Background

Rice black-streaked dwarf virus (RBSDV) causes one of the most important rice virus diseases of plants in East Asia. However, molecular mechanism(s)controlling rice resistance to infection is largely unknown.

Results

In this paper, we showed that RBSDV infection in rice significantly induced nitric oxide (NO) production. This finding was further validated through a genetic approach using a RBSDV susceptible (Nipponbare) and a RBSDV resistant (15HPO187) cultivar. The production of endogenous NO was muchhigher in the 15HPO187 plants, leading to a much lower RBSDV disease incidence. Pharmacological studies showed that the applications of NO-releasingcompounds (i.e., sodium nitroprusside [SNP] and nitrosoglutathione [GSNO]) to rice plants reduced RBSDV disease incidence. After RBSDV infection, the levels of OsICS1, OsPR1b and OsWRKY 45 transcripts were significantly up-regulated by NO in Nipponbare. The increased salicylic acid contents were also observed. After the SNP treatment, protein S-nitrosylation in rice plants was also increased, suggesting that the NO-triggered resistance to RBSDV infection was partially mediated at the post-translational level. Although Osnia2 mutant rice produced less endogenous NO after RBSDV inoculation and showed a higher RBSDV disease incidence, its RBSDV susceptibility could be reduced by SNP treatment.

Conclusions

Collectively, our genetic and molecular evidence revealed that endogenous NO was a vital signal responsible for rice resistance to RBSDV infection.

中文翻译：

---

一氧化氮可增强水稻对水稻黑纹矮化病毒感染的抵抗力。

背景

水稻黑纹矮化病毒（RBSDV）是东亚植物最重要的水稻病毒病之一。然而，控制水稻对感染的抗性的分子机制在很大程度上是未知的。

结果

在本文中，我们表明水稻RBSDV感染显着诱导了一氧化氮（NO）的产生。通过使用RBSDV易感（Nipponbare）和RBSDV抗性（15HPO187）品种的遗传方法进一步证实了这一发现。15HPO187植物中内源性NO的产生要高得多，从而导致RBSDV疾病发病率低得多。药理研究表明，将NO释放化合物（即硝普钠[SNP]和亚硝基谷胱甘肽[GSNO]）用于水稻植株可降低RBSDV的发病率。RBSDV感染后，OsICS1，OsPR1b和OsWRKY 45的水平在日本晴中，NO显着上调了转录本。还观察到水杨酸含量增加。SNP处理后，水稻植株中的蛋白质S-亚硝基化也增加了，这表明NO触发的RBSDV感染抗性在翻译后水平上部分介导。尽管Osnia2突变水稻接种RBSDV后产生的内源NO较少，并且显示出较高的RBSDV疾病发生率，但通过SNP处理可以降低其RBSDV易感性。

结论

总体而言，我们的遗传和分子证据表明，内源性NO是导致水稻对RBSDV感染产生抗性的重要信号。