The Influence of Wild Grapevine Endophytes on the Growth of the Model Plant Arabidopsis thaliana (L.) Heynh

We have evaluated the growth characteristics of the model plant Arabidopsis thaliana after inoculation of A. thaliana seeds with the most common endophytes of wild grapevine Vitis amurensis Rupr., namely bacteria Rhizobium (syn. Agrobacterium) sp., Bacillus velezensis, Curtobacterium sp, Erwinia sp., Gordonia aichiensis, Pantoea sp., Pseudomonas sp., Sphingomonas sp., Xanthomonas sp., and the fungi Biscogniauxia sp., Cladosporium sp., Didymella sp., Exobasidium sp., Penicillium sp., Pestalotiopsis sp, and Xylaria sp. A positive effect on plant growth was observed in A. thaliana following seed inoculation with endophytic fungi (Xylaria sp., Didymella sp., and Exobasidium sp.) and bacteria (Gordonia aichiensis and Sphingomonas sp.). The inoculation with the fungi Xylaria sp., Didymella sp., Exobasidium sp., and Penicillium sp. significantly increased seed production in A. thaliana by 2.5–5-fold. The analysis of the phytohormone-regulating gene transcription in A. thaliana plants following inoculation with the grapevine endophytic microorganisms suggests that plant growth was enhanced through transcriptional changes in individual genes of hormone biosynthetic pathways. Consequently, endophytic bacteria and fungi from V. amurensis may serve as potential natural growth stimulators for agricultural plants.