Clonado y Caracterización del Gen snakin-1.

ALMASIA, NATALIA INÉS; BAZZINI, ARIEL ALEJANDRO; DENGIS, ANDREA; CABRERA,TERESA; HOPP H. ESTEBAN; VAZQUEZ-ROVERE, CECILIA

Boca Chica - Santo Domingo - República Dominicana.

Congreso; V ENCUENTRO LATINOAMERICANO Y DEL CARIBE DE BIOTECNOLOGIA VEGETAL. (REDBIO 2004); 2004

Snakin-1 gene encodes for a peptide with in-vitro antimicrobial and antifungal properties. In this work five genetic variants of this gene were identified from Solanum species (S. tuberosum spp tuberosum cv Kennebec, S. commersonii and S. chacoense). Comparative bioinformatics analysis of the nucleotide sequences showed identities values between 91 and 98%. As all detected differences were silent because of the degenerated genetic code, the aminoacidic sequences revealed 100% homology. These results suggest that, at least in this genus, snakin-1 gene could be an important defense component of plants. The aim of the second part of this work was to deepen in the knowledge of the in-vivo role of the snakin-1 gene. So this part of the project consisted in the production of transgenic potato plants that carry three different constructs. The first one is able to over-express the snakin-1 gene, the second one is an antisense construct and the third one is able to trigger specific post-transcriptional gene silencing. Transgenic plants were checked by PCR, Southern blot and RT-PCR. Selected ones were challenged with Rhizoctonia solani and high level of protection was shown in the plants that constitutive over-expressed snakin-1 gene with respect to the non-transformed plants. Two over three lines transformed with the antisense construct displayed the same behavior or were even more susceptible than control plants. In contrast, the third one showed a higher level of protection. Finally, one of the two evaluated lines able to trigger specific post-transcriptional gene silencing showed the maximum grade of susceptibility among the evaluated transformed plants. Even thought these results are preliminary, they may suggest that snakin-1 gene could be an important in-vivo antifungal defense component in plants.