The open growth pattern in plants is due to the presence of meristems, i.e. embryonic tissue with the capacity to form primordia. Molecular and cellular studies indicate that primordium formation is a self-regulating space-dependent process linked with a directed auxin flow. In contrast to the vegetative shoot apical meristem (SAM), floral meristems (including flower and floral unit meristems) lack apical growth and instead expand before and during primordium formation. The combination of determinate growth and the ongoing change of meristem geometry result in diverse developmental constraints and options explaining the high plasticity of primordium initiation patterns and the enormous potential of floral meristems to diversify.
The meristem level is usually disregarded when morphogenetic processes are explained by developmental genetic studies. However, gene expression and hormone flow depend on meristem conditions, which on their side are influenced by physical parameters. Spatial constraints, mechanical pressure, floral integration, differential timing of primordium initiation and development, heterochrony, heterotopy, meristem expansion and novel space generation are only some examples indicating the need for meristem studies. Adequate modeling and generalizations of developmental processes are only possible when all levels of development from gene and hormones to meristems and phenotypes are considered. This Research Topic on floral meristems aims to summarize the present knowledge on developmental conditions, regulation at the molecular scale, and constraints in floral meristems and to bridge the gap between developmental genetics, developmental morphology, and computer modeling.
The open growth pattern in plants is due to the presence of meristems, i.e. embryonic tissue with the capacity to form primordia. Molecular and cellular studies indicate that primordium formation is a self-regulating space-dependent process linked with a directed auxin flow. In contrast to the vegetative shoot apical meristem (SAM), floral meristems (including flower and floral unit meristems) lack apical growth and instead expand before and during primordium formation. The combination of determinate growth and the ongoing change of meristem geometry result in diverse developmental constraints and options explaining the high plasticity of primordium initiation patterns and the enormous potential of floral meristems to diversify.
The meristem level is usually disregarded when morphogenetic processes are explained by developmental genetic studies. However, gene expression and hormone flow depend on meristem conditions, which on their side are influenced by physical parameters. Spatial constraints, mechanical pressure, floral integration, differential timing of primordium initiation and development, heterochrony, heterotopy, meristem expansion and novel space generation are only some examples indicating the need for meristem studies. Adequate modeling and generalizations of developmental processes are only possible when all levels of development from gene and hormones to meristems and phenotypes are considered. This Research Topic on floral meristems aims to summarize the present knowledge on developmental conditions, regulation at the molecular scale, and constraints in floral meristems and to bridge the gap between developmental genetics, developmental morphology, and computer modeling.
