Abstract Detail

Recent Topics Posters

Roy, Rahul [1], Holl, Catherine [2], Solhaug, Erik [2], Carter, Clay [2].

Investigating the molecular aspects of red nectar from Nesocodon mauritianus (Campanulaceae), a gecko-pollinated species endemic to Mauritius.

Floral nectar is a carbohydrate rich reward for pollinators produced by structures known as nectaries. Nectar is usually clear but species which produce colored nectar are few and continue to fascinate biologists. One such species, Nesocodon mauritianus, endemic to the island of Mauritius produces bright red nectar at the base of its blue colored corolla. Nesocodon has been proposed to be pollinated by the day gecko Phelsuma sp, which also visits two other endemic species (of Mauritius) that produced colored nectar (Trochetia boutoniana and Trochetia blackburniana). The red color of N.mauritianus nectar has been reported to be due to the presence of aurones and the color is proposed to be an honest visual signal for floral reward. We have initiated studies to further analyze this fascinating floral nectar at the University of Minnesota CBS Conservatory which has 2 clones from Mauritius growing in a climate controlled greenhouse. We observed the progression of  N.mauritianus floral buds all the way to opening and designated presecretory and secretory stages for the species. We observed that nectar production usually starts in the afternoon and proceeds over almost 3 days past flower opening (which is unlike some of the other nectar producing model plants such as Brassica sp and Cucurbita sp).The coloration of the nectar also changes from being yellowish initially to a deeper red during peak secretion and the pH also progresses to being more alkaline (~9.5).  We also subjected the Nesocodon nectary to a transcriptomic analysis using RNA-Seq and are in the process of validating the data and discovering gene expression patterns. Analysis of the nectar for presence of proteins by PAGE revealed 3 bands that were analyzed by mass spectrometry at the UMN Center for Mass Spectrometry and Proteomics. One of the nectar proteins (NESO3) was identified as a carbonic anhydrase and confirmed by an in gel activity assay. We hypothesize that the carbonic anhydrase in the nectar is probably involved in pH modulation that results in a change in color of the nectar. Further studies on this fascinating floral trait are underway.

1 - University of Minnesota, Plant & Microbial Biology, 123 Snyder Hall, 1475 Gortner Ave, Saint Paul, MN, 55108, United States
2 - University of Minnesota, Twin Cities, 123 Snyder Hall, 1475 Gortner Ave, St. Paul, MN, 55108, United States

Keywords:
nectar
Pollinator attraction
endemic
mauritius
carbonic anhydrase
Campanulaceae
proteomics
Biochemistry
aurones
pollination.

Presentation Type: Recent Topics Poster
Session: P, Recent Topics Posters
Location: Grand Ballroom - Exhibit Hall/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 5:30 PM
Number: PRT025
Abstract ID:1320
Candidate for Awards:None