@article{GhirardoNosenkoKreuzwieseretal.2021, author = {Ghirardo, Andrea and Nosenko, Tetyana and Kreuzwieser, J{\"u}rgen and Winkler, J. Barbro and Kruse, J{\"o}rg and Albert, Andreas and Merl-Pham, Juliane and Lux, Thomas and Ache, Peter and Zimmer, Ina and Alfarraj, Saleh and Mayer, Klaus F. X. and Hedrich, Rainer and Rennenberg, Heinz and Schnitzler, J{\"o}rg-Peter}, title = {Protein expression plasticity contributes to heat and drought tolerance of date palm}, series = {Oecologia}, volume = {197}, journal = {Oecologia}, number = {4}, issn = {0029-8549}, doi = {10.1007/s00442-021-04907-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-308075}, pages = {903-919}, year = {2021}, abstract = {Climate change is increasing the frequency and intensity of warming and drought periods around the globe, currently representing a threat to many plant species. Understanding the resistance and resilience of plants to climate change is, therefore, urgently needed. As date palm (Phoenix dactylifera) evolved adaptation mechanisms to a xeric environment and can tolerate large diurnal and seasonal temperature fluctuations, we studied the protein expression changes in leaves, volatile organic compound emissions, and photosynthesis in response to variable growth temperatures and soil water deprivation. Plants were grown under controlled environmental conditions of simulated Saudi Arabian summer and winter climates challenged with drought stress. We show that date palm is able to counteract the harsh conditions of the Arabian Peninsula by adjusting the abundances of proteins related to the photosynthetic machinery, abiotic stress and secondary metabolism. Under summer climate and water deprivation, these adjustments included efficient protein expression response mediated by heat shock proteins and the antioxidant system to counteract reactive oxygen species formation. Proteins related to secondary metabolism were downregulated, except for the P. dactylifera isoprene synthase (PdIspS), which was strongly upregulated in response to summer climate and drought. This study reports, for the first time, the identification and functional characterization of the gene encoding for PdIspS, allowing future analysis of isoprene functions in date palm under extreme environments. Overall, the current study shows that reprogramming of the leaf protein profiles confers the date palm heat- and drought tolerance. We conclude that the protein plasticity of date palm is an important mechanism of molecular adaptation to environmental fluctuations.}, language = {en} } @article{LuDreyerDickinsonetal.2023, author = {Lu, Jinping and Dreyer, Ingo and Dickinson, Miles Sasha and Panzer, Sabine and Jaślan, Dawid and Navarro-Retamal, Carlos and Geiger, Dietmar and Terpitz, Ulrich and Becker, Dirk and Stroud, Robert M. and Marten, Irene and Hedrich, Rainer}, title = {Vicia faba SV channel VfTPC1 is a hyperexcitable variant of plant vacuole two pore channels}, series = {eLife}, volume = {12}, journal = {eLife}, doi = {10.7554/eLife.86384}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350264}, year = {2023}, abstract = {To fire action-potential-like electrical signals, the vacuole membrane requires the two-pore channel TPC1, formerly called SV channel. The TPC1/SV channel functions as a depolarization-stimulated, non-selective cation channel that is inhibited by luminal Ca\(^{2+}\). In our search for species-dependent functional TPC1 channel variants with different luminal Ca\(^{2+}\) sensitivity, we found in total three acidic residues present in Ca\(^{2+}\) sensor sites 2 and 3 of the Ca\(^{2+}\)-sensitive AtTPC1 channel from Arabidopsis thaliana that were neutral in its Vicia faba ortholog and also in those of many other Fabaceae. When expressed in the Arabidopsis AtTPC1-loss-of-function background, wild-type VfTPC1 was hypersensitive to vacuole depolarization and only weakly sensitive to blocking luminal Ca\(^{2+}\). When AtTPC1 was mutated for these VfTPC1-homologous polymorphic residues, two neutral substitutions in Ca\(^{2+}\) sensor site 3 alone were already sufficient for the Arabidopsis At-VfTPC1 channel mutant to gain VfTPC1-like voltage and luminal Ca\(^{2+}\) sensitivity that together rendered vacuoles hyperexcitable. Thus, natural TPC1 channel variants exist in plant families which may fine-tune vacuole excitability and adapt it to environmental settings of the particular ecological niche.}, language = {en} } @article{DindasScherzerRoelfsemaetal.2018, author = {Dindas, Julian and Scherzer, S{\"o}nke and Roelfsema, M. Rob G. and Meyer, Katharina von and M{\"u}ller, Heike M. and Al-Rasheid, K. A. S. and Palme, Klaus and Dietrich, Petra and Becker, Dirk and Bennett, Malcolm J. and Hedrich, Rainer}, title = {AUX1-mediated root hair auxin influx governs SCFTIR1/AFB-type Ca2+ signaling}, series = {Nature Communications}, volume = {9}, journal = {Nature Communications}, doi = {10.1038/s41467-018-03582-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225368}, year = {2018}, abstract = {Auxin is a key regulator of plant growth and development, but the causal relationship between hormone transport and root responses remains unresolved. Here we describe auxin uptake, together with early steps in signaling, in Arabidopsis root hairs. Using intracellular microelectrodes we show membrane depolarization, in response to IAA in a concentration- and pH-dependent manner. This depolarization is strongly impaired in aux1 mutants, indicating that AUX1 is the major transporter for auxin uptake in root hairs. Local intracellular auxin application triggers Ca2+ signals that propagate as long-distance waves between root cells and modulate their auxin responses. AUX1-mediated IAA transport, as well as IAA- triggered calcium signals, are blocked by treatment with the SCFTIR1/AFB - inhibitor auxinole. Further, they are strongly reduced in the tir1afb2afb3 and the cngc14 mutant. Our study reveals that the AUX1 transporter, the SCFTIR1/AFB receptor and the CNGC14 Ca2+ channel, mediate fast auxin signaling in roots.}, language = {en} }