The non-specific lipid transfer protein N5 of Medicago truncatula is required for efficient nodulation during symbiosis with N-fixing rhizobia

Transgenic adventitious hairy roots carrying a hairpin construct (MtN5hp) for MtN5 silencing are impaired in nodulation, showing a 50% of reduction in the number of nodules compared with inoculated control roots (Pii et al., 2009). This finding indicates that MtN5 is required in the roots for a successful establishment of the symbiotic interaction with S.meliloti. In order to further support the results obtained in transgenic composite plants, we have undertaken the stable genetic transformation of M. truncatula with A. tumefaciens bearing the MtN5hp construct. The analyses carried out on stable-transformed MtN5-silenced plants confirm the role of the lipid transfer protein N5 in root nodule formation.