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Phenotypic instability and epigenetic variability in a diploid potato of hybrid origin, Solanum ruiz-lealii.

Marfil CF, Camadro EL, Masuelli RW - BMC Plant Biol. (2009)

Bottom Line: AFLP markers and restriction patterns of mitochondrial DNA did not allow the differentiation of normal from abnormal flower phenotypes.However, methylation patterns of nuclear DNA discriminated normal and abnormal flower phenotypes into two different groups, indicating that abnormal phenotypes have a similar methylation status which, in turn, was different from the methylation patterns of normal phenotypes.In addition, the variability detected for DNA methylation was greater than the detected for nucleotide sequence.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratorio de Biología Molecular, EEA La Consulta INTA, Facultad de Ciencias Agrarias, Universidad Nacional de Cuyo and CONICET, Chacras de Coria Mendoza, Argentina.

ABSTRACT

Background: The wild potato Solanum ruiz-lealii Brüch. (2n = 2x = 24), a species of hybrid origin, is endemic to Mendoza province, Argentina. Recurrent flower malformations, which varied among inflorescences of the same plant, were observed in a natural population. These abnormalities could be the result of genomic instabilities, nucleus-cytoplasmic incompatibility or epigenetic changes. To shed some light on their origin, nuclear and mitochondrial DNA of plants with normal and plants with both normal and malformed flowers (from here on designated as plants with normal and plants with abnormal flower phenotypes, respectively) were analyzed by AFLP and restriction analyses, respectively. Also, the wide genome methylation status and the level of methylation of a repetitive sequence were studied by MSAP and Southern blots analyses, respectively.

Results: AFLP markers and restriction patterns of mitochondrial DNA did not allow the differentiation of normal from abnormal flower phenotypes. However, methylation patterns of nuclear DNA discriminated normal and abnormal flower phenotypes into two different groups, indicating that abnormal phenotypes have a similar methylation status which, in turn, was different from the methylation patterns of normal phenotypes. The abnormal flower phenotype was obtained by treating a normal plant with 5-Azacytidine, a demethylating agent, giving support to the idea of the role of DNA methylation in the origin of flower abnormalities. In addition, the variability detected for DNA methylation was greater than the detected for nucleotide sequence.

Conclusion: The epigenetic nature of the observed flower abnormalities is consistent with the results and indicates that in the diploid hybrid studied, natural variation in methylation profiles of anonymous DNA sequences could be of biological significance.

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Related in: MedlinePlus

Flower phenotypes of eight S. ruiz-lealii plants. A, B and C, normal flowers from plants 13.4, V0 and 17.1, respectively. D, E and F, flowers from plant 6. D, intermediate flower phenotype with twisted anthers and normal petals and style. E, twin flower. F, flower with twisted style. G and H, flowers from plant 13.2. G, flower with bilateral symmetry. H, staminoid petals (sepals and style removed). I, flower from plant 19.3 that resembles normal flower, but with dissected petals. J, carpelloid stamens from plant 19.3. K, extreme flower phenotype from plant 19.3, with rudimentary stamens and petals. L, M, N and O, flowers from plant 03. L, normal flower. M, flower with staminoid petals and rudimentary stamens. N, flower with reduced number of stamens, dissected petals and fusion between a stamen and the pistil. O, flower with extra number of petals (dissected) and reduced number of stamens. P, Q and R, flowers from plant 9. P, normal flower. Q, flower with staminoid petals, rudimentary stamens and bifurcated stigma. R, flower with dissected petals and twisted anthers.
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Figure 2: Flower phenotypes of eight S. ruiz-lealii plants. A, B and C, normal flowers from plants 13.4, V0 and 17.1, respectively. D, E and F, flowers from plant 6. D, intermediate flower phenotype with twisted anthers and normal petals and style. E, twin flower. F, flower with twisted style. G and H, flowers from plant 13.2. G, flower with bilateral symmetry. H, staminoid petals (sepals and style removed). I, flower from plant 19.3 that resembles normal flower, but with dissected petals. J, carpelloid stamens from plant 19.3. K, extreme flower phenotype from plant 19.3, with rudimentary stamens and petals. L, M, N and O, flowers from plant 03. L, normal flower. M, flower with staminoid petals and rudimentary stamens. N, flower with reduced number of stamens, dissected petals and fusion between a stamen and the pistil. O, flower with extra number of petals (dissected) and reduced number of stamens. P, Q and R, flowers from plant 9. P, normal flower. Q, flower with staminoid petals, rudimentary stamens and bifurcated stigma. R, flower with dissected petals and twisted anthers.

Mentions: The morphology of the leaves, tubers and stolons was normal in all plants studied, but normal and malformed flowers co-existed in each of five plants (Table 1). Pollen viability of normal flowers ranged from 18 to 80%; on the other hand, malformed flowers in those same plants bore no pollen. In Figure 2, the observed flower phenotypes are presented; the corolla shape of normal plants 13.4, V0 and 17.1 varied from rotate (Figure 2A–B) to stellate (Figure 2C). Flower abnormalities found in different plants included: twisted anthers and style and twin flowers (Figure 2D–F); bilateral symmetry and dissected petals (Figure 2G and 2I); rudimentary stamens and petals (Figure 2K); homeotic changes like staminoid petals (Figure 2H, M and 2Q) and carpelloid stamens (Figure 2J).


