Isolation y characterization of snakin-1 promoter.

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

Bariloche, Argentina.

Congreso; XXXIX REUNION ANUAL SAIB; 2003

Snakin-1 (SN1) is a newly characterized antimicrobial peptide isolated from potato tubers that has been found to be active against bacterial and fungal pathogens from potato and other plant species. Snakin-1 causes aggregation of both gram-positive and gram-negative bacteria. Since gene expression has been detected in tubers, stems, axillary buds, and young floral buds, the expression pattern of gene StSN1 suggests that protein SN1 may be a component of constitutive defense barriers, especially those of storage and reproductive plant organs. Its regulatory region has not been studied until now. We report here the cloning, sequencing and analyis of the promoter region placed upstream of Solanum tuberosum snakin-1 gene. A 671 pb fragment was amplified by Inverse polymerase chain reaction (IPCR) using potato Kennebec germplasm as template. After cloning into pGemT easy vector, it was fully sequenced and probable TATA and CAAT motives were identified. Two upstream sequences: a 671 bp fragment corresponding to the whole cloned sequence and a short version of 448 pb were used to transiently express betaglucuronidase (GUS) in bombarded potato explants. GUS expression was detected in stem apex and axillary buds. This suggests that the isolated promoter sequence conserved its tissue specifity. In addition we obtained transgenic potato and tabacco plantas that express GUS under the control of the same cloned fragments. Further studies will clarify the influence of differents growth regulators on this new promoter in order to better understand its physiological functions.