Expression patterns of GmBTB/POZ in Phytophthora sojae‐resistant and P. sojae‐susceptible soybean cultivars. (A) The tissue‐specific expression patterns of GmBTB/POZ in resistant cultivar ‘Suinong 10’ and susceptible cultivar ‘Dongnong 50’ under normal conditions. (B) Relative expression of GmBTB/POZ in soybean cultivars ‘Suinong 10’ and ‘Dongnong 50’ on P. sojae infection. The infected samples were collected at 0, 1, 3, 6, 9, 12, 24, 36 and 48 h after P. sojae infection. The relative expression levels of GmBTB/POZ were compared with those of mock‐treated plants (plants treated with sterile water) at the same time point. Fourteen‐day‐old soybean plants were used for analysis. The housekeeping gene of soybean GmEF1 (NM_001248778) was used as an internal control to normalize the data. The experiment was performed on three biological replicates, each with three technical replicates, and was statistically analysed using Student’s t‐test (*P < 0.05, **P < 0.01). Bars indicate the standard error of the mean.