Cell Wall Bound Ferulic Acid in Barley Seedlings during Development and its Photoisomerization.

Only the E-isomer of ferulic acid was detected in alkaline hydrolyzates of cell walls of coleoptiles and primary leaves of etiolated barley seedlings. The levels of E-ferulic acid increased significantly with growth reaching a maximum of 50 μ moles/g dry cell wall. The accumulation started one day later and finished one day later than the increase in dry weight of cell walls. On irradiation of dark grown plants the Z-isomer was produced in cell walls by direct photoisomerization of the E-isomer. The levels of Z-isomer formed did not change during a subsequent 21 hr dark incubation.