Molecular cloning and characterization of an actindepolymerizing factor gene in Hevea brasiliensis

Abstract

Actin-depolymerizing factor (ADF) plays important roles in regulating actin dynamics by maintaining the optimum equilibrium between unpolymerized actin molecules and assembled actin filaments in different cellular processes. In this study, the first ADF gene in Hevea brasiliensis designated as HbADF, was isolated. The HbADF contained an open reading frame (ORF) encoding 139 amino acids. The deduced HbADF showed high identities to plants ADF proteins. Besides a conserved ADF domain, HbADF also contained putative actin and specific F-actin binding sites, phosphorylation site and possible CAM (calmodulin) combining region. The phylogenetic analysis indicated that HbADF was clustered in the subclass I. Being consistent with  phylogenetic result, the expression of HbADF was constitutive. The HbADF transcripts were upregulated by ethephon and wounding treatments; whereas, HbADF was firstly induced, and then gradually downregulated by jasmonic acid. The expression profiles and characterizations of HbADF suggested that HbADF might be  associated with latex regeneration and flow in H. brasiliensis.

Key words: Actin cytoskeleton, actin-depolymerizing factor, expression analysis, Hevea brasiliensis, semiquantitative reverse-transcription polymerase chain reaction.