Figure 6

Reduced nodule formation in transgenic hairy roots expressing amiRNAs for GmWRP1, GmExo70J7 and GmExo70J9.

(A) Expression analysis of GmWRP1 in silenced plants. Expression of GmExo70J7 and GmExo70J9 was performed by qRT-PCR using a soybean actin gene as control. The results shown are from five individual empty BPMV vector control plants (amiR-0) and GmWRP1, GmExo70J7 or GmExo70J9-silenced plants (amiR-target). The asterisks indicate that the GmWRP1, GmExo70J7 and GmExo70J9 transcript levels in silenced plants are significantly different from those in control plants (t test, P = 0.01). (B) Reduced nodule formation in silenced plants. The fresh root weight and nodule number for each plant were determined from representative control plants (amiR-0) and silenced plants each for GmWRP1 (amiR-WRP1), GmExo70J7 (amiR-Exo70J7) and GmExo70J9 (amiR-Exo70J9) to calculate the number of nodules per gram of fresh root weight. According to Duncan’s multiple range test (P = 0.01), means do not differ significantly if they are indicated with the same letter. The pictures of root nodules collected 5 weeks after inoculation from a representative plant for each gene are also shown.