Nectary Diversity and Evolutionary Trends
Convergent Evolution
Despite serving similar functions, floral nectaries have evolved independently over a hundred times in angiosperms. In lineages that have convergently evolved the same type of nectary, such as Arabidopsis, Mimulus, Petunia, and Cucurbita, similar cellular structures and genetic pathways are often co-opted for nectary development and nectar secretion. However, the molecular basis underlying this repeated convergence remains largely unknown. In contrast, lineages that produce structurally distinct nectaries, such as Aquilegia and Mimulus, employ different transcription factors to specify nectary identity yet utilize overlapping biochemical pathways for nectar production. How these diverse regulatory inputs are integrated into shared metabolic outputs is also unclear. We aim to address these outstanding questions using comparative genomics and ChIP-seq across distantly related taxa.
Photo from Dr. Scott Hodges
Adaptation to Different Pollinators
Both Aquilegia and Mimulus experienced recent adaptive radiations when migrating across western North America and encountering diverse pollinator communities. These pollinator shifts are accompanied by changes in nectary size and nectar volume. Through a combination of QTL mapping and transcriptome profiling, we are actively identifying the genetic factors responsible for these morphological and physiological adaptations.
Domestication and Human Selection
Nectar-mediated pollinator interactions are critical for fruit set in many crop species, while in some ornamental plants, nectaries have been reduced or lost entirely through domestication. Using fruit crops and ornamental species within the Rosaceae family as a model, we are investigating how domestication has shaped nectary structure and function over time.