2.1 Materials
The sorghum wildtype and transgenic line pSbUbi:schl-qsuB #48
(variety Wheatland) used in this study have been described
previously.26 The plants were grown at the University
of California (UC) greenhouse Oxford facility and harvested at full
maturity without the panicles.26 Each sample consisted
of stem and leaf biomass from five plants, which was dried in an oven at
50 °C for five days and ground using a Model 4 Wiley Mill equipped with
a 1-mm mesh (Thomas Scientific, Swedesboro, NJ). Chemicals for DES
synthesis, including choline chloride and 3,4-dihydroxybenzoic acid,
were purchased from JT Baker and BeanTown Chemical, respectively. The
chemical used as the third constituent of the DES (ethylene glycol) was
purchased from VWR. Cellulase, enzyme blend Cellic CTec2, sodium acetate
trihydrate, and sodium azide were purchased from Sigma-Aldrich. The
enzyme was stored at 2-8 °C.