Submitted to: Potato Association of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/1999
Publication Date: N/A
Technical Abstract: Suberin is a protective biopolymer that is deposited on phellem cell walls of potato tubers during growth and wound-healing. Although suberin is know to be composed of complex polyphenolic and polyaliphatic domains, little is know about the biochemistry initiating and integrating the accumulation of these two domains. Earlier, we demonstrated the importance of these two domains by showing that deposition of the polyphenolic domain alone conferred resistance to infection by bacterial pathogens causing soft rot. However, resistance to fungal pathogens causing dry rot did not appear until after suberin polyaliphatic deposition. We have histochemically monitored the deposition of the two suberin domains during tuber wound-healing and we have adapted a simple method to chromatographically fingerprint suberin aliphatic accumulations in native periderm and developing wound periderm. These results, together with corresponding inhibitor studies and previous research, show that suberin phenolic deposition is histochemically detectable on wound-healing cell walls well in advance of suberin aliphatic deposition. However, unincorporated suberin aliphatic material is chromatographically detectable within the periderm before it begins to accumulate in suberizing cell walls. Several inhibition of suberin polyphenolic deposition were tested and the results indicate that suberin polyaliphatic deposition is coupled to the preceding polyphenolic deposition. These results are important in determining how suberization processes are initiated and integrated in potato tuber to prevent disease.