Characterizing Chemical Signaling Between Honey Locust and Rhizobia Using HPLC/MS
Mentor 1
Gyaneshwar Prasad
Location
Union Wisconsin Room
Start Date
5-4-2019 1:30 PM
End Date
5-4-2019 3:30 PM
Description
Many Legumes form a symbiotic relationship with Rhizobia that leads to formation of specialized structures called nodules in which the bacteria fix atmospheric nitrogen in exchange of carbon from the host-plant. Chemical signaling plays a crucial role in the symbiotic interaction. The host-plant secreted flavonoids/isoflavonoids are recognized by the symbiotic Rhizobia leading to the rhizobial production of Nod factors that are in turn recognized by the host plant. Although nodule formation is common throughout the legumes, there are many legumes, especially in the Caesalpinioideae saubfamily, which do not form root nodules. However, the reasons for the non-nodulation are not known. To investigate if non-nodulating legumes can initiate symbiotic interactions with rhizobia, we assayed root and seed exudates of Honey Locust (Gleditsia triacanthos L.) using coupled high-performance liquid chromatography and mass spectroscopy (HPLC-MS). Analysis of the exudates showed that Honey Locust roots secrete apigenin, diadzein, luteolin, and naringenin, all of which are known to be involved in symbiosis in various legumes. These results suggest that Honey Locust is capable of an initial symbiotic communication with Rhizobia. This research has important applications due to the importance of the Rhizobia symbiosis in modern agriculture, as well as to further characterize the symbiotic relationship in a legume species that does not nodulate.
Characterizing Chemical Signaling Between Honey Locust and Rhizobia Using HPLC/MS
Union Wisconsin Room
Many Legumes form a symbiotic relationship with Rhizobia that leads to formation of specialized structures called nodules in which the bacteria fix atmospheric nitrogen in exchange of carbon from the host-plant. Chemical signaling plays a crucial role in the symbiotic interaction. The host-plant secreted flavonoids/isoflavonoids are recognized by the symbiotic Rhizobia leading to the rhizobial production of Nod factors that are in turn recognized by the host plant. Although nodule formation is common throughout the legumes, there are many legumes, especially in the Caesalpinioideae saubfamily, which do not form root nodules. However, the reasons for the non-nodulation are not known. To investigate if non-nodulating legumes can initiate symbiotic interactions with rhizobia, we assayed root and seed exudates of Honey Locust (Gleditsia triacanthos L.) using coupled high-performance liquid chromatography and mass spectroscopy (HPLC-MS). Analysis of the exudates showed that Honey Locust roots secrete apigenin, diadzein, luteolin, and naringenin, all of which are known to be involved in symbiosis in various legumes. These results suggest that Honey Locust is capable of an initial symbiotic communication with Rhizobia. This research has important applications due to the importance of the Rhizobia symbiosis in modern agriculture, as well as to further characterize the symbiotic relationship in a legume species that does not nodulate.
