Plant & Animal Genome VI Conference

W53

ISOLATION AND TRANSIENT EXPRESSION OF A STRONG CONSTITUTIVE PROMOTER FROM SUGARCANE

1. USDA ARS, Aiea, HI 96701
2. University of Hawaii, Honolulu, HI 96701

Expression of five polyubiquitin cDNA clones from sugarcane has been characterized. The corresponding five genes were grouped into four sub-families, based on hybridization and sequence analysis. RNA gel-blot analysis with gene-specific probes revealed that steady-state mRNA pools for each sub-family were approximately equal in all tested tissues, however the different sub-families differed significantly in expression levels. One sub-family, represented by cDNA clones scubi241 and scubi511 was expressed at the highest level. Additionally, the sub-families differed in induction by heat stress, with three sub-families substantially induced (approximately ten-fold) while the scubi241/511 sub-family was only marginally induced. Two genomic clones homlogous to the scubi241/511 cDNAs have been isolated and sequenced. Promoter and first intron sequences from these two genes were found to be sufficient to drive high levels of transient expression from a GUS reporter gene in sugarcane suspension culture cells and tobacco leaves.