OsAP79 has no antibacterial activity and confers no cold tolerance
Previous studies have reported that AP genes have antimicrobial and abiotic effects (Figueiredo et al ., 2021). To further explore this, NIP, OE, and knockout lines were used in Xanthomonas oryzaepv. oryzicola (Xoc ) and Xanthomonas oryzae pv.oryzae (Xoo ) infestation and cold tolerance treatments. The lesion lengths of OE79-9, OE79-12, CR79-11, and CR79-18 lines afterXoc infestation were 22.4, 17.7, 22.7, and 29.8 mm, respectively, and it was 20 mm for NIP (Figure S9a and S9c). Meanwhile, the average lesion lengths of the NIP, OE79-9, OE79-12, CR79-11, and CR79-18 lines after Xooinfestation were 6.8, 7.3, 8.0, 7.8, and 6.8 cm, respectively (Figure S9b and S9d). No significant differences were detected among the different genotypic lines for bacterial leaf streak (BLS) or bacterial leaf blight (BLB) resistance tests. These results suggest thatOsAP79 is not associated with BLS or BLB resistance in rice.
To investigate the cold tolerance of OsAP79 in rice, NIP, OE, and knockout lines were treated at 5 °C for 5 days, and recovered at room temperature (25 °C) for 7 days. All lines grew normally, without deaths, and their survival rates were more than 90%. No significant differences were detected among the genotypic lines. These results indicate thatOsAP79 did not play an important role in cold tolerance (Figure S10a and S10b).