Virus-induced gene silencing of <i>TtPDS</i> causes photobleaching in leaves and flowers of <i>Thalictrum thalictroides</i>.

<p><b>A: Flower and leaf </b><b><i>TtPDS</i></b><b> silencing phenotypes compared to controls.</b> Ai: Untreated flower of <i>T. thalictroides</i>, note green leaflets and green/yellow floral center; Aii: TRV2-<i>TPDS</i> treated plant, showing partial photobleaching of leaflets that appear variegated; Aiii: Detail of varying degrees of photobleaching in leaflets; Aiv: Detail of untreated flower, note that carpels and young stamens are normally photosynthetic (green); Av: Detail of treated flower showing silencing in stamens and carpels, three older stamens are not photobleached and therefore look green (asterisks), a patch of necrotic tissue (a viral effect) is indicated with an arrow; Avi: empty TRV2 mock-control flower showing background viral effects: arrow points to reduced sepal with patch of necrotic tissue. Scale bar = 1 mm. <b>B: Comparative expression of </b><b><i>TtPDS</i></b><b> in leaves and flowers of </b><b><i>T. thalictroides</i></b><b> plants treated with TRV2-</b><b><i>TPDS</i></b><b>, relative to controls.</b> Untreated and mock-treated (empty TRV2) plants are compared to TRV2-<i>TPDS</i> treated plants showing photobleached leaves (left panels) or flowers (right panels). Reverse-transcriptase PCR was performed with locus-specific primers to the housekeeping gene <i>TtACTIN</i> (loading control), to endogenous <i>TtPDS</i> and to the viral transcripts TRV1/TRV2. For TRV2: larger band results from the presence of insert, smaller band from an empty TRV2 (mock control).