Transgenic potato lines with enhanced pathogen resistance did not show detectable differences to wild type plants when analyzed by exhaustive molecular and biochemical approaches

NARHIRÑAK, VANESA; ALMASIA, NATALIA INÉS; HOPP H. ESTEBAN; CARRARI FERNANDO; VAZQUEZ-ROVERE, CECILIA

Encuentro; VII ENCUENTRO LATINOAMERICANO Y DEL CARIBE DE BIOTECNOLOGIA; 2010

Snakin-1 (SN1) is an antimicrobial cysteine-rich peptide isolated from Solanum tuberosum active against a wide range of pathogens in vitro. Recently, we have demonstrated that the overexpression of this gene in potato plants (S1, S3, S5 lines) enhances resistance to economically important pathogens, Rhizoctonia solani and Erwinia carotovora, showing that SN1 has also in vivo antimicrobial activity. Although no evident phenotypic changes were observed in these lines, comparative transcriptomic and metabolomic analyses were carried out in order to evaluate possible unintended side effects. Transcriptional profiling of S1, S3 and wild type (WT) plants revealed 42 genes showing significant differences in expression levels in the S1 line but no changes were detected in S3. Most of these genes were found to be involved in cell wall metabolism. In order to explore modifications in plant cell wall composition/structure, FT-IR spectroscopy was performed in expanded leaves of transgenic lines. A model of principal component analysis (PCA) explaining about 86% of the data variance allowed discrimination of S1 samples from S3, S5 and WT ones. In parallel, a general overview of the primary metabolism of these lines was carried out by GC-MS analyses and a PCA model explained about 57% of the data variance with the same discriminatory power. Taken together, these results suggest that S3 and S5 are indistinguishable to their WT progenitor. Given the high protection levels displayed by these lines, they constitute an efficient biotechnological product that could decrease the use of pesticides reducing both costs and health risks.