising 17 linkage groups (LGs) was constructed from this population using 109 SSR and 20 INDEL marker loci, including INDEL markers for tocopherol biosynthesis genes. QTL analysis revealed a major QTL on LG 8 that corresponded to the gamma-TMT <it>Tph2</it> locus, which suggested that high gamma-tocopherol lines nmsT2100 and IAST-1 possess different alleles at this locus. Modifying genes were identified at LGs 1, 9, 14 and 16, corresponding in most cases with gamma-TMT duplicated loci.</p> <p>Conclusions</p> <p>Unstable expression of high gamma-tocopherol content is produced by the effect of modifying genes on <it>tph2</it><sup><it>a</it></sup> allele at the gamma-TMT <it>Tph2</it> gene. This allele is present in line IAST-1 and is different to allele <it>tph2</it> present in line nmsT2100, which is not affected by modifying genes. No sequence differences at the gamma-TMT gene were found associated to allelic unstability. Our results suggested that modifying genes are mostly epistatically interacting gamma-TMT duplicated loci.</p>http://www.biomedcentral.com/1471-2229/12/71 |
| spellingShingle | García-Moreno María J Fernández-Martínez José M Velasco Leonardo Pérez-Vich Begoña Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds BMC Plant Biology |
| title | Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds |
| title_full | Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds |
| title_fullStr | Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds |
| title_full_unstemmed | Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds |
| title_short | Genetic basis of unstable expression of high gamma-tocopherol content in sunflower seeds |
| title_sort | genetic basis of unstable expression of high gamma tocopherol content in sunflower seeds |
| url | http://www.biomedcentral.com/1471-2229/12/71 |
| work_keys_str_mv | AT garciamorenomariaj geneticbasisofunstableexpressionofhighgammatocopherolcontentinsunflowerseeds AT fernandezmartinezjosem geneticbasisofunstableexpressionofhighgammatocopherolcontentinsunflowerseeds AT velascoleonardo geneticbasisofunstableexpressionofhighgammatocopherolcontentinsunflowerseeds AT perezvichbegona geneticbasisofunstableexpressionofhighgammatocopherolcontentinsunflowerseeds |