Testing collaboration
All members of the Scrum team are responsible for quality, testers, developers, and product owners. Usually each Agile team has an Agile tester responsible for verification and validation of the functional part of the application. We also have a product owner and a stakeholder to perform regression tests and give feedback on meeting acceptance criteria. Jira brings the plugin named Bonfire (http://www.atlassian.com/software/bonfire/overview) to help the team to coordinate and integrate testing into Jira/GreenHopper. Using the Bonfire plugin, you can coordinate the testing, fixing, and backlog management in a much better way.