在水稻中跨物种表达一种昆虫内源性 microRNA 增强了对二化螟的抗性。

Trans-kingdom expression of an insect endogenous microRNA in rice enhances resistance to striped stem borer Chilo suppressalis.

机构信息

National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Wuhan, China.

College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.

出版信息

Pest Manag Sci. 2022 Feb;78(2):770-777. doi: 10.1002/ps.6690. Epub 2021 Nov 17.

DOI:10.1002/ps.6690

PMID:34704657

Abstract

BACKGROUND

The striped stem borer (SSB), Chilo suppressalis Walker, is a major pest of rice worldwide. Breeding of transgenic rice expressing Bacillus thuringiensis (Bt) toxins is a powerful strategy to control SSB. However, pests may evolve certain resistance to Bt toxins in transgenic plants. Hence, new controlling strategies must be continuously developed.

RESULTS

We successfully generated SSB-resistant rice (csu-53) expressing the artificial microRNA (amiRNA) of SSB endogenous miRNA (csu-novel-miR53) through the RNAi-based technology. Feeding assays demonstrated that csu-53 rice inhibited larval growth, delayed pupation time, and reduced pupal weight and eclosion rate of SSB larva. In a 10-day feeding experiment, the miRNA mimic of csu-novel-miR53 also suppressed larval growth and more importantly increased larval mortality. Transcriptome analysis identified 28 differentially expressed unigenes (DEGs) in the midgut between SSB larvae fed on csu-53 rice and the wild type. One DEG (DN90065_c0_g12) validated by qRT-PCR had a predicted target site of csu-novel-miR53. In addition, in vitro double-stranded RNA synthesis and further feeding assay proved that DN90065_c0_g12 is most likely the target of csu-novel-miR53.

CONCLUSION

amiRNA-mediated strategy can be applied to the development of insect-resistant crops, and the novel amiRNA csu-novel-miR53 of SSB has important application potential in developing SSB resistant rice. © 2021 Society of Chemical Industry.

摘要

背景

条纹稻纵卷叶螟（SSB）是一种世界性的水稻主要害虫。培育表达苏云金芽孢杆菌（Bt）毒素的转基因水稻是控制 SSB 的一种有力策略。然而，害虫可能会在转基因植物中进化出对 Bt 毒素的某些抗性。因此，必须不断开发新的控制策略。

结果

我们成功地通过基于 RNAi 的技术培育出了表达 SSB 内源性 miRNA（csu-novel-miR53）的人工 microRNA（amiRNA）的 SSB 抗性水稻（csu-53）。喂养实验表明，csu-53 水稻抑制幼虫生长，延迟化蛹时间，并降低 SSB 幼虫的蛹重和羽化率。在 10 天的喂养实验中，csu-novel-miR53 的 miRNA 模拟物也抑制了幼虫的生长，更重要的是增加了幼虫的死亡率。转录组分析在 SSB 幼虫取食 csu-53 水稻和野生型水稻的中肠中鉴定出 28 个差异表达的 unigenes（DEGs）。通过 qRT-PCR 验证的一个 DEG（DN90065_c0_g12）具有 csu-novel-miR53 的预测靶标位点。此外，体外双链 RNA 合成和进一步的喂养实验证明，DN90065_c0_g12 很可能是 csu-novel-miR53 的靶标。