Author
Weller, David | |
YANG, MING MING - Northwest Agricultural & Forestry University | |
KWAK, YOUN-SIG - Gyeongsang National University | |
MAVRODI, OLGA - Washington State University | |
MAVRODI, DMITRI - University Of Southern Mississippi | |
PIETERSE, CORNE - Utrecht University | |
BAKKER, PETER - Utrecht University | |
Thomashow, Linda |
Submitted to: International PGPR Workshop
Publication Type: Abstract Only Publication Acceptance Date: 4/1/2015 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Root pathogens are major impediments to grain production worldwide and must be controlled in order to significantly increase food production needed to feed >9 billion people by 2050. In the Pacific Northwest of the USA, wheat is grown under a wide range of climatic conditions. Two broad-spectrum antibiotics, phenazine-1-carboxylic acid and 2,4-diacetylphloroglucinol (DAPG), produced in the rhizosphere by indigenous PGPR belonging to the “Pseudomonas fluorescens group,” provide protection against root pathogens in wheat and barley fields. Take-all, caused by Gaeumannomyces graminis var. tritici, is the most important root disease of wheat grown under high precipitation and irrigation. A natural suppression of take-all known as take-all decline (TAD) develops because of the buildup of DAPG producing-P. brassicacearum during wheat or barley monoculture. It is estimated that 800,000 hectares of Northwest wheat benefit to some extent from protection by DAPG produced on roots. Growers across the USA use TAD to manage take-all. Even after decades of exposure to DAPG during wheat monoculture, G. graminis var. tritici has not developed resistance because the antibiotic attacks several basic cellular processes. Wheat cultivars were shown to differentially respond to TAD, giving growers a means to increase the level of take-all suppression. DAPG, P. brassicacearum and TAD soil induced systemic resistance in Arabidopsis thaliana against P.syringae pv. tomato but DAPG-minus mutants and pasteurized soil failed to induce resistance. DAPG-producing PGPR are critical to the root health of small grains and other crops, and may play a role in protecting crops against foliar diseases. |