Objective:
Using Arabidopsis and Mentha meristems as experimental materials 1)Determine frequency of plasmodesmata between cell layers of the meristematic region. 2)Determine if significant ultrastructural changes occur in frequency and structure of plasmodesmata as a result of plasmolytic or cryoprotective events. 3)Determine ultrastructure of meristematic regions exposed to and recovering from cryoprotective treatments. These data will be combined to determine the nature and extent of observable damage during the cryopreservation process. We will attempt to identify critical steps that minimize damage and improve recovery after liquid nitrogen exposure.

Approach:
In this SCA we will do a detailed ultrastructural examination of Arabidopsis and Mentha meristems using the transmission electron microscopes available at Colorado State University. Arabidopsis and Mentha serve as ideal study systems for the proposed studies. The availability of DNA sequence and cDNA expression technologies for Arabidopsis will be critical as these studies progress. Robust cryopreservation techniques are available for Mentha, which has served as a model system in many of our preliminary microscopic studies. The results from these two systems can be applied to many vegetatively propagated materials within the National Plant Germplasm System.