TY  - JOUR
A1  - Gechev, Tsanko S.
A1  - Benina, Maria
A1  - Obata, Toshihiro
A1  - Tohge, Takayuki
A1  - Neerakkal, Sujeeth
A1  - Minkov, Ivan
A1  - Hille, Jacques
A1  - Temanni, Mohamed-Ramzi
A1  - Marriott, Andrew S.
A1  - Bergström, Ed
A1  - Thomas-Oates, Jane
A1  - Antonio, Carla
A1  - Müller-Röber, Bernd
A1  - Schippers, Jos H. M.
A1  - Fernie, Alisdair R.
A1  - Toneva, Valentina
T1  - Molecular mechanisms of desiccation tolerance in the resurrection glacial relic Haberlea rhodopensis
JF  - Cellular and molecular life sciences
N2  - Haberlea rhodopensis is a resurrection plant with remarkable tolerance to desiccation. Haberlea exposed to drought stress, desiccation, and subsequent rehydration showed no signs of damage or severe oxidative stress compared to untreated control plants. Transcriptome analysis by next-generation sequencing revealed a drought-induced reprogramming, which redirected resources from growth towards cell protection. Repression of photosynthetic and growth-related genes during water deficiency was concomitant with induction of transcription factors (members of the NAC, NF-YA, MADS box, HSF, GRAS, and WRKY families) presumably acting as master switches of the genetic reprogramming, as well as with an upregulation of genes related to sugar metabolism, signaling, and genes encoding early light-inducible (ELIP), late embryogenesis abundant (LEA), and heat shock (HSP) proteins. At the same time, genes encoding other LEA, HSP, and stress protective proteins were constitutively expressed at high levels even in unstressed controls. Genes normally involved in tolerance to salinity, chilling, and pathogens were also highly induced, suggesting a possible cross-tolerance against a number of abiotic and biotic stress factors. A notable percentage of the genes highly regulated in dehydration and subsequent rehydration were novel, with no sequence homology to genes from other plant genomes. Additionally, an extensive antioxidant gene network was identified with several gene families possessing a greater number of antioxidant genes than most other species with sequenced genomes. Two of the transcripts most abundant during all conditions encoded catalases and five more catalases were induced in water-deficient samples. Using the pharmacological inhibitor 3-aminotriazole (AT) to compromise catalase activity resulted in increased sensitivity to desiccation. Metabolome analysis by GC or LC-MS revealed accumulation of sucrose, verbascose, spermidine, and gamma-aminobutyric acid during drought, as well as particular secondary metabolites accumulating during rehydration. This observation, together with the complex antioxidant system and the constitutive expression of stress protective genes suggests that both constitutive and inducible mechanisms contribute to the extreme desiccation tolerance of H. rhodopensis.
KW  - Antioxidant genes
KW  - Catalase
KW  - Desiccation tolerance
KW  - Drought stress
KW  - Metabolome analysis
KW  - Resurrection plants
Y1  - 2013
U6  - https://doi.org/10.1007/s00018-012-1155-6
SN  - 1420-682X
VL  - 70
IS  - 4
SP  - 689
EP  - 709
PB  - Springer
CY  - Basel
ER  - 
TY  - JOUR
A1  - Petrov, Veselin
A1  - Schippers, Jos
A1  - Benina, Maria
A1  - Minkov, Ivan
A1  - Müller-Röber, Bernd
A1  - Gechev, Tsanko S.
T1  - In search for new players of the oxidative stress network by phenotyping an Arabidopsis T-DNA mutant collection on reactive oxygen species-eliciting chemicals
JF  - Plant omics
N2  - The ability of some chemical compounds to cause oxidative stress offers a fast and convenient way to study the responses of plants to reactive oxygen species (ROS). In order to unveil potential novel genetic players of the ROS-regulatory network, a population of similar to 2,000 randomly selected Arabidopsis thaliana T-DNA insertion mutants was screened for ROS sensitivity/resistance by growing seedlings on agar medium supplemented with stress-inducing concentrations of the superoxide-eliciting herbicide methyl viologen or the catalase inhibitor 3-amino-triazole. A semi-robotic setup was used to capture and analyze images of the chemically treated seedlings which helped interpret the screening results by providing quantitative information on seedling area and healthy-to-chlorotic tissue ratios for data verification. A ROS-related phenotype was confirmed in three of the initially selected 33 mutant candidates, which carry T-DNA insertions in genes encoding a Ring/Ubox superfamily protein, ABI5 binding protein 1 (AFP1), previously reported to be involved in ABA signaling, and a protein of unknown function, respectively. In addition, we identified six mutants, most of which have not been described yet, that are related to growth or chloroplast development and show defects in a ROS-independent manner. Thus, semi-automated image capturing and phenotyping applied on publically available T-DNA insertion collections adds a simple means for discovering novel mutants in complex physiological processes and identifying the genes involved.
KW  - growth
KW  - image analysis
KW  - methyl viologen
KW  - LemnaTec
KW  - screening
KW  - superoxide
Y1  - 2013
SN  - 1836-0661
VL  - 6
IS  - 1
SP  - 46
EP  - 54
PB  - Southern Cross Publ.
CY  - Lismore
ER  -