Characterization of actin-gene family members and their expression during development in witchweed (Striga asiatica...

Partial cDNAs and genomic fragments representing three different actin genes of witchweed (Striga asiatica L. Kuntze) have been isolated using the polymerase chain reaction. The three genes differ in nucleotide sequence within their coding and 3' non-coding regions but encode proteins identical over the regions where sequence is available. Southern blot hybridization analysis of total genomic DNA showed that the three actin genes belong to a multigene family. Expression studies using gene-specific probes showed that transcripts of each of the three Striga actin genes were present at comparable levels in roots, shoots, and 24-h-induced haustoria. The relative abundance of the three transcripts within roots or shoots, however, differed appreciably. Such differences in transcript accumulation within organs indicate that differences might exist in their cell- or tissue-specific mode of regulation.