Fig. 2

Selection of the optimal method to induce transgenic hairy roots and the process of hairy roots development using the PCI method. a Representative pictures of transgenic hairy roots development of three methods. Bar:5 cm b Transgenic hairy roots screening using GFP fluorescence under microscope. Bar:5 mm c RT-PCR analysis of the transgenic hairy roots for confirming the integration and expression of GFP reporter gene. d and e represent the regeneration rate for inducing hairy roots using three methods and the percentage of transgenic hairy roots induced using three methods respectively. The Histogram represent data from six independent experiments (25–60 replicates per condition in each method), The letters represent significant differences at p < 0.05 according to the LSD multiple comparisons test in different treatments. f K599 was collected from screening medium and injected into injected into the cotyledon-node. g Callus was induced at 6–14 day after injection and the root primordium was established. h The hairy roots were induced at the injection site and grew densely at about 14–28 days after injection. i Cut the original roots and infected with M.incognita