Fig. 8

Effect of GmMAX3b overexpression and GmMAX3b knockdown in hairy roots on soybean nodulation. Chimerical soybean plants were generated by transformation with K599 harboring, GmMAX3b-overexpression (GmMAX3b-OE), GmMAX3b-knockdown (GmMAX3b-KD) or GUS vector. Plants with wild-type shoots and transgenic hairy roots were inoculated with Bradyrhizobium japonicum strain USDA110. Nodule numbers from the hairy roots were counted and the roots were sampled for gene expression analysis at 28 days post inoculation. a Chimerical soybean plants with wild-type shoots but transgenic hairy roots. GmMAX3b-OE plants developed more nodules as compared with GUS control. b qRT-PCR confirmation of GmMAX3b-OE and GmMAX3b-KD in transgenic hairy roots as compared to GUS control. c Hairy root fresh weight (g) and nodule numbers ratio in GmMAX3b-OE, GmMAX3b-KD and GUS control lines. d Expression levels of nodulation genes in GmMAX3b-OE, GmMAX3b-KD and GUS transgenic hairy roots as control. e Validation of SL biosynthesis and signaling genes in GmMAX3b-OE, GmMAX3b-KD and GUS as control hairy root lines. Gene expression was determined by qRT-PCR with GmACTIN as an internal control. Data are expressed as means ± s.d. from at least 3 independent experiments with biological replicates. Differences were analyzed, *p < 0.05; **p < 0.01 in student’s t-test