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.

稻米是全球范围内消费特别广泛的粮食作物，但稻米黄单胞菌（Xanthomonas oryzae pv）会导致细菌性疫病严重破坏稻米的单产。米曲霉（白叶枯病）和恶苗病由于枯萎恶苗（F.苗病菌）。但是，对Xoo和F.kujikuroi的广谱抗药性（BSR）仍然难以捉摸。在这项研究中，我们表明水稻单硫醇谷胱甘肽毒素GRXS15定位于线粒体和细胞核，其转录是由Xoo诱导的。组成型表达OsGRXS15的转基因水稻系显示出对Xoo和F. fujikuroi，而基于CRISPR / Cas9的敲除突变体与野生型植物相比显示出降低的抗性。在表达OsGRXS15的植物中显着诱导了与病程相关（PR）基因的转录。水稻转录因子OsWRKY65被鉴定为结合伴侣，并直接与细胞核中的OsGRXS15相互作用。此外，我们发现，OsGRXS15和OsWRKY65的相互作用导致的上调OsPR1。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的表达赋予BSR。这是关于与单硫醇戊二糖GRXS15相关的核功能的首次报道。