TABLE 1

Root exudate chemistry of switchgrassa

Compound groupIdentified compound(s)Concentration ± SD (µM)
AlcoholMethanol2.654 ± 0.629
Amino acid/sugarAlanine, glycine, lysine, valine, betaine, methylamine, trimethylamine6.144 ± 11.126
CarbohydrateArabinose, fructose, glucose77.589 ± 51.494
KetoneAcetone12.083 ± 7.789
Nucleic acidThymine, thymidine, uracil1.939 ± 3.657
Organic acidAcetate, acetoacetate, allantoin, benzoate, formate, gallate, lactate, succinate, tartrate13.169 ± 22.014
QuinoneQuinone2.947 ± 3.291
  • a Exudate samples were collected from switchgrass seedlings grown hydroponically under sterile conditions. Plant growth medium was snap-frozen on liquid nitrogen, freeze-dried, and sent to the Pacific Northwest National Lab Environmental Molecular Sciences Laboratory for analysis. Exudate chemistry was determined by collection of 1D nuclear magnetic resonance (NMR) spectra for each sample following standard Chenomx (Edmonton, Alberta, Canada) sample preparation and data collection guidelines (81). Samples were analyzed on a Varian Direct Drive (VNMRS) spectrometer (Agilent Technologies, Santa Clara, CA) equipped with a Varian triple resonance salt-tolerant cold probe with a cold carbon preamplifier and a Dell Precision T3500 Linux workstation running VNMRJ 3.2.