Transcriptional analysis of the interaction between the oomycete biocontrol agent, Pythium oligandrum, and the roots of Vitis vinifera L.
Résumé
The oomycete, Pythium oligandrum, has received considerable attention as a potential biocontrol agent against various pathogenic fungi of plants, including grapevine. However, much remains underexplored on the interaction between grapevine and P. oligandrum. In the present study, following root colonization with P. oligandrum, grape-genome microarray analyses showed significant changes in the grapevine root transcriptome. The main changes concerned the genes involved in the biological processes and cellular functions, more particularly those associated with response to stimuli. Several functional categories were differentially expressed in P. oligandrum-inoculated plants. The highest inductions concerned the functional categories involved in secondary metabolism (terpenoid and flavonoid pathways), abscisic acid metabolism, resistance genes and some RNA regulation transcription factors. Redox state functional category was, however, significantly repressed. Whereas the expression of several transcripts would suggest that the plant sets up defense systems against the oomycete, certain similarities with symbiotic microorganism/root interactions were also observed, the main one being the stimulation of subtilases. These data provide new insights about the pathways involved in the establishment of the complex relationship between P. oligandrum, an oomycete with biocontrol potential, and grapevine.