Ipomoea genus comprises of more than 600 species distributed worldwide which are either noxious agricultural weeds or an important crop species. Characteristic traits of Ipomoea sp such as its unique mating system of selfing without significant inbreeding depression, doubling genetic transmission and evolving genes by natural selection has positioned itself as a model genus for understanding ecological shifts. Ipomea sps exhibits natural tolerance to glyphosate and demonstrate the ability to re-grow following glyphosate damage. The rate of glyphosate tolerance varies widely within this species. The current study employs a metabolomics approach to track the metabolic perturbations caused by glyphosate application in I. lacunosa to understand the differences in physiological adaptability across various glyphosate tolerance levels.
Results/Conclusions
Profiling of polar metabolites in the leaves of more tolerant biotype (WAS) and a less tolerant biotype (QUI) biotypes of pitted morningglories (Ipomoea lacunosa) highlighted innate metabolic variances and similarities between the two biotypes. Shikimic acid accumulated in both the biotypes indicating glyphosate toxicity but interestingly it was accompanied by a decrease in sugars and polyols and an increase in most amino acids, which is an indication of recovery and regeneration. The potential limiting factor for evolving higher tolerance to chemical stress is the associated fitness cost. Results for our metabolomics study provide evidence that shifts in the metabolic adaptations in Ipomoea biotypes provides varying tolerance and adaptability to chemical stress and thus could possibly evolve a rigid ‘ecological defense’ strategies that minimizes fitness cost associated with increasing tolerance. The physiological alterations observed in these morningglories might help them to quickly acclimatize to various chemical stresses and thus would prove to be difficult parameter in agricultural management strategies.