Overexpression of AtSOAR1 affected drought tolerance related genes expression of alfalfa
To explore the potential mechanisms of overexpression of AtSOAR1improving drought tolerance in alfalfa, we detected expression of drought tolerance and also ABA signaling transduction related genes in WT and TG plants. The results showed that expression of ABA receptorsMsPYL5 and MsPYL6 was significantly down regulated in the TG lines compared to that of the WT plant. Expression of MsSnRK2.3 and MsPYL7was significantly up-regulated in TG2, and MsSnRK2.3 andMsMYC2 were highly expressed in TG3. The ABA-dependent drought response gene MsABF1 and the ABA-independent drought response genes MsCBF1 and MsCBF4 showed up-regulated expression byAtSOAR1. Expression of MsMYB2 was down-regulated inAtSOAR1 transgenic plants (Figure 8). The results suggestedAtSOAR1 inhibited ABA signaling transduction by repressing ABA receptor MsPYL5 and MsPYL6 , and regulated the ABA-dependent and ABA-independent pathways to improve alfalfa drought tolerance.