BRCC - Restricting the pathogenic effect on barley of the endophytic fungus Ramularia collo-cygni

The Danish Council for Strategic Research – Grant: DKK 15.171.566

Project period: 01.01.2014 – 31.12.2018.

Project description

Scientific summary

Ramularia collo-cygni (Rcc) is an infectious fungus of cereals and grasses that for unknown reasons, develops from an asymptomatic endophyte into a major pathogen of barley. The fast spreading, competitive and asymptomatic nature of Rcc during its endophytic stage represents a genuine challenge to cereal breeders and the deployment of plant protection products. No cultivars with very high expression of resistance have been identified, and no efficient diagnosis predicting a damaging attack exists.

In Denmark, Ramularia leaf spot (RLS) has been recognized as a major disease since 2002, and is scored by the official variety testing system, while in the UK resistance ratings are required for variety recommendation.

We aim to identify the timing, and key molecular and genetic components responsible for the switch from endophytic to pathogenic life style of Rcc, and to use these for the development of tools for barley breeding and for efficient disease diagnosis.

Our hypothesis is that barley can be bred to keep Rcc in its endophytic, non-symptomatic phase, and thereby yield losses due to RLS can be avoided.

By employing molecular, genetic and biological knowledge, reliable markers for breeding and for diagnosis of disease progression will be designed. We will

1. phenotype barley varieties for their response to Rcc;
2. combine genomic, transcriptomic and proteomic analyses to identify key molecular determinants for the plant-Rcc association;
3. understand and define the events leading to the switch in Rcc lifestyles; and
4. design markers for breeding of barley cultivars suppressing RLS disease symptoms due to infection with Rcc.

BRCC brings together, for the first time, leading international groups in the field into a team to integrate the knowledge on the partners i.e. the plant and the microbe.