Abstract Detail

Recent Topics Posters

Szubryt, Austin [1], Liu, Xian [2], Rang, Wei [3], Gibson, David [4], Geisler, Matthew [1], Cheng, Qiang [3], Geisler-Lee, Jane [1].

Conspecific Shoot and Root Behaviors Regarding Intraspecific Competition of Arabidopsis thaliana.

Plants compete for light, water, nutrients and space. Our research sought to determine mechanisms underlying intraspecific (same species) competitive behavior in the plant Arabidopsis thaliana (Brassicaceae). Both aboveground (shoot) and belowground (root) tissues respond to competition in early development within 32 days after planting (DAP). Four treatments were established in soil filled square pots and optically clear gel media in transparent boxes (to see roots). The control (C) contained five plants in a soil pot or gel box, with a transgenic green florescence protein plant (center plant) in the middle of the container and four conspecific (same species and ecotype) non-fluorescent wild type plants at four corners to create a competitive environment. Competitor plants have the effect of reducing nutrient levels, creating a negative nutrient gradient, while they also secrete root exudates in a positive gradient around the competitor plant. These two hypothesized competitive factors, low media nutrients (L) and the presence of root exudates (H) were tested by replacing competitor plants in two corners to evaluate changes in the center plants behavior in response to these conditions. A second, procedural control (PC), had two portions of media removed and replaced immediately to control for effects of soil and gel disturbance. Two of the four corner positions opposite each other were disrupted for the L, H, and PC pots/boxes by utilizing half-strength nutrient media, used media (where plants grown here until 32 DAP), or temporarily removed media, respectively. The shoots (as rosette diameters) of center plants in C pots grew the largest until 28 DAP, although the L plants grew the most by 32 DAP followed by C, then H, and finally PC. Diminished nutrients in L boxes seem to induce a short-term growth increase, although root exudates in tandem with reduced nutrient concentrations (seen in H boxes) appear to suppress growth slightly. Thus far, root exudates appear to alter root growth, particularly orientation. We hypothesize that currently undescribed secreted compounds in root exudates in H boxes are responsible for the noticeable effects on young root growth and indicate a negative correlation with growth. Ultimately, root exudates may mimic presence of existing plants to deter center plants from growing in that direction while in contrast, replacement of competitor plants with low nutrient soil stimulates vigorous growth of the center plant within 32 DAP.

1 - Southern Illinois University Carbondale, Department of Plant Biology, Carbondale, IL, 62901, USA
2 - Southern Illinois University Carbondale, Environmental Resource and Policy Program, Carbondale, IL, 62901, USA
3 - Southern Illinois University Carbondale, Department of Computer Science, Carbondale, IL, 62901, USA
4 - Illinois University Carbondale, Center for Ecology, Carbondale, IL, 62901, USA

Keywords:
Arabidopsis
competition
Conspecific
Exudate.

Presentation Type: Recent Topics Poster
Session: P, Recent Topics Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM
Number: PRT007
Abstract ID:1175
Candidate for Awards:None