desiccation tolerance; drought stress; senescence; oxidative stress; chlorophyll breakdown
Durgud Meriem, Gupta Saurabh, Ivanov Ivan, Omidbakhshfard M. Amin, Benina Maria, Alseekh Saleh, Staykov Nikola, Hauenstein Mareike, Dijkwel Paul P., Hörtensteiner Stefan, Toneva Valentina, Brotman Yariv, Fernie Alisdair R., Mueller-Roeber Bernd, Gechev Tsanko S. (2018), Molecular Mechanisms Preventing Senescence in Response to Prolonged Darkness in a Desiccation-Tolerant Plant, in Plant Physiology
, 177(3), 1319-1338.
Petrov V, Hille J, Mueller-Roeber B, Gechev T (2015), ROS-mediated abiotic stress-induced programmed cell death in plants, in Frontiers in Plant Science
, 6, 69.
Gechev Tsanko S, Hille Jacques, Woerdenbag Herman J, Benina Maria, Mehterov Nikolay, Toneva Valentina, Fernie Alisdair R, Mueller-Roeber Bernd (2014), Natural products from resurrection plants: potential for medical applications., in Biotechnology advances
, 32(6), 1091-101.
Christ Bastien, Egert Aurélie, Süssenbacher Iris, Kräutler Bernhard, Bartels Dorothea, Peters Shaun, Hörtensteiner Stefan (2014), Water deficit induces chlorophyll degradation via the 'PAO/phyllobilin' pathway in leaves of homoio- (Craterostigma pumilum) and poikilochlorophyllous (Xerophyta viscosa) resurrection plants., in Plant, cell & environment
, 37(11), 2521-31.
Gechev T, Mehterov N, Denev I, Hille J (2013), A simple and powerful approach for isolation of Arabidopsis mutants with increased tolerance to H2
-induced cell death., in Methods in Enzymology
, 527, 203-220.
Benina M, Obata TS, Mehterov N, Ivanov I, Petrov V, Toneva V, Fernie AR, Gechev T, Comparative metabolomics of Haberlea rhodopensis
, Thellungiella halophyla
, and Arabidopsis thaliana
exposed to low temperature and subsequent recovery, in Frontiers in Plant Science
Abiotic stresses such as drought and extreme temperatures are the most prominent threat to agriculture worldwide, leading to crop losses or/and plant cell death. Furthermore, adverse environmental conditions can often cause accelerated senescence and shorten plant life span. Both stress tolerance and ageing are genetically controlled processes and there are indications that in plants, like in animals, reactive oxygen species are involved in this genetic control. The aim of this project is to identify elements of the genetic network that regulate the two intricately connected processes. Three alternative approaches will be used to discover genes involved in the regulation of abiotic stress tolerance and plant ageing: 1) Exploring the molecular mechanisms of stress tolerance in Haberlea rhodopensis. This is a unique resurrection plant and glacial relic with remarkable ability to survive desiccation (less than 5% relative water content) when dried for more than two weeks and resume its normal growth within hours after re-watering. In addition to drought, H. rhodopensis can also tolerate very low temperatures (chilling and freezing stress). 2) Comparative transcriptome and metabolome analysis between the stress resistant H. rhodopensis, stress tolerant Thelungiella halophila, and stress sensitive Arabidopsis thaliana. 3) Analysis of mutants with increased tolerance to abiotic stress factors and modulated senescence. To perform these approaches, the desiccation- and freezing-tolerant H. rhodopensis will be exposed to mild drought stress, followed by severe desiccation and subsequent rehydration, as well as to chilling and freezing temperatures followed by return to optimal growth temperatures. Transcriptome and metabolome analysis under these conditions will be performed using next generation sequencing (NGS) combined with advanced bioinformatics and gas/liquid chromatography coupled with mass spectrometry, respectively. In parallel, the same experiments will be performed with T. halophila and the closely related A. thaliana. With this approach, novel genes highly regulated under these conditions will be identified and their possible significance be evaluated by the comparative analysis between the three species with different levels of stress tolerance. In parallel, the changes in the metabolite abundances of the three species under drought and low temperature stress will complement the gene expression studies and outline metabolites that may contribute to stress tolerance.As an alternative approach, a number of A. thaliana mutants with enhanced abiotic/oxidative stress tolerance and delayed senescence, generated in our groups, will be investigated in more detail in order to get insights on the molecular mechanisms that determine abiotic/oxidative stress tolerance and regulate plant ageing. The analysis will include but not be limited to positional cloning of the genes responsible for the stress tolerant phenotypes/delayed ageing, comparative transcriptome and metabolome analysis of the mutants and wild type plants exposed to stress conditions. Additionally, H. rhodopensis genes and their homologues in A. thaliana identified previously as potential major players in abiotic stress tolerance will be functionally evaluated in A. thaliana by generating transgenic overexpressing and knockout/RNAi plants with altered levels of the respected gene products.This study is expected to uncover intricate molecular mechanisms that determine drought/low temperature stress tolerance and plant lifespan. Identifying new genes involved in the regulation of plant abiotic stress tolerance and unraveling the genetic mechanisms of plant ageing is not only of fundamental importance but also of practical significance for generating crops with improved qualities and increased productivity. Thus, a broader impact is expected on the agricultural sector of the economy.The project will engage three young researchers/PhD students (two in Bulgaria, one in Switzerland). Collaboration with other research groups and institutes is envisaged (in particular, with the Max Planck Institute of Molecular Plant Physiology, Golm, Germany, and Bayer Biosciences, Gent, Belgium).