Many people believe that it is our fate to travel to other planets.
In order to do so, there must be some sort of vegetation in order to feed the space pioneer. Other than the food taken with us, plant life is the only other option. Plants also serve other purposes - they purify the water, generate oxygen, and scrub carbon dioxide. They themselves can either make life or break it. Their purpose was to begin the process of redesigning plants to meet the needs of future space settlers.