PLANT PHYSIOLOGY , Vol 104, Issue 2 527-533, Copyright © 1994 by American Society of Plant Biologists
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DEVELOPMENT AND GROWTH REGULATION |
Following Suberization in Potato Wound Periderm by Histochemical and Solid-State 13C Nuclear Magnetic Resonance Methods
R. E. Stark, W. Sohn, R. A. Pacchiano Jr, M. Al-Bashir and J. R. Garbow
Department of Chemistry, College of Staten Island and the Graduate School of the City University of New York, 2800 Victory Boulevard, Staten Island, New York 10314 (R.E.S., W.S., R.A.P., M.A.-B)
The time course of suberization in wound periderm from potato (Solanum
tuberosum L.) has been monitored by histochemical and high-resolution
solid-state nuclear magnetic resonance (NMR) methods. Light microscopy
conducted after selective staining of the lipid and double-bonded
constituents shows that suberin is deposited at the outermost intact
cell-wall surface during the first 7 d of wound healing; suberization forms
a barrier to tissue infiltration at later times. Cross polarization-magic
angle spinning 13C NMR spectra demonstrate the deposition of a polyester
containing all major suberin functional groups after just 4 d of wound
healing. Initially the suberin includes a large proportion of aromatic
groups and fairly short aliphatic chains, but the spectral data demonstrate
the growing dominance of long-chain species during the period 7 to 14 d
after wounding. The results of preliminary 13C-labeling experiments with
sodium [2-13C]acetate and DL-[1-13C]phenylalanine provide an excellent
prospectus for future NMR-based studies of suberin biosynthesis.
