Heterologous overexpression of resveratrol synthase (PcPKS5) gene enhances antifungal and mite aversion by resveratrol accumulation

Huping jujube is widely cultivated in northern China. PcPKS5, a resveratrol synthase (STS) gene, contains all functionally divergent plant specific type III PKSs and is involved in resveratrol synthesis. This study aimed to assess the effects of heterologous overexpression of the resveratrol synthase (PcPKS5) gene on Huping jujube (Ziziphus jujuba Mill.) plant resistance and nutritional quality. Stems with leaves and shoot tips of Huping jujube (Ziziphus jujuba Mill) were infected with agrobacterium expressing PcPKS5 and GUS, and three positive plants were identified. Resveratrol (0.45 μg/g fresh weight) was detected by HPLC in line 2 transgenic plants. Interestingly, 100 μl extract of 1 g/ml transgenic plant crude extract showed an inhibitory effect equivalent to 1.0 μg of pure resveratrol. In addition, transgenic plants displayed increased anti-mite resistance compared with the wild-type counterparts. Importantly, higher PcPKS5 expression levels were found in young tissues compared with the stem and mature leaves. This study also provides a stable genetic transformation mechanism for developing new plant germplasms in Huping jujube.