Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Improvement of Biotic and Abiotic Stress Tolerance in Cool Season Grasses

Location: Forage Seed and Cereal Research

Project Number: 2072-21000-045-00
Project Type: Appropriated

Start Date: Feb 26, 2013
End Date: Feb 25, 2018

Objective:
The overall goal of this research is to reduce the impact of abiotic and biotic stresses on the quality and productivity of grasses that serve as the basis for livestock production, turf, and bioenergy. Objective 1: Improve grass germplasm by developing molecular and biological resources that can be applied to reduce the impact of abiotic stresses on the productivity of grasses used for livestock production, turf and bioenergy. Sub-objective 1.1: Isolate and identify endophytes from native grasses from saline environments at the Oregon Coast to find novel endophytes that can be utilized to improve persistence and yield of forage (Festuca sp.), turf (Lolium sp.), and bioenergy (switchgrass and Miscanthus sp.) grasses along with cereals (rice and wheat) in environments with substandard water quality. Sub-objective 1.2: Identify genes and signaling components involved in abiotic stress responses in the model grasses Lolium temulentum and Brachypodium to evaluate their utility for improving the performance of turf, forage, and bioenergy grasses in diverse end-use environments. Objective 2: Reduce the impact of weeds and stem rust, two biotic stresses that negatively impact seed production and the utilization of grasses for livestock production, turf, and bioenergy. Sub-objective 2.1: Conduct field trials to evaluate the efficacy of a bioherbicide in reducing the germination of cheatgrass, medusahead, and annual bluegrass weeds in seed production fields and rangeland. Sub-objective 2.2: Identify mapping and marker tools that enable the selection of perennial ryegrass (Lolium perenne) germplasm with resistance to stem rust.

Approach:
Foundational and applied research will be conducted to reduce the impact of abiotic and biotic stresses on the quality and productivity of grasses that serve as the basis for livestock production, turf, and bioenergy. Objective 1 focuses on the improvement of grass germplasm by developing molecular and biological resources that can be applied to reduce the impact of abiotic stresses on the productivity of grasses. It has been shown that various types of endophytes can enhance a plant's ability to tolerant stress. Research will be conducted to isolate and identify novel bacterial or fungal endophytes from native grasses growing in saline environments along the Oregon Coast. These endophytes will be isolated from plant tissues and seeds, identified, characterized, and reintroduced into a model grass species that is salt sensitive, in order to determine if the novel endophytes are able to improve the plant's ability to grow when subjected to salt stress. There is limited knowledge on the perception or molecular responses to wounding in grasses and how these responses affect persistence, the regrowth of new tissues and the long-term nutritional quality of the grass. Research will be focused on identifying wound inducible genes, locally and systemically, and the signals involved in wounding in forage and turf related grasses. Since most stresses have an oxidative stress component, identification and utilization of oxidative stress response factors may provide useful strategies for increasing tolerance to multiple stresses in grasses. Using bioinformatics approaches, homologs of transcription factors that have been shown to be involved in mediating the oxidative stress responses in eukaryotic systems will be identified. Homologs of the genes will be identified, isolated from grass species and over-expressed in a model grass. These transformed plants will be tested to determine if the over-expression of the homolog gene will improve the tolerance of the plant to different of abiotic stresses. Research conducted in Objective 2 will reduce the impact of weeds and stem rust, two biotic stresses that negatively impact seed production and the utilization of grasses for livestock production, turf, and bioenergy. Stem rust, caused by Puccinia graminis, is a biotic stress that reduces the yield and quality of grasslands where perennial ryegrass is produced. Whole-plant inoculation and molecular genetic methods will be used to identify and map genetic markers associated with resistance to the stem rust pathogen. The identification and development of mapping and marker tools will enable the selection of perennial ryegrass germplasm with resistance to stem rust. Another form of stress that seriously impacts the quality and utility of grasslands is the presence weeds that can out-compete the agricultural crop for limited resources. Soil application of live pseudomonads which produce a previously identified bioherbicide will tested in two different environments to determine its ability reduce the germination of grassy weeds in field trials.

Last Modified: 10/24/2014
Footer Content Back to Top of Page