Abstract Detail

Reproductive biology

Davis, Sandra [1], Dudle, Dana A [2].

Floral pinkness and anthocyaninidin synthase (ANS) expression during floral development in the protandrous herb Saponaria officinalis..

Saponaria officinalis (bouncing bet) produces protandrous flowers. As the flowers transition from staminate to pistillate phase, a series of additional morphological changes occur such that staminate- and pistillate-phase flowers differ in size, shape, and color. However, we know little about the proximate mechanisms involved in these changes and their relative timing. Here we report on phenological investigations performed to answer these questions at the morphological and cellular levels. In summer 2015, we observed marked flowers on plants growing in an experimental garden. Every 3 hours between 6am and 9pm, we estimated the flowers’ sexual stage and recorded their color according to a scale of “pinkness” created from the natural variation observed in local populations. Previous results have shown that increased coloration of petals in S. officinalis is associated with an increase in concentration of anthocyanin pigments. A major enzyme involved in one of the final steps in the production of anthocyanins is anthocyanidin synthase. Therefore, we hypothesized increased pigmentation in pistillate-phase flowers compared to staminate-phase flowers should parallel an increase in the expression of the ANS gene (ANS). We marked buds on 10 plants and collected them at 5 developmental stages. RNA was isolated from the petals from these flowers using guanidinium-phenol-chloroform extraction, and converted to cDNA using reverse transcriptase. A portion of ANS cDNA and actin cDNA (an internal control) was amplified by PCR using a primer pair specific for ANS and a universal actin primer pair. The results were used to create a time-course of ANS expression that we compared with the morphological changes we observed during floral development. These studies demonstrated that floral pinkness, associated with anthocyanin production, increased gradually throughout the lifetime of the flowers, for several days after flowers entered the pistillate phase. The pattern of ANS expression within flowers over time was less straightforward than our observations of floral pinkness, indicating that microenvironmental factors experienced by individual flowers on a plant interact with floral age to influence floral color.

1 - University Of Indianapolis, Department Of Biology, 1400 E. HANNA AVE., Indianapolis, IN, 46227, USA
2 - DEPAUW UNIVERSITY, Department Of Biology, 114 Olin Hall Of Biological Sciences, 1 E. Hanna Street, GREENCASTLE, IN, 46135, USA

Keywords:
protandry
flower color
sexual dimorphism
anthocyanins.

Presentation Type: Poster
Session: P, Reproductive Biology 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: PRP003
Abstract ID:485
Candidate for Awards:None