**5. Conclusions**

Potato is among one of the most important food crops, ye<sup>t</sup> maintaining plant productivity in this drought-sensitive crop has become a challenge. From a nutrition perspective, decreasing soil water availability during tuber filling, as a function of a warming climate or as a production practice to induce senescence for an earlier harvest, may lead to a reduction in tuber quality. While mild drought increases the proportion of essential amino acids, potential losses in protein and phenolic content would outweigh the benefit. While MYB transcription factors may be targeted to reduce effects on the phenylpropanoid pathway, identification of small RNA as the regulator of patatin gene expression suggests it may be difficult to maintain patatin expression in drought-susceptible cultivars using current breeding techniques.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2073-4425/11/8/864/s1; Figure S1: Experimental conditions; Table S1: DE genes; Table S2: Raw read counts; Table S3: DE small RNA; Table S4: small RNA, targets expression.

**Author Contributions:** R.S. designed the research; J.W., R.S., R.E., B.B. performed field study; S.K., L.D.R., R.S., M.K. analyzed transcriptome data; S.K. performed bioinformatics; S.P., R.S. performed the amino acid analysis; L.D.R., R.S., S.K. wrote the manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** R.S., J.W., and B.B. received funding support from Agriculture and Agri-Food Canada.

**Acknowledgments:** The authors would like to thank Ken Achtymichuk and Greg Larson (AAFC Canada-Saskatchewan Irrigation Diversification Centre in Outlook, SK) for plot maintenance and Branimir Gjetvaj for assistance with physiological measurements.

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