The StUBC18-StPUB40 pair negatively regulate drought stress tolerance and influences tuber yield in potato

Abstract

The ubiquitin-proteasome system (UPS) is important for protein post-translational modification in plants. E2 (ubiquitin-conjugating enzyme) and E3 (ubiquitin ligases enzyme), key enzymes of UPS, play crucial roles in all aspects of plant development, growth, and environmental stresses. Despite extensive knowledge of UPS roles in crop growth and development, E2-E3 pair functions in potato tuber development and stress responses remain understudied. Here, we describe the role of StUBC18 (a potato E2) in drought stress tolerance. It is determined that StUBC18 (E2)-StPUB40 (E3) pair plays important roles in drought stress tolerance and potato tuber yield. StUBC18 and StPUB40 expression was downregulated under various stresses (drought, salt, polyethylene glycol, and H₂O₂). Overexpression of StUBC18 and StPUB40 in potatoes decreased drought stress tolerance, while interfering with the expression of StUBC18 and StPUB40 increased drought stress tolerance, respectively. The protein interaction test demonstrated that StUBC18 interacts with StPUB40 in the plant cell. Co-overexpression of StUBC18-StPUB40 in potato enhanced reactive oxygen species (ROS) accumulation and induced pleiotropic changes, reducing drought tolerance. Our findings revealed how the StUBC18-StPUB40 pair regulates potato drought stress tolerance by altering leaf anatomy (palisade and spongy tissue thickness) and influences tuber yield.

Acknowledgements

This research was supported by Joint Research Fund Major Project of Gansu Province (No. 24JRRA836), the Gansu Science and Technology Major Project (No.23ZDNA006), and the Key Program of Natural Science Foundation of Gansu Province (No. 22JR5RA832).

Author contributions

W.L, H.S, X.T, N.Z, and J.W. conceived and designed the experiments. W.L, X.F, and H.Z. performed the experiments. W.L, R.M, H.Z, and S.L. analyzed and interpreted the data. W.L. wrote the paper. H.S. and N.Z. revised the manuscript. All the authors discussed the results, commented on the manuscript, and approved for submission.

Data availability

All relevant data can be found within the paper and its supporting materials.

Conflict of interest statement

The authors have no conflicts of interest to declare.

Supplementary data

Supplementary data is available at Horticulture Research online.

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