Plant Pathology and Crop Protection

Verticillum in oilseeed rape

Host plant sensing in Verticillium longisporum during early stages of interaction with Brassica napus through root exudates and its role in disease initiation

The rapeseed (Brassica napus) oil has a significant economic value, which lead to an almost progressively increasing demand in Germany since the mid-1980s. Brassica oil crops are considerably vulnerable to fungal infections. One of the economically most important pathogenic fungus, causing severe damage to B. napus, is the ascomycete Verticillium longisporum. Flowering onset appears to be a critical developmental stage for V. longisporum to colonize rapeseed plants. Until today, it is not clearly understood how the physiological changes in the plant affect root-pathogen interactions.

The plant root system, in all its complexity including root signal exchange with soil borne microbes and other roots, is yet not well studied. Plant roots are estimated to release about 5-20% of their photosynthetically-fixed carbon into the soil (rhizodeposition) offering a good environment for rhizosphere microorganisms to grow. A number of root-specific metabolites were suggested to exhibit a protective function against pathogens and pests as they showed activity against bacteria, fungi, nematodes and herbivores. Microorganisms are capable of affecting root systems in general, such as stimulating rhizodeposition and increasing exudate turnover rates. So far, only few reports about root exudates, and the interactions in which they are involved, exist. In addition, many questions still need to be addressed about V. longisporum and its germination. Therefore, it is aimed in this project to take a closer look into the B. napus - V. longisporum interaction in relation to root exudates at different physiological stages of the plant.

 

References:

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  • Zhou, L.; Hu, Q.; Johansson, A.; Dixelius, C. (2006): Verticillium longisporum and V. dahliae: infection and disease in Brassica napus. In Plant Pathology 55 (1), pp. 137–144. DOI: 10.1111/j.1365-3059.2005.01311.x.

Investigator: Rania Saleh

Supervisor: Prof Andreas von Tiedemann

Project Start: January 2015

Duration: 3 Years

 

RS 02/2015