The cell surface receptor chitin elicitor receptor kinase 1 (CERK1) is a well-known component of plant immunity. In a previous study, we found that OsCERK1 is also involved in regulating copper (Cu) uptake in rice, though the underlying mechanisms remain unclear. In this study, we identified proteins that interact with OsCERK1 and discovered a novel heavy metal-associated (HMA) domain-containing protein, OsHPP08. Our findings show that OsCERK1 phosphorylates and stabilizes OsHPP08. Structural analysis using AlphaFold, a yeast sensitivity assay of the Cu uptake-deficient yeast mutant, and Cu level measurements in the oshpp08 mutants and overexpression plants ( OsHPP08OE ) revealed that OsHPP08 facilitates Cu uptake. Moreover, rice seedling infection assays demonstrated that OsHPP08 positively contributes to blast resistance, and both OsCERK1 and OsHPP08 are necessary for Cu-modulated blast resistance. Further analyses suggest that OsCERK1 and OsHPP08 likely enhance blast resistance by regulating the antioxidant system and increasing the accumulation of H 2 O 2 . In conclusion, OsCERK1 promotes Cu uptake by stabilizing OsHPP08, and together they contribute to Cu-modulated blast resistance likely by modulating ROS accumulation. These results deepen our understanding of the interplay between biotic and abiotic signals in rice.
Sun Qi-Xuan,Wei Xing,Zhang Shang-Qing,Chen Ming-Li,Yang Ting,Yu Yong-Liang,Wang Jian-Hua
Copper transporter 1 (CTR1) is a transport protein involved in copper and cisplatin uptake. The visualization of cellular CTR1 migration and its redistribution is highly important in copper/cisplatin exposure/transport. However, to the best of our knowledge, this is a highly challenging task. Herein, a dual-mode imaging strategy for CTR1 is developed by hyphenating confocal laser scanning microscopy (CLSM) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) with a fluorescent/elemental bifunctional tag conjugated with anti-CTR1 antibody. The tag consists of rhodamine B and zirconium metal-organic frameworks (Zr-MOF) for CLSM fluorescence imaging and LA-ICPMS element imaging for a same group of HepG2 cells in a designated visual zone. This dual-mode imaging strategy facilitates visualization of CTR1 migration and meanwhile provides information of CTR1 redistribution in HepG2 cells by uptake of divalent copper or cisplatin. The present dual-mode imaging strategy provides in-depth information for the elucidation of CTR1 involved biological processes.
Graphical abstract
危险品化学品经营许可证（带存储）