Figure 5.

PTGS transmission from L1 roots to 6b4 scions and PTGS-induced DNA methylation in 6b4 do not require any RdDM component in L1. (A) GUS siRNA accumulation and GUS activity in scion leaves of plants of the indicated genotypes grown under short day conditions for eight weeks after grafting. RNA was extracted from a bulk of four plants for small RNA gel blots, and ethidium bromide staining is shown as loading control. GUS activity is expressed as fluorescent units per minute per microgram of total proteins quantified by Bradford. Averages and standard deviations correspond to the number of plants indicated in Table 1. (B) Percentage of DNA methylation at representative CHH and CHG sites in the 5′ and 3′ regions of the GUS coding sequence in scion leaves of plants of the indicated genotypes grown under short day conditions for 8 weeks after grafting. Analyses were performed at HaeIII-49, MspI-126, HaeIII-1467 and MspI-1529 restriction sites (see Supplementary Figure S2). The percentage of DNA methylation was calculated as described in Figure 1D. Mean and standard deviation bars are based on two biological replicates.