Plant Chimaeras and Mosaics

Abstract

Abstract Plant chimaeras and mosaics are not only found in our gardens as variegated ornamentals. They also constitute valuable research tools with a range of applications in developmental and molecular biology. For example, much of our knowledge about the development of the shoot and root apical meristems is derived from studying patterns of variegation, and where patterns persist throughout the plant, deductions can be made as to the fate of individual meristematic cells and the number and arrangement of initial cells giving rise to a variety of plant organs or structures. At a molecular level, chimaeras and mosaics can shed light on the cell autonomy of a certain trait, inform us about the propagation and movement of molecular signals and indeed allow us to directly compare genetically distinct tissues in a single organism to determine specific gene function. Key Concepts Meristematic tissue contains undifferentiated cells which divide and differentiate to produce the plant body. Apical meristems are found at the tips of shoots and roots and comprise of meristematic tissue. By grafting, plant parts are manually brought together to physically connect to each other and continue to grow. Fate mapping is a methodology used in developmental biology to understand how cell/s divide to contribute to an organism's body. Cell signalling involves obtaining, interpreting and/or transferring information between cells and their environment. Genetic transformation involves the transfer of foreign DNA and its integration into the genome of a host cell from where it is then passed onto daughter cells. Bud sports are lateral shoots or inflorescences which are visibly different to the rest of the plant.