Expresión de cistatinas y su relación con la resistencia a Tilletia indica en trigo.

From the economic point of view, genetic improvement is one of the best options to fight karnal bunt caused by Tilletia indica fungus. Cystatin is a family of protease inhibitory proteins whose expression patterns may explain an effective resistance mechanism to karnal bunt. The objectives of this research were to evaluate the resistance/ susceptibility of bread wheat lines (Triticum aestivum) and durum (T. turgidum ssp. durum) to T. indica and to determine the relative expression levels of cystatin genes; as well as to determine the correlation of that expression with phenotypic resistance. A trial with 9 lines of wheat flour and 9 lines of durum wheat with different degrees of resistance was established. Thirty spikes per line with allantoic sporidia were inoculated and the percentage of infection determined. The cystatin genes (Wheat Cystatin) WC1, WC3 and WC5 were amplified by real-time PCR to quantify the normalized expression (ΔCt) of cystatin. The correlation coefficient was then obtained for normalized expression and percentage of infection. The percentages of infection were within the range of 15.85% to 36.78% in wheat flour and from 0.19% to 54.87% in durum wheat. Furthermore, normalized levels of cystatin expression were comparatively higher in resistant lines (p> 0.05). Significant correlation coefficients (p< 0.05) of WC3 and WC5 genes during all stages of sampling were shown, highlighting in vegetative (0.969), boot stage (0.841) and post-anthesis (-0.789) stages.