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United States Department of Agriculture

Agricultural Research Service

Research Project: FORAGE SYSTEMS FOR SUSTAINABLE ANIMAL PRODUCTION IN THE MID-SOUTH

Location: Forage-Animal Production Research

Title: Gene expression and metabolite analysis of endophyte infected and uninfected tall fescue clone pairs under water deficit conditions

Authors
item DINKINS, RANDY
item Nagabhyru, Padmaja -
item Schardl, Christopher -

Submitted to: International Symposium of Molecular Breeding of Forage Turf
Publication Type: Abstract Only
Publication Acceptance Date: April 4, 2012
Publication Date: June 4, 2012
Citation: Dinkins, R.D., Nagabhyru, P., Schardl, C.L. 2012. Gene expression and metabolite analysis of endophyte infected and uninfected tall fescue clone pairs under water deficit conditions. Proceedings of the 7th International Symposium of the Molecular Breeding of Forage Turf. pgs 32-38.

Technical Abstract: Tall fescue (Lolium arundinaceum) plants symbiotic with the endophytic fungus, Neotyphodium coenophialum (E+), have better survivability and persistence under stressful conditions, especially under drought stress, than plants lacking the endophyte (E-). To understand more about the grass-endophyte interactions and how endophyte affects the host plant physiology and gene expression, we conducted a time course water deficit stress experiment using genetically identical E+ and E- clone pairs of tall fescue. Upon re-watering, survival and retillering was significantly greater for E+ than E- plants starting from days 2 - 3 of the stress conditions. RNA-Seq analysis of pseudostem derived RNA comparing E+ and E- of Day 2 stress and control plants was done. CLCbio Genomic Workbench was used to generate contigs using the tall fescue cDNA sequences previously submitted to NCBI as a reference. The contig sequences were analyzed using Blastx and Blastn against the Arabidopsis thaliana, Brachypodium distachyon and rice genomes for comparison and putative annotation assignment. Only a few contigs/genes were differentially expressed between the E+ and E- plants under non-stressed conditions, but a large number were differentially expressed (>2X) between E+ and E- plants under the water deficit conditions. In addition, as expected, a large number of contigs/genes were differentially expressed due to the stress treatment. Metabolomic analyses revealed higher accumulation of the free sugars and proline in E+ plants at early days of onset of stress compared to E- plants. Loline alkaloids and mannitol, fungal metabolites, also increased with water stress. Analysis of specific genes is ongoing and results will be presented.

Last Modified: 9/10/2014
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