The interplay of suppressive soil bacteria and plant root exudates determines germination of microsclerotia of .

Unlabelled: Dormant microsclerotia play a vital role in the survival and spread of , as they can stay viable in the soil and maintain their infectivity for many years. In our previous work, we revealed that soil bacterial volatiles are a key inhibitory factor causing microsclerotia dormancy in the soil. In this study, we further demonstrate that root exudates collected from both host and non-host plants can effectively rescue microsclerotia from bacterial suppression and initiate germination.

The soil bacterial community regulates germination of Plasmodiophora brassicae resting spores rather than root exudates.

Clubroot, caused by Plasmodiophora brassicae, is a severe soil-borne disease that restricts the production of cruciferous crops worldwide. A better understanding of biotic and abiotic factors regulating germination of P. brassicae resting spores in the soil is significant for developing novel control methods.

Dormancy and germination of microsclerotia of are regulated by soil bacteria and soil moisture levels but not by nutrients.

The soil-borne pathogen infects roots of its host plant, oilseed rape, and systemically colonizes stems where it finally forms microsclerotia at crop maturity. Once returned to the soil after harvest, microsclerotia undergo a stage of dormancy, in which they may survive for several years. Since there is neither efficient chemical control nor effective resistance in oilseed rape cultivars to control the disease, alternative control strategies may consist in regulating the germination and dormancy of microsclerotia in the soil.