Analysis of the biological role of potato Snakin/GASA peptides.

NAHIRÑAK, V; GONZALEZ DE URRETA, M; BARRIOS-BARÓN, P; RIVAROLA, M; PANIEGO, N; HOPP, HE; ALMASIA, NI; VAZQUEZ ROVERE, C

Montpellier

Simposio; Antimicrobial Peptide Symposium; 2016

CNRS-Universidad de Montpellier

Snakin/GASA peptides are widely distributed among plant species and have been involved in plant development and stress responses. They maintain 12 cysteines in conserved positions of the C-terminus, probably responsible for their structure and their activity as antioxidants. Most of these genes are regulated by hormones and some participate in the interaction between different hormonal signaling pathways. Snakin-1 and Snakin-2, two AMPs isolated from potato, were reported to be active in vitro against different plant pathogens. Our group demonstrated that overexpression of Snakin-1 in potato enhanced fungi and bacteria resistance. Moreover, we showed that Snakin-1 silencing affected cell division, leaf primary metabolism and cell wall composition demonstrating that it has additional roles in growth and development. Recently, a genome-wide analysis suggested that in potato this family consists of 18 members grouped into three subfamilies. We are interested in the functional characterization of one member of each Snakin/GASA subfamily in potato (Snakin-1, Snakin-2 and Snakin-3). Interestingly, we found that Snakin-1, Snakin-2 and Snakin-3 expression is affected by bacterial and/or fungal inoculation in the cultivar Kennebec. These results strengthen the participation of Snakin-1 and Snakin-2 in biotic stress tolerance and suggest that Snakin-3 is also involved in plant defense.In order to gain more insights into the molecular mechanism underlying the role of these genes, analyses of Snakin-1 transgenic and WT transcriptomes were further performed and reactive oxygen species accumulation and endogenous levels of plant hormones were determined. Our results suggested the involvement of Snakin-1 in redox homeostasis and hormonal crosstalk. In addition, Snakin-1, Snakin-2 and Snakin-3 are being expressed in a bacterial system in order to study their activities in vitro and contribute to the understanding of their mode of action.