A reversible light- and genotype-dependent acquired thermotolerance response protects the potato plant from damage due to excessive temperature

Abstract

Main conclusionA powerful acquired thermotolerance response in potato was demonstrated and characterised in detail, showing the time course required for tolerance, the reversibility of the process and requirement for light.Potato is particularly vulnerable to increased temperature, considered to be the most important uncontrollable factor affecting growth and yield of this globally significant crop. Here, we describe an acquired thermotolerance response in potato, whereby treatment at a mildly elevated temperature primes the plant for more severe heat stress. We define the time course for acquiring thermotolerance and demonstrate that light is essential for the process. In all four commercial tetraploid cultivars that were tested, acquisition of thermotolerance by priming was required for tolerance at elevated temperature. Accessions from several wild-type species and diploid genotypes did not require priming for heat tolerance under the test conditions employed, suggesting that useful variation for this trait exists. Physiological, transcriptomic and metabolomic approaches were employed to elucidate potential mechanisms that underpin the acquisition of heat tolerance. This analysis indicated a role for cell wall modification, auxin and ethylene signalling, and chromatin remodelling in acclimatory priming resulting in reduced metabolic perturbation and delayed stress responses in acclimated plants following transfer to 40 °C.Electronic supplementary materialThe online version of this article (10.1007/s00425-018-2874-1) contains supplementary material, which is available to authorized users.

The thermal tolerance of photosynthetic tissues: a global systematic review and agenda for future research

“…Adopting more realistic regimes and justifying these with data from relevant natural settings, as well as providing better descriptions of the temperature ranges around set points would enable a more nuanced investigation of the differences between acute and chronic stress responses, and between facultative protective responses and signs of irreparable damage (Lai & He, 2016; Trapero‐Mozos et al ., 2018). At present, the definition and use of ‘stress’ and ‘stressful events’ is somewhat ad hoc and impedes our ability to compare results or derive generalizations (Jansen & Potters, 2017).…”

Physiological, Biochemical, and Transcriptional Responses to Single and Combined Abiotic Stress in Stress-Tolerant and Stress-Sensitive Potato Genotypes

“…Recent work has demonstrated the mechanisms by which tuberization signaling and initiation is impaired at elevated temperature (Lehretz et al, 2019;Morris et al, 2019). However, there is wide variation for heat stress tolerance across potato germplasm that could be exploited to ensure the sustainability of yield in warmer climates (Levy and Veilleux, 2007;Trapero-Mozos et al, 2018a).…”

Physiological and growth responses of potato cultivars to heat stress

“…Also, an adverse effect on photosynthesis resulting from chlorophyll loss and reduced CO 2 fixation has been reported for tuber-forming Solanum species (Reynolds et al 1990). A large number of differentially expressed genes involved in many biological processes and molecular functions as well as differential metabolite accumulation have been identified in response to mild to moderate heat stress in potato leaves and tubers (Hancock et al 2014;Trapero-Mozos et al 2018). Tolerance to elevated temperatures in potato is likely a polygenic trait and, thus expected to be substantially influenced by genotype-environment interactions.…”