Abstract Detail

Ecology

Del Valle, Jose Carlos [1], Buide, M. Luisa [2], Whittall, Justen Bryant [3], Narbona, Eduardo [1].

Effects of UV radiation and shading on anthocyanin accumulation and flower production in the shore campion.

One way to plants can adapt or acclimate to new environmental conditions is with the production of secondary metabolites. Anthocyanins, a group of flavonoids, may help plants to cope with the effects of a variety of biotic and abiotic stressors such as herbivory, pathogens, excess sun light radiation, cold, heat, drought or salinity. Anthocyanin pigments can be accumulated in every part of reproductive and vegetative plant organs, including petals, sepals, fruits, leaves or stems. Silene littorea is an annual plant with pink petals that grows in coastal populations from the Iberian Peninsula. In a previous study, we found a pattern of increasing accumulation of anthocyanins in petals, calyxes and leaves toward southern latitudes, which matches to a gradual increase of solar radiation and temperature, and a decrease of rainfall. Here, our aims are to investigate the role of solar radiation, including UV spectrum, in anthocyanin accumulation in reproductive and vegetative plant organs, and their relationship with flower and fruit production. We grow plants from four populations in a common garden experiment, located in a place with a solar irradiance similar to the maximum value found in natural populations. In a first experiment, plants were shaded to reduce 95% UV-PAR light. Open, full-sun plants showed at least two fold higher anthocyanin amount in calyxes and stems than shaded plants. In petals, anthocyanin production showed the same pattern, but differences were not significant. The total number of flowers of open plants was more than three times higher than those of shaded plants. In a second experiment, we carried out a UV filtration experiment using UVA+UVB transparent (methacrylate, transmittance > 280 nm) and UVA+UVB opaque (polycarbonate, transmittance > 380 nm) frames. In calyxes and stems, UV-present plants produced much higher amounts of anthocyanins than UV-absent plants. However, UV- plants showed more than double flower production that UV-present plants. In conclusion, our findings suggest that anthocyanins in calyxes and stems of S. littorea are only accumulated in response to UVA+UVB light. Whereas non-shaded full-sun microhabitats are better to reach high levels of total flower production in this coastal species, the high UVA+UVB radiation occurring in these sites seems to produce a reproductive cost. Future studies are needed to disentangling whether anthocyanins play a direct role in the protection from UV light and their possible relationship with plant fitness.

1 - Universidad Pablo de Olavide, Biologí­a Molecular e Ingenierí­a Bioquí­mica, Ctra. de Utrera, km 1, 41013, Sevilla, Spain, Seville, Seville, 41013, Spain
2 - University Pablo De Olavide, Ctra. De Utrera, Km 1, Sevilla, N/A, 41013, Spain
3 - Santa Clara University, Department Of Biology, 500 El Camino Real, Santa Clara, CA, 95053, USA

Keywords:
UV radiation
Shade
anthocyanins
flavonoids
Silene littorea
Caryophyllaceae
Flower production
Fruit production.

Presentation Type: Poster
Session: P, Ecology Section Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PEC023
Abstract ID:617
Candidate for Awards:None