The mechanism and control of desiccation tolerance in seeds
Desiccation tolerance is one of the most outstanding features found in the plant kingdom. Seeds that possess such attribute, the so-called orthodox seeds, can be dried and stored for many years without significant loss of viability. Seeds that lack this characteristic, the so-called recalcitrant seeds, represent a big challenge for those who need to keep them in seed banks for germplasm conservation purposes. In order to gain insight into the theme, we study physiological, cytological and molecular aspects of desiccation sensitivity in seeds of Medicago truncatula, a legume model, orthodox-seeded species. Germinated orthodox seeds can be a useful model system for studies on desiccation sensitivity based on the fact that upon germination, orthodox seeds lose desiccation tolerance progressively and become comparable to the recalcitrant types.
Various mild stresses, such as drying, osmoticum, cold- and heat-shock, and exogenous ABA, have shown to be capable to confer or increase desiccation tolerance on germinated orthodox seeds. It is reasonable to hypothesize that such treatments could have similar effects on recalcitrant seeds, reducing partially their desiccation sensitivity and/or increasing their storability. Previously, we have developed a desiccation tolerance rescuing system in Medicago seeds, which allows studying embryonic cells in their desiccation tolerant and -sensitive states. We are interested in the role of the cytoskeleton in conferring and maintaining desiccation tolerance. In this project we collaborate with the Lab of Plant Cell Biology at WUR.
Loss and reestablishment of desiccation tolerance of germinated seeds