Fig. 2

Infectivity of SMV recovered from the pSC3, pSC3-MCS, or pSC3-YFP clones in soybean plants. a Symptoms of pSC3, pSC3-MCS, and pSC3-YFP-infected soybean leaves at 7 days post-inoculation (dpi). b Symptoms of pSC3-YFP-infected soybean leaves were observed under normal light (left) or the laser light that excites the yellow fluorescence of YFP at 7 dpi. The wild type SC3 strains were inoculated as control. c Detection of viral RNAs coding for CP and YFP by RT-PCR (above) and Western blotting analysis (below). The plants infected with SC3, pSC3-YFP were tested, and healthy plants were used as a negative control. Gm-β -tubulin was tested as a reference gene. d Detection of SMV accumulation by DAS-ELISA assay. The plants infected with pSC3, pSC3-MCS, pSC3-YFP were tested, and 9 samples were taken from each type. Healthy plants were used as a negative control. The value of P/N (OD405nm) represents OD value of sample/OD value of negative control and the asterisk indicates P-value between groups. **P ≤ 0.05; ***P ≤ 0.01. e Western blotting detects the accumulation of SMV coat protein in soybean plants inoculated with pSC3, pSC3-MCS, pSC3-YFP, and wild type (WT) SMV-SC3. Actin (NCBI, Accession number: AW350943.1) is used as a loading control. The expected size of SMV CP is 31.4 kDa, and the size of actin is 43 kDa