Parasitic molecular cues during plant-plant interaction - recognition and influence on host plants
Plant Cell and Developmental Biology
Final Report Abstract
In this project, we investigated the molecular dialogue during the interaction between parasitic plants of the genus Cuscuta spp. and host plants. Works related to resistant interactions like Cuscuta reflexa with cultivated tomato are published. In projects which focus on susceptible interactions we used RNAseq to check for transcriptome changes that occur in host plants after treatment with a crude Cuscuta extract and the detection of a C. reflexa glycine-rich protein (CrGRP) that has been identified as a ligand and defense trigger for tomato Cuscuta recptor 1 (CuRe1). Of major interest, however, was the finding and identification of new Cuscuta derived molecular cues that induce host gene expression and consequently initiate and regulate susceptibility and related developmental processes. By using the RNAseq data mentioned above and also by literature search, we selected host genes that are strongly upregulated within the first 48 hours after Cuscuta attachment. Promoters of about 20 genes have been designated and cloned to control the expression of a luciferase reporter gene (prom:luc constructs). The prom:luc constructs have been then used for either transient expression in Nicotiana benthamiana or for stable transformation of Arabidopsis thaliana which both resemble susceptible host plants. Leaf pieces of those plants were then used in a 96-well plate based bioassay to monitor luciferase expression as light over time (up to 24 h) after treatment with different Cuscuta extracts. At least three prom:luc constructs were responsive to Cuscuta molecular cues present in extracts of the parasitic plant and induced clear gene induction. Different Cuscuta extracts were prepared and purified in diverse chromatographic steps that were adapted and improved accordingly. Finally, we succeeded in finding a small, 1-2 kDa non-proteinaceaous compound, that triggered gene-expression of three host marker genes. Yet, the detailed structure and biological function of this Cuscuta molecule is unknown and remains to be deciphered.
Publications
- “Mechanisms of resistance and virulence in parasitic plant– host interactions” (2020), Plant physiology 185 (4), 1282-1291
M Albert, MJ Axtell, MP Timko
(See online at https://doi.org/10.1093/plphys/kiaa064) - “Quinones shuffling the CARDs” (2020), Nature Plants 6 (9), 1074-1075
M Körner, P Slaby, M Albert
(See online at https://doi.org/10.1038/s41477-020-0742-z) - “The tomato receptor CuRe1 senses a cell wall protein to identify Cuscuta as a pathogen” (2020), Nature communications 11 (1), 1-7
V Hegenauer, P Slaby, M Körner, JA Bruckmüller, R Burggraf, I Albert, ... M Albert
(See online at https://doi.org/10.1038/s41467-020-19147-4) - “A cell wall-localized glycine-rich protein of dodder acts as pathogen-associated molecular pattern” (2021), Communicative & integrative biology 14 (1), 111-114
P Slaby, M Körner, M Albert
(See online at https://doi.org/10.1080/19420889.2021.1918369)
