FIGURE 2.

Phytophthora sojae effector Avh148 is crucial for pathogen virulence. (a) Expression profile of Avh148 in soybean hairy roots inoculated with P. sojae P6497. Total RNA was extracted from mycelia (MY) or infected soybean roots at the indicated time points, and transcript levels of Avh148 were detected by quantitative real‐time reverse transcription PCR (RT‐qPCR). P. sojae Actin gene was used as an internal control. hpi, hours postinoculation. (b) Analysis of Avh148 expression in soybean hairy roots upon P. sojae infection (n = 10). Hairy roots expressing GFP‐Avh148 or GFP were inoculated with mycelia plugs of red fluorescent protein (RFP)‐labelled P. sojae. Oospore production in infected hair roots was investigated under a fluorescence microscope, and lesion length was determined at 48 hpi. (c) Quantification of P. sojae oospores on soybean hairy roots at 48 hpi. (d) Quantification of P. sojae biomass in soybean hairy roots by quantitative PCR (qPCR). (e) Effect of Avh148 silencing in P. sojae on infection in soybean seedlings (n = 8). Disease symptoms were monitored in aetiolated hypocotyls. Photographs were taken at 7 days postinoculation (dpi). (f) Analysis of relative expression of Avh148 in P. sojae transformants by RT‐qPCR. (g) Analysis of P. sojae biomass in soybean hypocotyls by genomic DNA (gDNA)‐based qPCR. This experiment was performed twice, with similar results. Scale bars: 1 cm in (e), 0.3 mm in (e). Data in (c), (d), (f), and (g) represent mean ± SE of three independent biological replicates. Different letters indicate statistically significant differences among samples (p < .01; Duncan's multiple range test)