Project description:H. seropedicae is a diazotrophic and endophytic bacterium that associates with economically important grasses promoting plant growth and increasing productivity. To identify genes related to bacterial ability to colonize and promote plant growth wheat seedlings growing hydroponically in Hoaglandâs medium were inoculated with H. seropedicae the bacteria and incubated for 3 days. mRNA from the bacteria present in the root surface and in the plant medium were purified, depleted from rRNA and used for RNA-seq profiling. RT-qPCR analyses were conducted to confirm regulation of selected genes. Comparison of RNA profile of bacteria attached to the root and planktonic revealed an extensive metabolic adaptation to the epiphytic life style.
Project description:Endophytic bacteria influence plant growth and development and therefore are an attractive resource for applications in agriculture. However, little is known about the impact of these microorganisms on secondary metabolite (SM) production by medicinal plants. Here we assessed, for the first time, the effects of root endophytic bacteria on the modulation of SMs in the medicinal plant Lithospermum officinale (Boraginaceae family), with a focus on the naphthoquinones alkannin/shikonin (A/S). The study was conducted using a newly developed in vitro system as well as in the greenhouse. Targeted and non-targeted metabolomics approaches were used and supported by expression analysis of the gene PGT, encoding a key enzyme in the A/S biosynthesis pathway. Three bacterial strains, Chitinophaga sp. R-73072, Xanthomonas sp. R-73098 and Pseudomonas sp. R-71838 induced a significant increase of diverse SMs, including A/S, in L. officinale in both systems, demonstrating the strength of our approach for screening A/S derivative-inducing bacteria. Our results highlight the impact of root-endophytic bacteria on secondary metabolism in plants and indicate that production of A/S derivatives in planta likely involves cross-modulation of different metabolic pathways that can be manipulated by bacterial endophytes.