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Article|22 Jul 2022|OPEN
Susceptibility factor StEXA1 interacts with StnCBP to facilitate potato virus Y accumulation through the stress granule-dependent RNA regulatory pathway in potato
Ruhao Chen1,2 , Zhen Tu1 , Changzheng He2 , Xianzhou Nie3 , Kun Li1 , Sitian Fei1 , Botao Song1 and Bihua Nie1 , , Conghua Xie,1
1Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
2ERC for Germplasm Innovation and New Variety Breeding of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, Hunan Agricultural University, Changsha, 410128, China
3Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, New Brunswick, E3B 4Z7, Canada
*Corresponding author. E-mail: nbihua@mail.hzau.edu.cn

Horticulture Research 9,
Article number: uhac159 (2022)
doi: https://doi.org/10.1093/hr/uhac159
Views: 92

Received: 13 Feb 2022
Accepted: 06 Jul 2022
Published online: 22 Jul 2022

Abstract

Plant viruses recruit multiple host factors for translation, replication, and movement in the infection process. The loss-of-function mutation of the susceptibility genes will lead to the loss of susceptibility to viruses, which is referred to as ‘recessive resistance’. Essential for potexvirus Accumulation 1 (EXA1) has been identified as a susceptibility gene required for potexvirus, lolavirus, and bacterial and oomycete pathogens. In this study, EXA1 knockdown in potato (StEXA1) was found to confer novel resistance to potato virus Y (PVY, potyvirus) in a strain-specific manner. It significantly compromised PVYO accumulation but not PVYN:O and PVYNTN. Further analysis revealed that StEXA1 is associated with the HC-Pro of PVY through a member of eIF4Es (StnCBP). HC-ProO and HC-ProN, two HC-Pro proteins from PVYO and PVYN, exhibited strong and weak interactions with StnCBP, respectively, due to their different spatial conformation. Moreover, the accumulation of PVYO was mainly dependent on the stress granules (SGs) induced by StEXA1 and StnCBP, whereas PVYN:O and PVYNTN could induce SGs by HC-ProN independently through an unknown mechanism. These results could explain why StEXA1 or StnCBP knockdown conferred resistance to PVYO but not to PVYN:O and PVYNTN. In summary, our results for the first time demonstrate that EXA1 can act as a susceptibility gene for PVY infection. Finally, a hypothetical model was proposed for understanding the mechanism by which StEXA1 interacts with StnCBP to facilitate PVY accumulation in potato through the SG-dependent RNA regulatory pathway.