State of the art unanswered questions about plant reproduction implies a series of complex cellular interactions involving a continuous exchange of signals between the pollen and the pistil. Processes in this topic concern to male and female gametogenesis, compatibility, pollen-stigma interaction and mechanisms of gamete attraction and fusion, and fertilization mechanisms, among others. True comprehension of events such as signal transduction pathways among cells, and how asymmetries are established among and within single plant cells are aims of this sub-line. Cellular, molecular and proteomic approaches to determine the function of gene products (including allergens) in the pollen grain and the pistil are developed. The success of reproduction is also an interesting topic under an agronomical perspective. Thus, during the next 50 years we will need to produce more and better quality food on an ever-decreasing amount of cultivatable lands. In this context, the knowledge of the genes and processes underlying plant reproduction will be essential to ensure a sustainable and affordable supply of food. Therefore, the major challenge for plant biologists and breeders will be to engineer new higher-yielding crop varieties without decreasing their quality by using these basic discoveries.