Differential oilseed crop lipid accumulation through inoculation with Pseudomonas fluorescens LBUM677: rhizosphere competency, genetic determinants and species-specific variations
J. JIMÉNEZ BECERRA (1), M. Filion (2), A. Novinscak (2) (1) Université de Moncton, Canada; (2) Université de Moncton, Canada

Pseudomonas spp. have been widely studied for their plant growth promoting effect. However, their capacity at specifically promoting lipid accumulation in oilseed crops is not well characterized. In this study, we evaluated the effect of Pseudomonas fluorescens LBUM677 at promoting lipid accumulation in three oilseed crops: soy (Glycine max), canola (Brassica napus) and corn gromwell (Buglossoides arvensis), a plant of high nutraceutical interest for its unusual seed accumulation of omega-3 stearidonic acid. Pots experiments were conducted under growth chamber conditions. Seeds were either inoculated or not at sowing using LBUM677 and plants were harvested at 4, 8 and 12 weeks. A molecular marker specific to LBUM677 was also developed following a rep-PCR screening of a large collection of P. fluorescens strains and used in qPCR assays to correlate LBUM677 soil rhizosphere competency to seed lipid accumulation. Total oil seed content and fatty acid composition was analyzed at seed maturity using gas chromatography. Although LBUM677 was able to establish itself in the rhizosphere of the three plant species at similar levels, it differentially increased plant biomass, total oil content and lipid composition in a plant specific-manner. Sequencing of LBUM677 genome using the PacBio RS II technology revealed genetic elements likely involved in plant growth promotion and seed lipid accumulation. Validation of their specific role is presently ongoing.

Abstract Number: P3-72
Session Type: Poster