In plants, development takes place continuously from activities of small groups of pluripotent cells known as meristems. The entire above ground portion of a plant develops from continuous events in a meristem found in the shoot apex, the shoot apical meristem. Since it is not uncommon for many plants to live for a century, the continuous activities in shoot apical meristems describes processes unmatched elsewhere in biology. This study will focus on how molecular events in the meristem function to make a plant. Genes with meristematic enriched expression, designated "meri", will be studied. Expression patterns for specific cDNAs in hand will be confirmed and localized on a tissue specific level. Additional meri clones will be isolated. The transcriptional promoter for the most specific clones will be defined, fused to a reporter gene (GUS) and transferred to Arabidopsis plants. Transgenic plants expressing the chimeric meri-GUS gene will be analyzed for histological expression to confirm localization studies and to determine how the meri genes are expressed in the dynamic events in meristems. Furthermore, the response of the meri genes to physiological cues will be examined by crossing the 'meri-GUS' plants to a transgenic line capable of heat inducible hormone alterations. These studies will provide insight into how genes within the shoot apical meristem function in development, and hence insight into how the meristem "makes" a plant.
