State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling 712100, Shaanxi, China.
College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China.
Phytopathology. 2024 Oct;114(10):2322-2330. doi: 10.1094/PHYTO-09-23-0330-R. Epub 2024 Oct 4.
The bacterial canker of kiwifruit caused by pv. () is the most devastating disease threatening the global kiwifruit production. This pathogen delivers multiple effector proteins into plant cells to resist plant immune responses and facilitate their survival. Here, we focused on the unique effector HopZ5 in , which previously has been reported to have virulence functions. In this study, our results showed that HopZ5 could cause macroscopic cell death and trigger a serious immune response by agroinfiltration in , along with upregulated expression of immunity-related genes and significant accumulation of reactive oxygen species and callose. Subsequently, we confirmed that HopZ5 interacted with the phosphoserine-binding protein GF14C in both the nonhost plant (NbGF14C) and the host plant kiwifruit (AcGF14C), and silencing of NbGF14C compromised HopZ5-mediated cell death, suggesting that GF14C plays a crucial role in the detection of HopZ5. Further studies showed that overexpression of NbGF14C both markedly reduced the infection of and in , and overexpression of AcGF14C significantly enhanced the resistance of kiwifruit against , indicating that GF14C positively regulates plant immunity. Collectively, our results revealed that the virulence effector HopZ5 could be recognized by plants and interact with GF14C to activate plant immunity.
猕猴桃溃疡病菌引起的细菌性溃疡病是威胁全球猕猴桃生产的最具破坏性的疾病。该病原体将多种效应蛋白输送到植物细胞中，以抵抗植物的免疫反应并促进其存活。在这里，我们专注于 pv. () 中独特的效应物 HopZ5，先前已有报道称其具有毒力功能。在本研究中，我们的结果表明，HopZ5 可以通过农杆菌浸润在 中引起宏观细胞死亡并引发严重的免疫反应，同时上调免疫相关基因的表达和活性氧和胼胝质的大量积累。随后，我们证实 HopZ5 可以与非宿主植物 () 中的磷酸丝氨酸结合蛋白 GF14C（NbGF14C）和宿主植物猕猴桃（AcGF14C）相互作用，并且沉默 NbGF14C 会损害 HopZ5 介导的细胞死亡，表明 GF14C 在检测 HopZ5 中起关键作用。进一步的研究表明，过表达 NbGF14C 明显降低了 在 中的感染和过表达 AcGF14C 显著增强了猕猴桃对 的抗性，表明 GF14C 正向调节植物免疫。总之，我们的结果表明，毒力效应物 HopZ5 可以被植物识别，并与 GF14C 相互作用激活植物免疫。
