Feeding behavior of <i>Myzus persicae</i> on mock-inoculated, JI- or JIΔP2-infected turnip plants.

(a) Symptoms on turnip leaves at 14 dpi. From left to right, mock-inoculated, JI-infected, JIΔP2-infected leaf. (b) Western blot analysis of the accumulation of P2 (18 kDa), P4 (37, 44 kDa) and P6-TAV (62 kDa) in JI- or JIΔP2-infected turnip plants at 14 dpi. Each lane corresponds to a total protein extract from a different plant. The large RuBisCO subunit is stained by Ponceau S and serves as a loading control. Mock is extract from a mock-inoculated healthy leaf. (c-d) The behavior of individual aphids was recorded by electrical penetration graph (EPG) for 8 h on turnip leaves infected or not with the indicated virus (N = 21–24). Selected EPG parameters are presented sorted according to (c) duration or (d) occurrence. The histogram bars display means and standard errors. Different letters indicate significant differences between plant infection status as tested by GLM (generalized linear model) followed by pairwise comparisons using “emmeans” (p 2 = 7.776, p = 0.020) but no differences for the total duration of stylet penetration (GLM, Df = 2, χ2 = 3.868, p = 0.145), the total duration of pathway phase (GLM, Df = 2, χ2 = 4.037, p = 0.133) and the time to first sap ingestion from phloem (Cox, Df = 2, χ2 = 0.373 p = 0.185). Statistical analysis of the occurrence of events revealed significant differences for the numbers of stylet penetrations, pathway phases and intracellular test punctures on infected (JI and JIΔP2) vs mock-inoculated plants (GLM, Df = 2, χ2 = 10.756; χ2 = 24.948; χ2 = 37.13, p 2 = 35.958, p < 0.001).