Evaluation of lettuce plants transformed with Snakin-1, a snakin/GASA family peptide, in abiotic stress situations

DARQUI F; RADONIC L; LÓPEZ N; HOPP, HE; VAZQUEZ ROVERE, C; LOPEZ BILBAO M

Foz de Iguazu

Congreso; International Plant Molecular Biology; 2015

ISPMB

SN1 peptide from the snakin/GASA family was first isolated from potato tubers andhas proven antifungal and antibacterial activity. These peptides have a GASAdomain rich in cysteine residues and able to form disulfide bonds, which givesthem antioxidant capacity. Their activity in abiotic stresses (salinity, temperature oroxidative) was recently shown. In order to evaluate SN1 biotechnological capacity,transgenic lettuce plants were obtained, homozygous lines were characterized andSN1 expression was evaluated by RT-PCR and Western blot.The aim of this work is to study the effect of SN1 overexpression on differentlettuce transgenic lines under thermal or salt stress conditions.Adult plants were incubated at 37°C during 3 hours a day for 15 days. One of thelines showed a significant lower elongation of the flower stem in comparison withthe non-transgenic line, while no differences were observed in normal temperature.Also, seeds were heat stressed during in vitro germination at 37°C for 4 hours andit was determined that seedlings of the transgenic lines have a smaller size thannon-transgenic ones. On the other hand, no differences between transgenic andnon-transgenic lines were observed when watering plants with 50 mM NaCl but theeffects of salt were noticeable in all these treated plants.These results show that SN1 peptide could modify the response of plants to heatstress, affecting germination and flowering, but not against salt stress. Furtheranalysis of this differential behavior in overexpressing plants could extendknowledge of the activity and regulation of SN1 peptide.