Structural and functional characterization of regulatory sequences identified in long terminal repeats (LTR) of six potentially active retrotransposons from Solanum lycopersicum genome

VALDES MARIA BELÉN; ANDINO NATALIA; YAÑEZ ANAHÍ; PAZ ROSALIA

Congreso; 11 th International Congress of Plant Molecular Biology; 2015

LTR retrotransposons are the most abundant mobile elements in the genome of plants and their mobility appear to play an important role in the reorganization of genome induced by environmental changes. This propriety depends on the ability of their promoters to respond to different signaling pathways such as biotic and abiotic stresses. Previous research carried out by our group revealed that there are 737 complete, intact and potentially active retrotransposons distributed in 97 families inhabiting the tomato genome. Of these, only six have a frequency in the genome higher to 1%, indicating that their genomic amplification occur recently into the evolutionary history of tomato. The aim of this work is to study the regulatory modules of these six families in order to identify and characterize the different responsive elements (RE) under different environmental conditions. The search of RE was conducted on online PLACE software and frequency and position of this putative RE were validated analyzing multiple specific-family LTR aligned sequences. In total, we identified 87 ER, of which only 6 were common to the six analyzed retroelement families. These ER sequences were classified in four categories: a) Reproductive development, b) Growth, c) Abiotic stress and d) Biotic stress; being the proportion of RE within each category 26, 46, 22 and 6%, respectively. These results correlate with in silico expression analysis using EST libraries of tomato, and allow us to propose hypotheses for further work aimed at understanding the activity of these elements in tomato. Funding: D-TEC 0008/13 (AGENCIA, MINCyT, Argentina).