Effect of intracellular localization and codon modification on accumulation of SAG1. (A) SAG1 accumulation in tobacco leaves. The SAG1 band intensity expressed from E. coli and detected by Western blot was estimated to build a quantization calibration curve with amount standards. The leaf-expressed SAG1 band intensity detected by western blot was estimated using "Gel-Pro analyzer" and compared with the quantification calibration curve; a = p < 0.05: KnS vs. PVXS and AS, AS vs. KoS, and AnS vs. AoS; b = p < 0.01: PVXS vs. KoS; c = p < 0.001: AnS vs. KoS, and KnS vs. AoS and KoS. FW: fresh weight, M, molecular weight marker pre strained (Fermenta); (B) Relative amounts of SAG1 transcripts. SAG1 transcript levels were normalized with the actin transcripts used as an internal control using "Gel-Pro analyzer". Statistical analysis was performed by one-way analysis of variance (ANOVA) using the Newman-Keuls Multiple Comparison Test.