3.5 Transient overexpression of PpINH1 in peach fruit inhibits VIN activity
A pBI121-PpINH1 overexpression construct was introduced into peach fruit via Agrobacterium tumefaciens -mediated injection (Figure 4a, b ). As shown in Figure 4c , GUS staining shows that pBI121-PpINH1 was successfully transferred into peach fruit and is expressed. Compared with the control, expression of PpINH1 increased 47-fold, 29-fold, 11-fold, and 27-fold at 24, 36, 48, and 72h after injection, respectively (Figure 4d ).
VIN activity in peach fruit overexpressing PpINH1 decreased over the first 36 h after injection, then recovered almost to initial levels over the remaining 48 h, although VIN activity remained significantly below that of controls at each time point. VIN activity in control peach fruit (injected with Agrobacterium tumefaciens containing the empty pBI121 vector), increased throughout the 72 h experiment (Figure 4e ).