The three of them, dissent, persecute and tolerance are three different manners of reaction to another person's opinion, viewpoint on some specific issue or way of life, specially regarding those which differ from the own one.
Tolerance implies fully accepting and respecting different viewpoints, and even valuing such diversity. Dissent consists on replying with different arguments and ideas. If persecution is performed, the differing opinion is repudiated and tried to be silenced.