|Detail of the metabolite profile
|Description for analysis method
||Trichomes were first extracted with 2.0 mL 80% MeOH (containing 18µg/mL of umbelliferone as internal standard) in H2O. The samples were agitated for 2 hr and centrifuged for 30 min at 2900g. The 1.0 mL of the resulted extract was dried with speed vacuum and redesolved in 200 ?L 80% CH3OH. A portion of 5 ?L was injected onto a reverse column (ACQUITY UPLC™ BEH C18 1.7µm, 2.1 mm x 150mm), which was maintained at 60 °C and components were eluted using a linear gradient from 95% to 30% A (eluent A, 0.1% aq. HOAc) over 30 min and at a flow rate 0.56 mL/min. The complimentary eluent B was acetonitrile. TOF-MS spectra were acquired under the following conditions: spectral acquisition rate: 3.13 per second; detector voltage: 2600 (v); threshold: 2037; ESI: -4500 v; desolvation temperature: 300 oC; nebulizer pressure: 350 kPa; interface: 100 oC. Accurate mass was achieved within 20 ppm.
The chromatograms obtained from UPLC- qTOF-MS analysis were deconvoluted and aligned within mass and retention time windows prior to normalization using the Waters MarkerLynx 4.1 software (Waters) to generate a matrix of m/z and retention pairs with associated intensities resulting in a metabolite marker list. The data of mass peak intensities were collected using the following parameters: mass tolerance was set at 0.05 Da, noise elimination level at 5.00, minimum peak intensity at 40, retention time window at 0.2.
|Species / Cultivar / Tissue
||Medicago sativa / leaf hopper resistance line, Forage Genetics International / Trichome
|Description for biological material
||Trichomes were collected from stems of alfalfa plants and pooled together as one replicate for both metabolome and transcriptome experiments. After the first replicate samples were collected, the plants were cut back and grow for 2 weeks. Trichomes collected from these plants were the second replicate samples. And the 3rd replicates samples were collected from the cutting back of the 2nd replicate plants. The semi-quantification will be based on the amount of 150 mg F.W. trichomes isolated from stems. After shearing off trichomes, stems were simultaneously collected as a control for metabolite profiling.
||Don Sik Yang, Lloyd W. Sumner. Metabolic Profiling of trichomes from Potato Leafhopper susceptible and resistant alfalfa lines. (unpublished)
Plant Biology Division
The Samuel Roberts NOBLE Foundation, Inc.
Ardmore, OKLAHOMA, U.S.A - 73401.