Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Powell, Adrian [1], Halitschke, Rayko [2], Kessler, Andre [3], Doyle, Jeff [4].

Rhizobial symbiosis and allopolyploidy in Glycine subgenus Glycine.

In plants, polyploidy is a genetic and evolutionary phenomenon known to affect biotic interactions. A key type of biotic interaction for many legumes is symbiosis with rhizobial bacteria, in a process referred to as nodulation. These symbioses involve bacteria that are able to fix atmospheric nitrogen, rendering it accessible to the plants; thus, the ability to form such associations enables these plants to address the critical challenge of nitrogen acquisition. The present study examines the effects of allpolyploidy on nitrogen-fixing symbioses between rhizobial bacteria and members of the Glycine subgenus Glycine allopolyploid complex. This complex provides something approaching a replicated natural experiment in allopolyploidy, in which a small number of extant diploid progenitor species contributed genomes to several independently formed polyploids. Inoculation trials with a variety of bacterial strains indicate differences between allopolyploids and their diploid progenitors in response to inoculation. The specificity of this symbiosis is governed by numerous stages of signal, response, and interaction, each of which requires compatibility. Flavonoids are a class of signaling compounds produced by plant hosts and implicated in the initiation of rhizobial symbioses. It is also known that polyploidization and hybridity (both of which are features of allopolyploids) can alter flavonoid biosynthetic pathways. Our preliminary data show variation between allopolyploids and diploids in their exudate profiles, particularly in levels of the key signaling isoflavonoid daidzein. Additional molecular and genetic processes governing these interactions and their modulation in allopolyploids will also be explored.

Broader Impacts:

1 - Cornell University, Plant Biology, Ithaca, NY, 14850, USA
2 - Cornell University, Ecology & Evolutionary Biology, Ithaca, NY, 14850, USA
3 - Cornell University, E445 Corson Hall, Ithaca, NY, 14853, USA
4 - Cornell University, 412 Mann Library Building, ITHACA, NY, 14853-4301, USA

Keywords:
Flavonoids
Glycine subgenus Glycine
Rhizobial symbiosis
allopolyploidy.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PSB002
Abstract ID:627
Candidate for Awards:None