DIVERGENCE AND DIFFERENTIAL EXPRESSION OF ACTIN GENE FAMILIES IN HIGHER-PLANTS

This chapter describes the diversity and differential expression of plant actin gene families and proteins. The plant actins are encoded by ancient and divergent classes of genes that may not have shared a common actin gene ancestor since the evolution of early vascular plants. The encoded actin proteins show remarkable sequence and charged residue variability within any single plant. The number of assorted roles proposed for plant actins in various cell processes and cell types, this complex gene family is required to meet the demands for actin regulation and/or novel actin protein function. The correlation of diverse actin genes and proteins with numerous proposed actin functions and the demonstration of a required role for actin in these processes are yet to be explored. Isolation or construction of plant actin mutants provides the critical proof of function for individual classes of actins. Analysis of plant actin gene sequences suggests that they contain extremely diverse protein isovariants. © 1991, Elsevier Science & Technology. All rights reserved.