Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 29, 2003
Publication Date: December 29, 2003
Citation: Aekyung, L., J.-K., S., Roh, M.S., Slovin, J.P. 2003. Dehydration intolerant seeds of ardisia species accumulate storage and stress proteins during development.. Journal of the American Society for Horticultural Science.
Interpretive Summary: The seeds of two commercially marketable small shrubs, Ardisia crenata and Ardisia japonica do not germinate if they are stored for more than a few weeks in conditions where they are allowed to dehydrate. This makes it difficult to mass-produce these plants, which have attractive white or red berries that can stay on the plant for over a year. We have performed biochemical experiments to determine whether Ardisia seeds contain certain types of proteins that are believed to protect seeds against dehydration. Other types of seeds that you can dry down and sell in packets make these types of proteins. We found that Ardisia seeds do make these protective proteins, and that the somewhat less dehydration sensitive Ardisia crenata seeds make more of them than Ardisia japonica seeds, which do not germinate at all after two weeks of drying at room temperature. Surprisingly, we also found that Ardisia crenata makes these proteins as early as when the berries are first starting to grow, which is unlike what is found in seeds that are tolerant to drying out, where these proteins are made much later in development. The complicated patterns of when, and how much of these proteins accumulate may be telling us something about the mechanism by which plant cells can dehydrate and still remain alive. This information is useful to scientists working to understand how plants tolerate dehydration, to horticulturalists working to commercialize species that are not dehydration tolerant, and scientists interested in long term storage of recalcitrant seed in botanical or germplasm collections
The seeds of two commercially marketable small shrubs, Ardisia crenata and Ardisia japonica do not germinate if they are stored for more than a few weeks in conditions where they are allowed to dehydrate, and can therefore be classified as recalcitrant. The berries of these plants remain attached for long periods of time after an approximately 34 week period of development. The proteins in developing seeds, germinating seeds, and seeds stored for various periods of time in moist or dry conditions and at 10'C or 25'C were examined by polyacrylamide gel electrophoresis and immunoblot analysis with antibodies to dehydrin and oleosin. Both dehydrin- and oleosin-like proteins were detected in early stages of seed development, as were proteins that are likely to function as seed storage proteins. Storage of seeds in dry conditions induced the expression of both dehydrin- and oleosin-like proteins, but only later in the 8 week storage period. The levels of these proteins were considerably less in the less dehydration tolerant A. japonica. The accumulation patterns for these proteins indicate that the developmental program that allows for dehydration tolerant seeds to undergo maturation and drying in the final stages of development is uncoupled in the recalcitrant Ardisia seed.