Background: The endophytic fungus, Neotyphodium coenophialum, can enhance drought tolerance of its host grass, tall fescue. To investigate endophyte effects on plant responses to acute water deficit stress, we did comprehensive profiling of plant metabolite levels in both shoot and root tissues of genetically identical clone pairs of tall fescue with endophyte (E+) and without endophyte (E-) in response to direct water deficit stress. The E- clones were generated by treating E+ plants with fungicide and selectively propagating single tillers. In time course studies on the E+ and E- clones, water was withheld from 0 to 5 days, during which levels of free sugars, sugar alcohols, and amino acids were determined, as were levels of some major fungal metabolites.Results: After 2-3 days of withholding water, survival and tillering of re-watered plants was significantly greater for E+ than E- clones. Within two to three days of withholding water, significant endophyte effects on metabolites manifested as higher levels of free glucose, fructose, trehalose, sugar alcohols, proline and glutamic acid in shoots and roots. The fungal metabolites, mannitol and loline alkaloids, also significantly increased with water deficit.Conclusions: Our results suggest that symbiotic N. coenophialum aids in survival and recovery of tall fescue plants from water deficit, and acts in part by inducing rapid accumulation of these compatible solutes soon after imposition of stress.
|Journal||BMC Plant Biology|
|State||Published - Sep 9 2013|
Bibliographical noteFunding Information:
This research is funded by USDA-ARS Specific Cooperative Agreement 200911131030. The authors are grateful for help and suggestions from Dr. Bruce A. Downie in HPLC for carbohydrates. The authors also thank J. Douglas Brown and W. Troy Bass for maintaining plants, and Dr. Lowell P. Bush and Dr. Fanniel F. Fannin for providing the loline alkaloid standard. The authors also acknowledge the ERTL facility at the University of Kentucky for allowing use of the LCMS and for technical assistance. This is publication number 13-12-101 of the Kentucky Agricultural Experiment Station, published with approval of the director.
- Amino acids and lolines
- Fungal endophyte
- Neutral sugars
- Tall fescue
- Water deficit stress
ASJC Scopus subject areas
- Plant Science