Li Bei, Sun Shengyuan, Gao Xianmin, Wu Mengxiao, Deng Yong, Zhang Qinglu, Li Xianghua, Xiao Jinghua, Ke Yinggen, Wang Shiping
National Key Laboratory of Crop Genetic Improvement, National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China.
Rice (N Y). 2019 Jul 16;12(1):51. doi: 10.1186/s12284-019-0315-9.
Rice (Oryza sativa) feeds half of the world's population. Rice grain yield and quality which are constrained by diseases and mineral nutritions have important human healthy impacts. Plant "fruit-weight 2.2-like" (FWL) genes play key roles in modulating plant fruit weight, organ size and iron distribution. Previous work has uncovered that the grains of OsFWL5-oeverexpressing rice accumulated more beneficial element zinc (Zn) and less toxic element cadmium (Cd) content. However, whether FWL genes play roles in rice resistance remains unknown.
Here, we validated that one of rice FWL genes OsFWL5 plays a positive role in defense to Xanthomonas oryzae pv. oryzae (Xoo). Overexpresion of OsFWL5 promotes HO accumulation and cell death. The OsFWL5-overexpresing plants show activated flg22-induced reactive oxygen species (ROS) generation, and increased resistance to Xoo, indicating that OsFWL5 functions to increase pathogen-associated molecular pattern (PAMP)-triggered immunity in rice. The activated defense response is associated with increased the expression of genes involved in jasmonic acid (JA)-related signaling. Furthermore, Cd can induce rice resistance to Xoo, and OsFWL5 is required for Cd-induced rice defense response.
Putting our finds and previous work together, OsFWL5 could be a candiate gene for breeders to genetically improve rice resistance and grain quality.
水稻养活了世界上一半的人口。受疾病和矿物质营养限制的水稻产量和品质对人类健康有着重要影响。植物“果实重量2.2样”（FWL）基因在调节植物果实重量、器官大小和铁分布方面发挥着关键作用。先前的研究发现，过表达OsFWL5的水稻籽粒积累了更多有益元素锌（Zn），而有毒元素镉（Cd）的含量则更低。然而，FWL基因是否在水稻抗性中发挥作用尚不清楚。
在此，我们验证了水稻FWL基因之一OsFWL5在防御水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae，Xoo）方面发挥着积极作用。OsFWL5的过表达促进了H2O2的积累和细胞死亡。过表达OsFWL5的植株表现出flg22诱导的活性氧（ROS）生成被激活，并且对Xoo的抗性增强，这表明OsFWL5在增强水稻中病原体相关分子模式（PAMP）触发的免疫方面发挥作用。激活的防御反应与茉莉酸（JA）相关信号通路中相关基因表达的增加有关。此外，镉可以诱导水稻对Xoo的抗性，而Cd诱导的水稻防御反应需要OsFWL5。
综合我们的研究结果和先前的工作，OsFWL5可能是育种者在基因上改良水稻抗性和籽粒品质的一个候选基因。
