Transcriptomic regulation of potato in response to drought stress

Abstract

Limited crop production due to lower rainfall has a major impact on the supply and demand of food for the human population. In potato (Solanum tuberosum L.), one of the major crops, there is also concern about a lack of production due to drought stress. Especially the cultivar "Toyoshiro" suitable for processing, has significant reduction in drought yield. Therefore, it is necessary to understand the mechanism of gene expression changes that occur in potato "Toyoshiro" plants and tubers during drought. Seed potatoes were split in half and one was used as a control plant that was watered daily, and the other was used as a drought-stressed plant that was watered off to mimic the weather conditions of the Tokachi-Obihiro region in 2021. These tubers were harvested at week 14 and the transcriptome was analyzed. The stressed plants showed 423 downregulated genes and 197 upregulated genes compared to the control. Factors related to phytosterol metabolism, cell wall modification, and heat stress response were detected among the genes whose expression changed. Moreover, the expression of "Abscisic acid and environmental stress-inducible protein TAS14 like (TAS14)," a molecule reported to be upregulated in several cultivars under drought stress, was also upregulated, and the localization of this molecule in the nucleus and plasma membrane was confirmed in an mCherry-tagged TAS14 mutant line. These results contribute to understanding the survival strategy system of potatoes in response to drought stress.