Overexpression of MdNup62 reduces high-temperature resistance
Because MdNup62 was induced by high temperature, we investigated the high-temperature resistance function of MdNup62 . OE-MdNup62 Arabidopsis lines were subjected to a high-temperature (45°C) treatment (Figure 4a). Additionally, the survival rate of transgenic Arabidopsis was significantly lower than that of WT (Figure 4b). We also performed a qRT-PCR analysis of A. thaliana HSPs (AtHSP101 , AtHSP22-ER , AtHSP21.0 , andAtHSP70T-2 ) (Figure 4c). Their expression levels in transgenic Arabidopsis were reduced under high-temperature conditions. Consistently, after the heat treatment, the ROS accumulation in leaves was clear greater in OE-MdNup62 lines compared with WT (Figure 5a). In addition, the malondialdehyde and H2O2 levels were significantly greater than in WT (Figure 5b, c). Moreover, the superoxide dismutase, peroxidase, and catalase activities were lower in OE-MdNup62lines than in WT (Figure 5d–f). High-temperature resistance assays were carried out in transgenic tomato plants (Figure 6a). As in transgenicA. thaliana , the survival rate of transgenic tomato was significantly reduced compared with WT (Figure 6b). The presence of the transgene in OE-MdNup62lines was confirmed by genomic PCR, and qRT-PCR (Figure 6c,d). The expression levels of HSPs (HSP101 , HSP22-ER ,HSP21.0 , and HSP70T-2 ) in transgenic tomato were significantly reduced under high-temperature conditions compared with under normal growth conditions (Figure 6e). These results indicate thatMdNup62 reduces plant high-temperature resistance.