Phytohormone production by the arbuscular mycorrhizal fungus Rhizophagus irregularis
Fig 2
GA4 detection in multiple reactions monitoring (MRM) mode.
(A) Structure and fragmentation pattern of GA4. (B) UPLC-MRM-MS chromatogram of GA4 in negative mode. Top (blue lines): External standard (30 nM) of GA4. Middle (red lines): pre-purified SPE fraction from 250,000 ground spores of R. irregularis. Bottom (purple lines): pre-purified SPE fraction from 250,000 ground spores of R. irregularis spiked with GA4 standard to a final concentration of 30 nM. Plain lines are for m/z transition 331 > 213. Dashed lines are for m/z transition 331 > 257. Signal intensities are displayed in counts per second (cps).