POTATO SNAKIN/GASA FAMILY: BASIC AND APPLIED STUDIES

Snakin/GASA proteins are widely distributed among plant species. All family members maintain 12 cysteines in the C-terminus in highly conserved positions of the aminoacid sequences. Despite their common features, their functions are not completely elucidated and little is known about their mode of action. Snakin/GASA peptides have been shown to participate in plant growth and development as well as in plant responses to biotic and abiotic stresses. In study this gene family in potato we carried out a genome-wide analysis in Solanum tuberosum cv. Kennebec. We found 18 members which can be classified into three subfamilies. We showed that spatial and hormonal regulation of each gene is highly specific, dependent on the plant developmental stage and on the genotype analyzed. Snakin-1 (SN1) is the first member of the Snakin/GASA family isolated from S. tuberosum. Is active in vitro against bacteria, fungus, yeasts and animal/human pathogens. We demonstrated that it also confers in vivo protection against commercially relevant pathogens in overexpressing potato, wheat, and lettuce plants. Besides having a function in defense, we demonstrated, performing an integrated study of SN1 silenced potato plants, that SN1 plays a role in growth and development. Its silencing affects cell division, leaf metabolism, and cell wall composition and recently we demonstrated that SN1 participates in redox balance and in a complex crosstalk among different hormones. Evidence supports a paramount role to SN1 in the mechanism underlying growth and immunity balance. Furthermore, SN1 may be a promising candidate in preservation, and pharmaceutical or agricultural biotechnology applications.