Responses to High Temperatures
warming has a negative impact on the yield of many crops around the globe.
Currently the generation of varieties that can ensure a high and sustainable
production of food is important to secure the nutrition of the growing human
population. Our group aims to understand the fundamental cellular and
organismic process that are activated when plants are exposed to high
temperatures and reveal how they contribute to thermotolerance.
specifically address the following questions:
•How do plants respond to increased
temperatures and what are the key processes that lead to thermotolerance?
•Why some plant genotypes, organs, tissues
or even cell types within the plant body are more sensitive to heat stress
compared to others?
•How can we improve the resilience of
crops to high temperature and secure food production under more unfavourable
to induce defence mechanisms collectively called heat stress response to ensure
survival and recovery from stress. At the molecular level, thermotolerance is
mainly dependent on the maintenance of protein homeostasis which under stress
conditions is accomplished by the accumulation of molecular chaperones such as
many heat shock proteins (HSP). In addition to HSPs, hundreds other genes with
various functions are induced under high temperatures, leading to an extensive
cellular metabolic reprogramming.
in transcriptome profile are mainly mediated by members of the heat stress
transcription factor (Hsfs) gene family. Plants comprise a large number of
Hsf-coding genes (e.g. 27 in tomato). We have demonstrated the function of
three major Hsfs in tomato plant, namely HsfA1a, HsfA2 and HsfB1 in the onset
of heat stress response and recovery from stress, but also in acclimation
processes to high temperatures. We are currently characterizing additional
members with tissue- and/or temperature-specific functions.
addition, many Hsfs as well as other HS-regulated genes undergo alternative
splicing under high temperatures. Alternative splicing controls transcriptome
abundance and proteome diversity and therefore has a prominent role in
thermotolerance. Consequently, we aim to uncover temperature-sensitive
alternative splicing events that are related to thermotolerance and identify
key factors involved in this process.
reach our goals we engage various approaches using genetic, physiology,
molecular and cell biology tools, as well as genomic approaches.
representative publications of our group:Identification and Regulation of Tomato Serine/Arginine-Rich Proteins Under High Temperatures.
Rosenkranz RRE, Bachiri S, Vraggalas S, Keller M, Simm S, Schleiff E, Fragkostefanakis S. Front Plant Sci. 2021 Mar 29;12:645689. doi: 10.3389/fpls.2021.645689. PMID: 33854522; PMCID: PMC8039515.Natural variation in HsfA2 pre-mRNA splicing is associated with changes in thermotolerance during tomato domestication
Hu Y, Mesihovic A, Jiménez-Gómez JM, Röth S, Gebhardt P, Bublak D, Bovy A, Scharf KD, Schleiff E, Fragkostefanakis S. New Phytol. 2020 Feb;225(3):1297-1310. doi: 10.1111/nph.16221. Epub 2019 Nov 14. PMID: 31556121The repressor and co-activator HsfB1 regulates the major heat stress transcription factors in tomato.
Fragkostefanakis S, Simm S, El-Shershaby A, Hu Y, Bublak D, Mesihovic A, Darm K, Mishra SK, Tschiersch B, Theres K, Scharf C, Schleiff E, Scharf KD. Plant Cell Environ. 2019 Mar;42(3):874-890. doi: 10.1111/pce.13434. Epub 2018 Oct 11. PMID: 30187931Alternative splicing in tomato pollen in response to heat stress.
Keller M, Hu Y, Mesihovic A, Fragkostefanakis S, Schleiff E, Simm S. DNA Res. 2017 Apr 1;24(2):205-217. doi: 10.1093/dnares/dsw051. PMID: 28025318HsfA2 Controls the Activity of Developmentally and Stress-Regulated Heat Stress Protection Mechanisms in Tomato Male Reproductive Tissues.
Fragkostefanakis S, Mesihovic A, Simm S, Paupière MJ, Hu Y, Paul P, Mishra SK, Tschiersch B, Theres K, Bovy A, Schleiff E, Scharf KD. Plant Physiol. 2016 Apr;170(4):2461-77. doi: 10.1104/pp.15.01913. Epub 2016 Feb 25. PMID: 26917685