Proteomics Approach for Analyzing Oat Lines with Different Freezing Tolerance.

To compare freezing tolerance in a total of 24 oat (Avena sativa L.) lines, 4 weeks old seedlings were cold-acclimated at 4°C for 24 h and frozen at -10°C for 8 to 22 h. The frozen seedlings were transferred and grown under a normal condition for another one month, then the percent kill of oat seedlings were recorded. After 8 h of freezing, 33% of a line was killed but all plants in 11 lines were survived. Less than 50% of plants were survived in 13 lines after 22 h of freezing, but 10 lines showed up to 96% of survival rate. The most tolerant line was ‘Kwiri36’ in which 50 percent kill was calculated after 28 h of freezing. In order to obtain detailed insight into the effect of freezing on apical meristem in two oat lines with different freezing tolerance, we have conducted a gel-based proteomic approach. For this, the apical meristem of oat seedlings was sampled before and after cold-acclimation and after freezing for 10 h. For proteomics evaluation, we have optimized an improved protein extraction protocol based on a modified lysis buffer, and an immobilized pH gradient-based two dimensional (2D) gel electrophoresis-based separation of the extracted proteins. Our results revealed a dramatic increase in the solubility of proteins from the tested tissue and increased spot resolution on 2D gels. Further analysis on freezing tolerance of oat lines will be discussed.