Molecular and functional characterization of S-RNases from a natural population of Nicotiana alata

JUAN A ROLDÁN, RODRIGO QUIROGA, HERNÁN J ROJAS AND ARIEL GOLDRAIJ

San Miquel de Tucuman

Congreso; SAIB; 2009

Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular

  We report here the molecular and functional characterization of novel S-RNase candidates identified from a natural population of Nicotiana alata. Using degenerated oligonucleotides based on conserved domains of S-RNases, we identified by RT-PCR ten style sequences homologous to S-RNases, including three previously reported functional S-RNases and seven novel S-RNase candidates. Six of these candidates showed, by allele-specific RT-PCR, plant-specific expression in the natural population and style specific amplification, which increased gradually during bud maturation, consistent with the reported S-RNase expression. In contrast, the S63 sequence was present in all plants examined and was ubiquitously expressed in different organs and bud developmental stages. Genetic analysis confirmed the association with self-incompatible function in five S-RNase candidates, while S5 and S63 appeared to be non-functional relic S-RNases. Phylogenetical analysis showed the Nicotiana alata S-RNases were included in eight transgeneric lines confirming that this species represents a broad sample of allelic variation at the S-locus of the Solanaceae.