The novel cyst nematode effector protein 30D08 targets host nuclear functions to alter gene expression in feeding sites

Abstract

Cyst nematodes deliver effector proteins into host cells to manipulate cellular processes and establish a metabolically hyperactive feeding site. The novel 30D08 effector protein is produced in the dorsal gland of parasitic juveniles, but its function has remained unknown. We demonstrate that expression of 30D08 contributes to nematode parasitism, the protein is packaged into secretory granules and it is targeted to the plant nucleus where it interacts with SMU2 (homolog of suppressor of mec-8 and unc-52 2), an auxiliary spliceosomal protein. We show that SMU2 is expressed in feeding sites and an smu2 mutant is less susceptible to nematode infection. In Arabidopsis expressing 30D08 under the SMU2 promoter, several genes were found to be alternatively spliced and the most abundant functional classes represented among differentially expressed genes were involved in RNA processing, transcription and binding, as well as in development, and hormone and secondary metabolism, representing key cellular processes known to be important for feeding site formation. In conclusion, we demonstrated that the 30D08 effector is secreted from the nematode and targeted to the plant nucleus where its interaction with a host auxiliary spliceosomal protein may alter the pre-mRNA splicing and expression of a subset of genes important for feeding site formation.

Plant Proteins and Processes Targeted by Parasitic Nematode Effectors

“…Finally, a H. schachtii effector, Hs30D08, has been shown to interfere with mRNA splicing, thereby altering gene expression in feeding sites (Verma et al, 2018). RNA splicing is required to remove introns from pre-mRNA and to join the protein-coding sequences (exons) together during the translation of mRNA into protein.…”

Suppression of PAMP-triggered immunity (PTI) by effector proteins synthesized by phytopathogens and delivered into cells of infected plant

“…Suppressor of Mec-8 and Unc52 2) funkcjonującym jako białko pomocnicze spliceosomu. Białko 30D08 powoduje zmiany w ekspresji 2180 genów, w tym genów związanych z obróbką, transkrypcją i wiązaniem RNA [77]. Białko efektorowe PsAvh23 z Phytophthora sojae zaburza oddziaływanie podjednostki ADA2 z podjednostką katalityczną GCN5 kompleksu acetylotransferazy histonowej.…”

Modulation of Arabidopsis Flavonol Biosynthesis Genes by Cyst and Root-Knot Nematodes

“…Quantitative RT-PCR was first used to quantify AtMYB12 transcripts in H. schachtii and M. incognita-infected Arabidopsis roots. It must be noted that only one reference gene (Actin 8) was used in qRT-PCR [51] and that small differences in expression observed among the data are subject to potential variations in reference expression [52,53]. H. schachtii appears to induce AtMYB12 expression in Arabidopsis roots between 5-9 dpi.…”