“Comparative Metabolomics Reveals a Species-Specific Accumulation of Ascarosides in Nematodes”

Project Summary:

Nematodes, also known as roundworms, are one of the world’s most abundant organisms in the soil and profoundly impact global crop production. Chemical signaling plays a central role in establishing plant-nematode interactions; however, the identity of signaling molecules and their underlying mechanisms are largely unknown. Recent studies have suggested that nematodes mediate its interactions with plants by using ascarosides, an evolutionarily conserved family of pheromones. Interestingly, each nematode species in the soil produces their own set of ascarosides to mediate their interactions with plants. Therefore, we proposed to study how plants differentiate between parasitic and non-parasitic nematodes by profiling ascarosides. To address this proposal, we performed mass spectrometric analysis of three parasitic species of nematodes, Meloidogyne incognita, Pratylenchus neglectus, and Heterodera glycines, or root-knot nematode, lesion nematode, and soybean cyst nematode, respectively, and compared with a non-plant-parasitic nematode, Caenorhabditis elegans.

Through analysis of the mass spectrometry results, we found that the nematode species display differential ratios of ascarosides or even the absence of some of them. For instance, ascarosides such as ascr#3 and ascr#7 as well as modified ascarosides such as icas#9 and icas#10 were only detected in the non-parasitic nematode species. Furthermore, the parasitic nematode P. neglectus produced more of some ascarosides such as ascr#9 and ascr#18 than the non-parasitic nematode C. elegans. These preliminary results suggest disparate accumulation of several ascarosides between parasitic and non-parasitic nematodes. Future research is required to determine whether this differential accumulation of ascarosides is associated with plant recognition of different species of nematodes.

My Experience:

Through this internship at BTI, I learned a lot about biology and chemistry and had the chance to apply what I learned in science classes in a real life setting. The experience of conducting tests such as gel electrophoresis, qPCR, and mass spectrometry was much more meaningful in a lab than reading about it in school. I had never worked in a lab before this internship and the opportunity was very valuable to me in terms of learning new skills and considering a future in scientific research. Everyone I worked with at BTI was helpful and willing to explain even the most basic aspects of plant research and it was a great environment in which to learn. I have enjoyed working at BTI these last few weeks not only because of everything this internship has taught me but also the opportunities it afforded in research and furthering knowledge about plants.