Abstract
Isolated mesophyll cells of zinnia (Zinnia elegans) can be trans-differentiate to tracheary elements (TEs). For the purpose of analysis of zinnia genes, we have developed an electroporation-based method for introduction of plasmid DNA into the zinnia cells. Here we examined the usefulness of the double-stranded RNA (dsRNA)-mediated silencing approach using the method. A decrease in number of GFP-expressing cells was observed after co-introduction of P35S::GFP plasmid and dsRNA corresponding to GFPmRNA, suggesting that RNA silencing is functional in the zinnia system. Therefore we next investigated the effect of dsRNAs corresponding to endogenous mRNAs of cellulose synthase-encoding genes on TE differentiation. When the cells had been electroporated with the dsRNAs whose target mRNAs were shown to accumulate during TE morphogenesis, the rates of abnormal TEs/total TEs reached more than 20%. This work may provide a valuable tool for functional analysis of TE differentiation-related zinnia genes.