Phenotypic instability and epigenetic variability in a diploid potato of hybrid origin, Solanum ruiz-lealii.

Marfil CF, Camadro EL, Masuelli RW - BMC Plant Biol. (2009)

Flower phenotypes of eight S. ruiz-lealii plants. A, B and C, normal flowers from plants 13.4, V0 and 17.1, respectively. D, E and F, flowers from plant 6. D, intermediate flower phenotype with twisted anthers and normal petals and style. E, twin flower. F, flower with twisted style. G and H, flowers from plant 13.2. G, flower with bilateral symmetry. H, staminoid petals (sepals and style removed). I, flower from plant 19.3 that resembles normal flower, but with dissected petals. J, carpelloid stamens from plant 19.3. K, extreme flower phenotype from plant 19.3, with rudimentary stamens and petals. L, M, N and O, flowers from plant 03. L, normal flower. M, flower with staminoid petals and rudimentary stamens. N, flower with reduced number of stamens, dissected petals and fusion between a stamen and the pistil. O, flower with extra number of petals (dissected) and reduced number of stamens. P, Q and R, flowers from plant 9. P, normal flower. Q, flower with staminoid petals, rudimentary stamens and bifurcated stigma. R, flower with dissected petals and twisted anthers.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2656509&req=5

Figure 2: Flower phenotypes of eight S. ruiz-lealii plants. A, B and C, normal flowers from plants 13.4, V0 and 17.1, respectively. D, E and F, flowers from plant 6. D, intermediate flower phenotype with twisted anthers and normal petals and style. E, twin flower. F, flower with twisted style. G and H, flowers from plant 13.2. G, flower with bilateral symmetry. H, staminoid petals (sepals and style removed). I, flower from plant 19.3 that resembles normal flower, but with dissected petals. J, carpelloid stamens from plant 19.3. K, extreme flower phenotype from plant 19.3, with rudimentary stamens and petals. L, M, N and O, flowers from plant 03. L, normal flower. M, flower with staminoid petals and rudimentary stamens. N, flower with reduced number of stamens, dissected petals and fusion between a stamen and the pistil. O, flower with extra number of petals (dissected) and reduced number of stamens. P, Q and R, flowers from plant 9. P, normal flower. Q, flower with staminoid petals, rudimentary stamens and bifurcated stigma. R, flower with dissected petals and twisted anthers.
Mentions: The morphology of the leaves, tubers and stolons was normal in all plants studied, but normal and malformed flowers co-existed in each of five plants (Table 1). Pollen viability of normal flowers ranged from 18 to 80%; on the other hand, malformed flowers in those same plants bore no pollen. In Figure 2, the observed flower phenotypes are presented; the corolla shape of normal plants 13.4, V0 and 17.1 varied from rotate (Figure 2A–B) to stellate (Figure 2C). Flower abnormalities found in different plants included: twisted anthers and style and twin flowers (Figure 2D–F); bilateral symmetry and dissected petals (Figure 2G and 2I); rudimentary stamens and petals (Figure 2K); homeotic changes like staminoid petals (Figure 2H, M and 2Q) and carpelloid stamens (Figure 2J).

Bottom Line: AFLP markers and restriction patterns of mitochondrial DNA did not allow the differentiation of normal from abnormal flower phenotypes.However, methylation patterns of nuclear DNA discriminated normal and abnormal flower phenotypes into two different groups, indicating that abnormal phenotypes have a similar methylation status which, in turn, was different from the methylation patterns of normal phenotypes.In addition, the variability detected for DNA methylation was greater than the detected for nucleotide sequence.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratorio de Biología Molecular, EEA La Consulta INTA, Facultad de Ciencias Agrarias, Universidad Nacional de Cuyo and CONICET, Chacras de Coria Mendoza, Argentina.

ABSTRACT

Background: The wild potato Solanum ruiz-lealii Brüch. (2n = 2x = 24), a species of hybrid origin, is endemic to Mendoza province, Argentina. Recurrent flower malformations, which varied among inflorescences of the same plant, were observed in a natural population. These abnormalities could be the result of genomic instabilities, nucleus-cytoplasmic incompatibility or epigenetic changes. To shed some light on their origin, nuclear and mitochondrial DNA of plants with normal and plants with both normal and malformed flowers (from here on designated as plants with normal and plants with abnormal flower phenotypes, respectively) were analyzed by AFLP and restriction analyses, respectively. Also, the wide genome methylation status and the level of methylation of a repetitive sequence were studied by MSAP and Southern blots analyses, respectively.

Results: AFLP markers and restriction patterns of mitochondrial DNA did not allow the differentiation of normal from abnormal flower phenotypes. However, methylation patterns of nuclear DNA discriminated normal and abnormal flower phenotypes into two different groups, indicating that abnormal phenotypes have a similar methylation status which, in turn, was different from the methylation patterns of normal phenotypes. The abnormal flower phenotype was obtained by treating a normal plant with 5-Azacytidine, a demethylating agent, giving support to the idea of the role of DNA methylation in the origin of flower abnormalities. In addition, the variability detected for DNA methylation was greater than the detected for nucleotide sequence.

Conclusion: The epigenetic nature of the observed flower abnormalities is consistent with the results and indicates that in the diploid hybrid studied, natural variation in methylation profiles of anonymous DNA sequences could be of biological significance.

Show MeSH
Related in: MedlinePlus