DEVELOPMENTAL ANALYSIS OF ELONGATION FACTOR-1-ALPHA EXPRESSION IN TRANSGENIC TOBACCO

The developmental regulation of the translational elongation factor EF-1-alpha has been analyzed in tobacco. A gene fusion was constructed consisting of the 5' and 3' regions of the tomato genomic clone LeEF-A from the EF-1-alpha gene family and the beta-glucuronidase coding region. Analysis of the transgenic plants containing this chimeric gene demonstrated that the tomato LeEF-A flanking sequences were sufficient to confer expression patterns similar to those of the endogenous tobacco EF-1-alpha gene. The patterns of beta-glucuronidase activity in this system indicated that during plant growth and development EF-1-alpha is regulated with increased expression corresponding to regions of high protein synthesis, including meristems, rapidly growing tissues, and developing gametophytes. In addition, EF-1-alpha expression responds rapidly to changes in growth patterns induced by hormone treatment. Our results are in agreement with studies in animals indicating that EF-1-alpha expression may be rate limiting for protein synthesis and demonstrate that the analysis of EF-1-alpha is of value for studying interrelationships between protein synthesis and developmental control.