Evolutionary trade‐offs in the chemical defense of floral and fruit tissues across genus Cornus

Abstract

Defense investment in plant reproductive structures is relatively understudied compared to the defense of vegetative organs. Here the evolution of chemical defenses in reproductive structures is examined in light of the optimal defense, apparency, and resource availability hypotheses within the genus Cornus using a phylogenetic comparative approach in relation to phenology and native habitat environmental data. METHODS: Individuals representing 25 Cornus species were tracked for reproductive phenology over a full growing season at the Arnold Arboretum of Harvard University. Floral, fruit, and leaf tissue was sampled to quantify defensive chemistry as well as fruit nutritional traits relevant to bird dispersal. Native habitat environmental characteristics were estimated using locality data from digitized herbarium records coupled with global soil and climate data sets. RESULTS: The evolution of later flowering was correlated with increased floral tannins, and the evolution of later fruiting was correlated with increased total phenolics. Leaves were found to contain the highest tannin activity, while inflorescences contained the highest total flavonoids. Multiple aspects of fruit defensive chemistry were correlated with fruit nutritional traits. Floral and fruit defensive chemistry were evolutionarily correlated with aspects of native habitat temperature, precipitation, and soil characteristics. CONCLUSIONS: Results provide tentative support for the apparency hypothesis with respect to both flower and fruit phenology, while relative concentrations of secondary metabolites across organs provide mixed support for the optimal defense hypothesis. The evolution of reproductive defense with native habitat provides, at best, mixed support for the resource availability hypothesis.

A multiplex approach of MS, 1D‐, and 2D‐NMR metabolomics in plant ontogeny: A case study on Clusia minor L. organs (leaf, flower, fruit, and seed)

“…Plants tend to allocate their resources to protect tissues or organ stages that are important towards their fitness. Production of secondary metabolites divert carbon reserves from tissue growth, and therefore the plant must follow a trade‐off of fast growing, maintenance, reproduction, and defence through physiological adaptations for survival 68,69 . The metabolites identified in C. minor are a part of various biosynthetic pathways.…”

“…Production of secondary metabolites divert carbon reserves from tissue growth, and therefore the plant must follow a trade-off of fast growing, maintenance, reproduction, and defence through physiological adaptations for survival. 68,69 The metabolites identified in C. minor are a part of various biosynthetic pathways. The high levels of polyprenylated benzophe- Therefore, 1D analysis used in this study provided direct quantification of selected metabolites, while 2D analysis reduced spectral overlap and added molecular connectivity information that led to a clearer metabolite identification.…”

Evolutionary history and ecology shape the diversity and abundance of phytochemical arsenals across monkeyflowers

“…In addition, further work might investigate phytochemistry of floral tissue, as a complement to the study of foliar phytochemistry done here (e.g. De La Pascua et al., 2020). Combined, future work may elucidate how intraspecific trade‐offs, environmental factors and evolutionary processes contribute to phytochemical variation across species.…”

The Phenological phases of development of Cornus florida L. under conditions of introduction in Ukraine

“…They have been studied and used to determine the effect of air temperature on the initiation of dogwood flowering, to develop spring indices (Schwartz et al, 2013), to analyze trends in spring onset in the temperate regions of the Northern Hemisphere, and long-term changes in plant phenology in the Northeastern United States, and also to clarify the dynamics of the concentration of organic substances in plants during the growing season, etc. (Lieth and Radford, 1971;Reader, 1975;De La Pascua, 2020;Fuccillo Battle et al, 2022).…”