New insights into interactions of roses and pathogenic fungi and crosstalk potential of various stress signalling pathways

H.S. Domes, T. Debener
The responses of plants to attacks by pathogenic fungi are controlled by a complex network of different signaling pathways. The successful recognition of the pathogen and the resulting signal processing up to the expression of the required defence genes can lead to resistant plants. This project deals with the interaction between roses and the fungal pathogens Diplocarpon rosae and Podosphaera pannosa, causing rose black spot disease and powdery mildew, respectively. This allows the comparison of infection strategies and differences caused by the different fungal lifestyle. So far, the resistance mechanisms and signaling pathways used are not fully known. Another complicating aspect is the fact that these signal transduction networks are susceptible to interference. It is not only the pathogen itself that specifically manipulates signaling pathways through effector proteins, but also abiotic environmental conditions that can influence them. This can have both positive and negative effects on the plant's defence response. Here we take a closer look at the influence of phosphate deficiency. Via qRT-PCR the expression of five phosphate starvation induced (PSI) genes was analysed for different treatments. These data were collected, together with controls, in three independent biological replicates and are available at three points in time. We found an interesting downregulation of the PSI genes in leaves infected with P. pannosa compared to controls and D. rosae infections. Between roses that are either resistant or susceptible to D. rosae, however, only few significant changes were observed. This could be a first indication of a role of the phosphate signaling pathway during infection with the pathogenic fungus P. pannosa and a possible link of abiotic and biotic stress response pathways.
Domes, H.S. and Debener, T. (2020). New insights into interactions of roses and pathogenic fungi and crosstalk potential of various stress signalling pathways. Acta Hortic. 1283, 89-96
DOI: 10.17660/ActaHortic.2020.1283.13
roses, powdery mildew, black spot, defence response, phosphate starvation, signaling, crosstalk

Acta Horticulturae