Although flower color polymorphism has been mostly studied from a pollinator mediated selection standpoint, few studies have also examined whether these polymorphisms can have cascading effects (e.g., plant defense traits). Extensive molecular studies on the flavonoid pathway that produces anthocyanins have revealed that the loss of floral color can be attributed to mutations in any of the transcription factors that regulate the pathway (bHLH, MYB, and WD40) leading to the loss of expression of the structural genes (e.g., Chi, F3h) or due to mutations in the structural genes themselves in the cis-regulatory regions or in coding sequences. In Solanum eleaegnifolium, a worldwide invasive weed native to United States, we have found that the populations in the Greek mainland of Thessalonki exhibits flower color polymorphism with white color morphs present in very low frequency (<1%) when compared to their blue counterparts.
Detailed examination of morphological, reproductive and defense traits between the blue and white morphs revealed that these color morphs vary in these traits with potential trade-offs between reproduction (fruit set) and defense (herbivore feeding, herbivore induced plant volatiles, and adult moth oviposition). A detailed analysis of these traits and their ecological significance will be discussed with data derived from field pollination experiments, laboratory bio assays, quantification of anthocyanin pathway and plant volatiles, and, sequencing and expression analyses of the candidate genes.