@article{KarimiFreundWageretal.2021, author = {Karimi, Sohail M. and Freund, Matthias and Wager, Brittney M. and Knoblauch, Michael and Fromm, J{\"o}rg and M. Mueller, Heike and Ache, Peter and Krischke, Markus and Mueller, Martin J. and M{\"u}ller, Tobias and Dittrich, Marcus and Geilfus, Christoph-Martin and Alfaran, Ahmed H. and Hedrich, Rainer and Deeken, Rosalia}, title = {Under salt stress guard cells rewire ion transport and abscisic acid signaling}, series = {New Phytologist}, volume = {231}, journal = {New Phytologist}, number = {3}, doi = {10.1111/nph.17376}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259635}, pages = {1040-1055}, year = {2021}, abstract = {Soil salinity is an increasingly global problem which hampers plant growth and crop yield. Plant productivity depends on optimal water-use efficiency and photosynthetic capacity balanced by stomatal conductance. Whether and how stomatal behavior contributes to salt sensitivity or tolerance is currently unknown. This work identifies guard cell-specific signaling networks exerted by a salt-sensitive and salt-tolerant plant under ionic and osmotic stress conditions accompanied by increasing NaCl loads. We challenged soil-grown Arabidopsis thaliana and Thellungiella salsuginea plants with short- and long-term salinity stress and monitored genome-wide gene expression and signals of guard cells that determine their function. Arabidopsis plants suffered from both salt regimes and showed reduced stomatal conductance while Thellungiella displayed no obvious stress symptoms. The salt-dependent gene expression changes of guard cells supported the ability of the halophyte to maintain high potassium to sodium ratios and to attenuate the abscisic acid (ABA) signaling pathway which the glycophyte kept activated despite fading ABA concentrations. Our study shows that salinity stress and even the different tolerances are manifested on a single cell level. Halophytic guard cells are less sensitive than glycophytic guard cells, providing opportunities to manipulate stomatal behavior and improve plant productivity.}, language = {en} } @article{FerberGerhardsSaueretal.2020, author = {Ferber, Elena and Gerhards, Julian and Sauer, Miriam and Krischke, Markus and Dittrich, Marcus T. and M{\"u}ller, Tobias and Berger, Susanne and Fekete, Agnes and Mueller, Martin J.}, title = {Chemical Priming by Isothiocyanates Protects Against Intoxication by Products of the Mustard Oil Bomb}, series = {Frontiers in Plant Science}, volume = {11}, journal = {Frontiers in Plant Science}, issn = {1664-462X}, doi = {10.3389/fpls.2020.00887}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207104}, year = {2020}, abstract = {In Brassicaceae, tissue damage triggers the mustard oil bomb i.e., activates the degradation of glucosinolates by myrosinases leading to a rapid accumulation of isothiocyanates at the site of damage. Isothiocyanates are reactive electrophilic species (RES) known to covalently bind to thiols in proteins and glutathione, a process that is not only toxic to herbivores and microbes but can also cause cell death of healthy plant tissues. Previously, it has been shown that subtoxic isothiocyanate concentrations can induce transcriptional reprogramming in intact plant cells. Glutathione depletion by RES leading to breakdown of the redox potential has been proposed as a central and common RES signal transduction mechanism. Using transcriptome analyses, we show that after exposure of Arabidopsis seedlings (grown in liquid culture) to subtoxic concentrations of sulforaphane hundreds of genes were regulated without depletion of the cellular glutathione pool. Heat shock genes were among the most highly up-regulated genes and this response was found to be dependent on the canonical heat shock factors A1 (HSFA1). HSFA1-deficient plants were more sensitive to isothiocyanates than wild type plants. Moreover, pretreatment of Arabidopsis seedlings with subtoxic concentrations of isothiocyanates increased resistance against exposure to toxic levels of isothiocyanates and, hence, may reduce the autotoxicity of the mustard oil bomb by inducing cell protection mechanisms.}, language = {en} }