Robustness of floral development: of evolutionary importance?
Robustness is a ubiquitously observed property of organisms and is a fundamental feature of complex evolvable systems. It can be described as the persistence of a trait under perturbations. In theory, a system must be able to maintain a high degree of robustness for it to function in erratic environments. Sometimes the apparent high degree of robustness is hard to explain. A good example of this is the floral structure of the Brassicaceae (mustard family). This family of angiosperms is composed of 4000 species and many of these have flowers composed of 4 petals, 4 sepals, 6 stamens and two carpels. Since the Brassicaceae either are predominately selfing or have general pollinators there appears to be no obvious explanation for this high level of conservation of the floral groundplan. The aim of this project is to test whether robustness was selected for during evolution using mutation accumulation (MA) lines. We also target candidate genes that may play a role in floral robustness using the CRISPR-Cas9 method of genome editing. Preliminary results indicate that the genetic robustness of organ length is not as strong as the robustness of floral organ number. Preliminary data also indicate that there may be a gradient of robustness in floral organ number across the different organ types. Maintaining a robust number for some organ types might thus be more critical than for others. Preliminary results indicate that mutant plants have been obtained via CRISPR-Cas9, however, further analysis needs to be conducted.