GENE SPECIFICITY IS MAINTAINED IN TRANSIENT EXPRESSION ASSAYS WITH PROTOPLASTS DERIVED FROM DIFFERENT TISSUES OF BARLEY

In some cereal species that are still recalcitrant to stable transform ation and regeneration, transient expression in isolated protoplasts i s a useful tool for the study of gene expression and regulation. We ha ve successfully applied these techniques to barley protoplasts derived from developing endosperm, aleurone, leaves and roots in order to cha racterize functionally cis-acting motives in two gene promoters, corre sponding to trypsin inhibitorBTI-CMe and to sucrose synthase Ss1. Gene specificity is maintained in transient expression assays with protopl asts isolated from these different barley tissues and the pattern of e xpression parallels the mRNA levels observed for the corresponding gen es in the same tissues.