SCHWARZEROVÁ, K., VONDRÁKOVÁ, Zuzana, FISCHER, L., BOŘÍKOVÁ, P., BELLINVIA, E., ELIÁŠOVÁ, Kateřina, HAVELKOVÁ, L., FIŠEROVÁ, J., VÁGNER, Martin, OPATRNÝ, Z. The role of actin isoforms in somatic embryogenesis in Norway spruce. BMC Plant Biology. 2010, 10(89), 1-13. ISSN 1471-2229. E-ISSN 1471-2229

Application of low doses of latrunculin B (lat B) during the maturation of somatic embryos predominantly killed suspensor cells while leaving the cells in meristematic centres alive, indicating differential sensitivity of actin in the two cell types. The treatment resulted in faster development of advanced embryos into mature somatic embryos and elimination of insufficiently developed ones. We analysed the composition of actin isoforms in the culture and isolated four spruce actin genes. Analysis of their expression during embryo maturation revealed that one actin isoform was expressed constitutively in both cell types, whereas three actin isoforms were expressed predominantly in suspensor cells and their expression declined during the maturation. The expression decline was enhanced by Lat B treatment. Sequence analysis revealed amino-acid substitutions in the Lat B-binding site in one of the suspensor-specific actin isoforms, which may result in a different binding affinity for Lat B.