The Effects of Chronic Elevated Temperatures on Potato (Solanum tuberosum L.) Tuber Development

Abstract

With global temperatures rising due to climate change, many crops are being adversely affected. Potato (Solanum tuberosum L.) is the fourth most important food crop in the world and is especially vulnerable to heat stress, facing significant yield loss when exposed to temperatures higher than 28°C. Many studies have attempted to understand this effect of heat stress on potato, but the exact mechanisms behind this inhibition remain unknown. It is understood that the environmental conditions potatoes experience during the growing period have significant impacts on the tuberization process, as signals initiated in leaves integrate environmental and circadian factors to determine the timing of tuberization. However, very few studies have examined the effects of heat stress on tubers throughout varying stages of development. A FLOWERING-LOCUS T (FT) homolog in potato, referred to as StSP6A, controls tuberization and is known to be downregulated under heat stress, contributing to the decrease in sucrose synthesis, transport, and ultimate crop yield loss. Previous studies have found an important role of SP6A in tuber initiation, but results suggest that other genes are responsible for the continued growth of tubers. Significant knowledge gaps remain in our understanding of the genes responsible for tuberization signaling, especially under the context of elevated temperature. This study uses whole-plant physiology, transcriptomics, and hormone profiling to gain insight into the molecular mechanisms behind heat stress impacts on potato tuber development.