Fig. 2
Factors affecting the transient expression efficiency in poplar leaves. Optimization of the experimental parameters was carried out on P. davidiana × bolleana. a Effect of the plant development stage on transient expression efficiency. Syringe agroinfiltration was conducted on leaves LPI 4 using A. tumefaciens GV3101 suspended in modified infiltration medium [10 mM MgCl2, 5 mM MES-KOH (pH 5.6) and 1.6 mM AS] and evaluated at 5 dpi. b Effect of leaf age on transient expression efficiency. The syringe agroinfiltration was conducted on plants PI 11–12 using GV3101 suspended in modified infiltration medium [10 mM MgCl2, 5 mM MES-KOH (pH 5.6) and 1.6 mM AS] and evaluated at 5 dpi. c Effect of Agrobacterium strains on transient expression efficiency. The syringe agroinfiltration was conducted on the leaves LPI 4 of plants PI 11–12 by using the indicated A. tumefaciens strains suspended in modified infiltration medium [10 mM MgCl2, 5 mM MES-KOH (pH 5.6) and 1.6 mM AS] and evaluated at 5 dpi. d Effect of acetosyringone concentration on transient expression efficiency. The syringe agroinfiltration was carried out on leaves LPI 4 of plants PI 11–12 by using GV3101 suspended in the infiltration media [10 mM MgCl2, 5 mM MES-KOH (pH 5.6)] supplemented with different concentrations of AS and evaluated at 5 dpi. e Effect of the duration of transient expression on the transient expression efficiency. The syringe agroinfiltration was carried on leaves LPI 4 of plants PI 11–12 by using GV3101 suspended in modified infiltration medium [10 mM MgCl2, 5 mM MES-KOH (pH 5.6) and 1.6 mM AS]. LUC activity was evaluated at 1, 3, 5, 7, 9, and 11 dpi. The different letters above the bar indicate statistically significant differences, while the same letter indicates no significant difference according to Duncan’s (D) test (P < 0.05). The red line shows the average LUC activity (n = 8)