Project description:As the phyllosphere is a resource-limited niche, microbes have evolved different survival strategies by collaborating or competing with other organisms. This leads to the establishment of network structures which are stabilised by so-called microbial hub organisms. An already identified hub in the Arabidopsis thaliana phyllosphere is the oomycete pathogen Albugo laibachii. From wild Arabidopsis plants with white rust symptoms we isolated the basidiomycete yeast Moesziomyces albugensis, which is closely related to plant pathogenic smut fungi. It suppresses the infection of A. laibachii in lab experiments and inhibits growth of several bacterial phyllosphere members. The transcriptomic response of M. albugensis to presence of A. laibachii and bacterial SynCom members was investigated by using RNA sequencing. Interestingly, several genes encoding secretory proteins, mostly glycoside hydrolases and peptidases, are particularly induced upon interaction with A. laibachii.
Project description:We conducted field surveys to detect the population density of the most important invasive weed species and their associated virus vectoring aphids in crops grown under high input (HIF) vs low-input (LIF) field conditions, with and without fertilizers and pesticides. The most frequent invasive weed species were Stenactis annua, Erigeron canadensis and Solidago canadensis. These species were hosts predominantly for the aphids Brachycaudus helichrysi and Aulacorthum solani in both management systems. The 13% higher coverage of S. annua under LIF conditions resulted in a 30% higher B. helichrysi abundance and ~85% higher A. solani abundance compared with HIF conditions. To reveal virus infection in crop plants and invasive weeds high-throughput sequencing of small RNAs were carried out. Bioinformatics analysis of the results detected the presence of 16 important plant viruses, but not resulting strikingly different pattern under LIF and HIF. This could suggest that invasive weeds serves as a virus reservoir both under low and high input management systems. The lake of any management increases virus vector aphids abundances, their presence has a great impact on the viromes of the crops.
