Transient GUS expression from non-replicating and replicating viral vectors in cell suspensions and leaves. (A) Non-replicating vectors contained the GUS-intron gene downstream of a conventional TEV 5’UTR (pGPTVK-GI) or a modified CPMV 5’ UTR (pEAQ-GUS). The latter vector provided P19 as a second expression cassette on a single T-DNA. Values represent the mean ± SD of samples from three co-cultures or four infiltrated leaves. (B) The replication-competent vector pBY031-I1 and pPSP19 were co-delivered to N. benthamiana leaves together (−REP) or with a third binary vector containing the Bean yellow dwarf virus DNA replicase gene (+REP). Values represent the mean ± SD of samples from seven leaf infiltrations on different leaves. Means on the same axis labeled with the same Greek letter are not different from each other at the 95% significance level.