INVESTIGADORES
SELVA juan pablo
congresos y reuniones científicas
Título:
Expression of genes related with the rna-directed dna methylation (rddm) pathway in eragrostis curvula sexual and apomictic genotypes
Autor/es:
JUAN PABLO SELVA; INGRID GARBUS; JOSE ROMERO; SILVINA PESSINO; OLIVIER LEBLANC; VIVIANA ECHENIQUE
Lugar:
Bahía Blanca
Reunión:
Seminario; IV Ciclo de Seminarios sobre avances en la caracterización genética y molecular de la apomixis; 2014
Institución organizadora:
Departamento de Agronomía (Universidad Nacional del Sur) y CERZOS (CONICET)
Resumen:
Apomixis in plants refers to a diverse group ofdevelopmental behaviors resulting in asexual reproduction through seeds. Apomictic individuals bypass both meiotic reduction and egg cell fertilization to produce offspring that are exact genetic replicas ofthe maternal plant. Given the established relationships between sexual and apomictic pathways, different models have been proposed to explain the occurrence of apomixis at the molecular level involving genetic and epigenetic mechanisms. Weeping lovegrass [Eragrostis curvula (Schrader) Nees] is an apomictic perennial grass native ofSouthern Africa. The type ofapomixis present in the E. curvula is pseudogamous diplospory. There are recent evidences on the role played by certain proteins of the RdDM pathways involved in gametophytic apomixis expression, suggesting an epigenetic regulation ofthe trait. It was reported in maize that loss-of-function of the dmt103 and dmt102 methyltransferases genes partially mimics apomictic developments. Similarly, loss-of-function in ago104, a maize homolog ofago9, also results in apomixis-like traits, giving rise to up to 70% offunctional unreduced female gametes. These data suggest that an epigenetic regulation plays a role on the establishment of apomixis. In this work we studied the expression of EcDmt102-like and EcAgo104-like genes associated to the RdDM pathway in flowers and leaves ofsexual and apomictic E. curvula plants. Using RNA seq data was possible to obtain the complete cDNA sequence for both genes from both apomictic and sexual genotypes. The phylogenetic analysis indicated that these genes group together in the same clade with the corresponding ones of Arabidopsis and Zea mays. The EcDmt102-like and EcAgo104-like genes profiles were analyzed using qRT-PCR in leaves and different stages ofreproductive tissue. The expression profile obtained for EcDmt102-like was relatively higher in reproductive tissue ofsexual plants, being down-regulated in apomictic ones. Expression ofthis gene was not observed in leaves from both genotypes. The expression pattern ofEcAgo104-like was complex and is still under study because occurrence ofa putative alternative splicing in the apomictic genotypes is being analysed. Our results support the reported roles played by this genes in gametophytic apomixis in other plant species.