National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, 54874, South Korea.
National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, 54874, South Korea; Jeongup-si Agricultural Technology Center, Jeongup, 56141, South Korea.
Biochem Biophys Res Commun. 2020 Dec 17;533(4):1385-1392. doi: 10.1016/j.bbrc.2020.10.027. Epub 2020 Oct 20.
Rice is a particularly widely consumed food crop globally, but its yield is seriously damaged by bacterial blight due to Xanthomonas oryzae pv. oryzae (Xoo) and bakanae disease due to Fusarium fujikuroi (F. fujikuroi). However, broad-spectrum resistance (BSR) to both Xoo and F. fujikuroi remains largely elusive. In this study, we showed that rice monothiol glutaredoxin GRXS15 localizes in mitochondria and the nucleus, and its transcription is induced by Xoo. Transgenic rice lines constitutively expressing OsGRXS15 showed enhanced disease resistance to Xoo and F. fujikuroi, while CRISPR/Cas9-based knockout mutants showed reduced resistance compared with the wild-type plants. The transcription of pathogenesis-related (PR) genes was significantly induced in OsGRXS15-expressing plants. The rice transcription factor OsWRKY65 was identified as a binding partner, and it directly interacted with OsGRXS15 in the nucleus. Moreover, we revealed that the interaction of OsGRXS15 and OsWRKY65 results in the upregulation of OsPR1. These results suggested that OsGRXS15 interacts with transcription factors, and it confers BSR through regulating the expression of genes related to pathogen response. This is the first report on the nuclear function associated with the monothiol glutaredoxin GRXS15.
水稻是全球范围内一种特别广泛消费的粮食作物，但由于稻黄单胞菌（Xanthomonas oryzae pv. oryzae，Xoo）引起的细菌性条斑病和由藤仓镰刀菌（Fusarium fujikuroi，F. fujikuroi）引起的恶苗病，其产量严重受损。然而，对 Xoo 和 F. fujikuroi 的广谱抗性（BSR）仍然难以实现。在本研究中，我们表明水稻单硫醇谷胱甘肽还原酶 GRXS15 定位于线粒体和细胞核中，其转录受 Xoo 诱导。过表达 OsGRXS15 的转基因水稻品系对 Xoo 和 F. fujikuroi 表现出增强的抗病性，而基于 CRISPR/Cas9 的敲除突变体与野生型植物相比表现出降低的抗性。OsGRXS15 表达植物中病程相关（PR）基因的转录显著诱导。鉴定出水稻转录因子 OsWRKY65 是一个结合伴侣，它在核内与 OsGRXS15 直接相互作用。此外，我们揭示了 OsGRXS15 和 OsWRKY65 的相互作用导致 OsPR1 的上调。这些结果表明 OsGRXS15 与转录因子相互作用，并通过调节与病原体反应相关的基因表达来赋予 BSR。这是关于单硫醇谷胱甘肽还原酶 GRXS15 与核功能相关的首次报道。
