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ARS Home » Plains Area » Lincoln, Nebraska » Wheat, Sorghum and Forage Research » Research » Research Project #427095

Research Project: The Impacts of Lignin Modification on Resistance to Stem Rust and Sawfly Fungal in Wheat

Location: Wheat, Sorghum and Forage Research

Project Number: 3042-21000-033-11-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 1, 2014
End Date: Jul 31, 2019

Stem Rust (Puccinia graminis) and sawflies (Cephus cinctus) are emerging threats to wheat production in the Great Plains region. Previously, lignin biosynthesis has been implicated in plant resistance to both insects and fungal pathogens. Little effective natural sawfly resistance exists in wheat. Stem rust resistance genes are numerous, but all are eventually overcome by the pathogen. New sources of resistance to both pests are needed. Altered lignin biosynthesis could be used to increase the resistance of wheat to these threats. Specific objectives: 1. Develop transgenic wheat lines overexpressing genes in lignin biosynthesis. 2. Examine resistance to stem rust and sawfly in the overexpression lines.

To increase lignin synthesis wheat, we will introduce three constitutive expression cassettes under control of the 35S promoter. We will constitutively express the genes encoding 3 enzymes in the monolignol pathway: caffeoyl CoA O-methyltransferase, coumarate 3-hydroxylase, 4-coumarate-CoA ligase, in Chinese spring wheat CB037. Agrobacterium-mediated transformation will be used coupled to npt II selectable marker. For each transgenic cassette a minimum of 10 independent events will be generated. Transgenic lines will be evaluated for resistance to stem rust and sawflies in greenhouse environments. Successful transformation events will be transferred to winter wheats via traditional breeding approaches.