Skip to main content
ARS Home » Pacific West Area » Pullman, Washington » WHGQ » Research » Publications at this Location » Publication #422325
Research Project: Enhancing Control of Stripe Rusts of Cereal Crops

Location: Wheat Health, Genetics, and Quality Research

Title: Wheat small GTPase gene TaRABH1bL is involved in high-temperature all-stage resistance to Puccinia striiformis f. sp. tritici

Author
item SHI, YIFENG - Northwest A&f University
item BAO, XIYUE - Northwest A&f University
item LI, HAI - Northwest A&f University
item LI, YUXIANG - Northwest A&f University
item Chen, Xianming
item HU, XIAOPING - Northwest A&f University

Submitted to: Molecular Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2025
Publication Date: 8/7/2025
Citation: Shi, Y., Bao, X., Li, H., Li, Y., Chen, X., Hu, X. 2025. Wheat small GTPase gene TaRABH1bL is involved in high-temperature all-stage resistance to Puccinia striiformis f. sp. tritici. Molecular Plant Pathology. 26(8). Article e70132. https://doi.org/10.1111/mpp.70132.
DOI: https://doi.org/10.1111/mpp.70132

Interpretive Summary: As the largest subfamily of small G proteins, the Rab subfamily plays a pivotal role in regulating biotic and abiotic stresses in plants. However, the functions of Rabs in resistance to wheat stripe rust remains unclear. Here, we identified a Rab subfamily gene, TaRABH1bL, from wheat cultivar Xiaoyan 6 with non-race-specific and durable high-temperature all-stage (HTAS) resistance to stripe rust. The expression of the gene was up-regulated with stripe rust inoculation under relatively high-temperature treatments. The gene was primarily expressed in leaves. The involvement of the gene in stripe rust resistance was demenstrated by silencing the gene with barley stripe mosaic virus (BSMV) significantly reducing HTAS resistance and increasing the pathogen sporulation. The gene-coded proteins were localized in wheat cell cytoplasm and nuclei through transient expression of the gene in tobacco leaves and wheat protoplasts. TaRABH1bL interacted with the transcription factor ethylene-responsive transcription factor 1-like (TaERF1L) in the nuclei. The mutation and GDP-binding experiments showed that the transcription factor TaERF1L exclusively interacted with the GTP-binding state of the TaRABH1bL protein. Silencing TaERF1L also significantly reduced the HTAS resistance to stripe rust resistance. These results suggested that under the dual signals of stripe rust pathogen infection and relatively high-temperature treatment, TaRABH1bL interacted with the transcription factor TaERF1L in its GTP-binding state, transmitting immune signals to nuclei and regulating the HTAS resistance in XY6. The findings are useful for understanding the molecular mechanisms of wheat resistance to stripe rust.

Technical Abstract: As the largest subfamily of small G proteins, the Rab subfamily plays a pivotal role in regulating biotic and abiotic stresses in plants. However, the functions of Rabs in resistance to wheat stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) remains unclear. Here, we identified a Rab subfamily gene, TaRABH1bL, from Xiaoyan 6 (XY6), a wheat cultivar known for non-race-specific and durable high-temperature all-stage (HTAS) resistance to stripe rust. The expression of TaRABH1bL was up-regulated with Pst inoculation under relatively high-temperature treatments. The TaRABH1bL gene was primarily expressed in leaves, exhibiting higher expression levels compared to stems and roots. Barley stripe mosaic virus (BSMV)-induced TaRABH1bL gene silencing significantly reduced HTAS resistance to Pst, resulting in increased sporulation. Transient expression of TaRABH1bL in tobacco leaves and wheat protoplasts confirmed its subcellular localization in both the cytoplasm and nuclei. TaRABH1bL interacted with the transcription factor ethylene-responsive transcription factor 1-like (TaERF1L) in the nuclei. Two site-specific mutations of TaRABH1bL, GTP-binding state TaRABH1bLQ69L and GDP-binding state TaRABH1bLN122I were generated, and further assays revealed that TaERF1L exclusively interacted with the GTP-binding state TaRABH1bLQ69L. Silencing TaERF1L significantly reduced the HTAS resistance to Pst in XY6. These results suggested that under the dual signals of Pst infection and relatively high-temperature treatment, TaRABH1bL interacted with the transcription factor TaERF1L in its GTP-binding state, transmitting immune signals to nuclei and regulating the HTAS resistance in XY6.