A methylation status analysis of the apomixis-specific region in Paspalum spp. suggests an epigenetic control of parthenogenesis

MARICEL PODIO; MARÍA E. CÁCERES; SERGIO S. SAMOLUK; JOSÉ G. SEIJO; SILVINA C. PESSINO; JUAN PABLO A. ORTÍZ; FULVIO PUPILLI

JOURNAL OF EXPERIMENTAL BOTANY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2014 p. 1 - 14

0022-0957

Apomixis, a clonal plant reproduction by seeds, is controlled in Paspalum spp. by a single and recombinally-blocked locus. Partial sequence analysis of the apomixis locus revealed structural features of heterochromatin: i.e. presence of repetitive elements, gene degeneration and de-regulation. To test the epigenetic control of apomixis, a study on the distribution of cytosine methylation at the apomixis locus and the effect of artificial DNA de-methylation on the mode of reproduction was undertaken in two apomictic Paspalum species. The 5-Methyl cytosine distribution in the apomixis-controlling genomic region was studied in P. simplex by methylation-sensitive RFLP analysis and in P. notatum by FISH. The effect of DNA de-methylation was studied on the mode of reproduction of P. simplex by progeny test analysis of apomictic plants treated with the demethylating agent 5?-Azacytidine. High level of cytosine methylation was detected at the apomixis-controlling genomic region in both species. By analysing a total of 374 open pollination progenies we found that artificial de-methylation had little or no effect on apospory, whereas it induced a significant depression of parthenogenesis. Our results suggested that factors controlling repression of parthenogenesis might be inactivated in apomictic Paspalum by DNA methylation.