Lu Rongfei, Liu Zhiyang, Shao Yudong, Su Jiuchang, Li Xuejuan, Sun Feng, Zhang Yihua, Li Shuo, Zhang Yali, Cui Jin, Zhou Yijun, Shen Wenbiao, Zhou Tong
Key Laboratory of Food Quality and Safety, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu Province, China.
College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Rice (N Y). 2020 Apr 14;13(1):24. doi: 10.1186/s12284-020-00382-8.
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.
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.
Collectively, our genetic and molecular evidence revealed that endogenous NO was a vital signal responsible for rice resistance to RBSDV infection.
水稻黑条矮缩病毒（RBSDV）引发了东亚地区最重要的水稻病毒病之一。然而，控制水稻对该病毒感染抗性的分子机制在很大程度上尚不清楚。
在本文中，我们表明水稻感染RBSDV会显著诱导一氧化氮（NO）的产生。通过使用对RBSDV敏感的品种（日本晴）和对RBSDV抗性的品种（15HPO187）进行遗传学方法进一步验证了这一发现。15HPO187植株中内源性NO的产生量要高得多，导致RBSDV发病率低得多。药理学研究表明，向水稻植株施用释放NO的化合物（即硝普钠[SNP]和亚硝基谷胱甘肽[GSNO]）可降低RBSDV发病率。RBSDV感染后，日本晴中OsICS1、OsPR1b和OsWRKY 45转录本的水平被NO显著上调。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，这表明NO触发的对RBSDV感染的抗性在翻译后水平上部分介导。尽管Osnia2突变水稻在接种RBSDV后产生的内源性NO较少，且表现出较高的RBSDV发病率，但其对RBSDV的易感性可通过SNP处理降低。
总体而言，我们的遗传和分子证据表明内源性NO是水稻对RBSDV感染抗性的重要信号。
