**5. Conclusions**

Heat stress imparted deleterious effects on photosynthesis and plant water status that led to reduce the plant growth and yield in camelina varieties. Nevertheless, osmoriming with thiourea (500 ppm) improved the growth and yield of both varieties of camelina under normal and heat-stressed conditions. Thiourea priming upregulated the plant water relations to regulate stomatal conductance and photosynthetic efficiency, which added to improve crop yield. It was also inferred that camelina variety 8046 performed better against heat stress as compared to 7126 grown under high-temperature stress. Overall, this study provides a good understanding for scientists to find out the actual physiological mechanisms behind the thiourea induced heat stress tolerance mechanism in camelina that will be a roadmap for the further investigation at cellular level.

**Author Contributions:** Conceptualization, E.A.W., M.A. and M.T.M.; methodology, M.T.M., M.A.; software, A.E.S.; validation, E.A.W., Z.A., M.H.-U.-R., W.S. and A.E.S.; formal analysis, Z.A.; investigation, M.A., M.T.M., Z.A.; resources, EA.W and A.E.S.; data curation, W.S., A.E.S., M.A.; writing—original draft preparation, E.A.W., M.A., M.T.M. and A.E.S.; writing—review and editing, M.A., M.H.-U.-R., W.S. and A.E.S. and supervision, E.A.W.; funding acquisition, W.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** This Research was funded by the Researchers Supporting Project number (RSP-2021/390), King Saud University, Riyadh, Saudi Arabia.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data is contained within the article.

**Acknowledgments:** This research was funded by the Researchers Supporting Project number (RSP-2021/390), King Saud University, Riyadh, Saudi Arabia.

**Conflicts of Interest:** The authors declare no conflict of interest.
