TY - JOUR A1 - Ghirardo, Andrea A1 - Nosenko, Tetyana A1 - Kreuzwieser, Jürgen A1 - Winkler, J. Barbro A1 - Kruse, Jörg A1 - Albert, Andreas A1 - Merl-Pham, Juliane A1 - Lux, Thomas A1 - Ache, Peter A1 - Zimmer, Ina A1 - Alfarraj, Saleh A1 - Mayer, Klaus F. X. A1 - Hedrich, Rainer A1 - Rennenberg, Heinz A1 - Schnitzler, Jörg-Peter T1 - Protein expression plasticity contributes to heat and drought tolerance of date palm JF - Oecologia N2 - 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. KW - abiotic stress KW - isoprene KW - proteomics KW - photosynthesis KW - Phoenix dactylifera Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-308075 SN - 0029-8549 SN - 1432-1939 VL - 197 IS - 4 ER - TY - JOUR A1 - Büdel, Burkhard A1 - Vivas, Mercedes A1 - Lange, Otto L. T1 - Lichen species dominance and the resulting photosynthetic behavior of sonoran desert soil crust types (Baja California, Mexico) JF - Ecological Processes N2 - Introduction: Lichen dominated biological soil crusts (BSCs) occur over large areas in the Sonoran Desert of the southwestern USA and northwest Mexico. In Baja California BSCs show a distinct patchiness and several types can be distinguished. Two chlorolichen- and two cyanolichen-dominated BSCs were selected. We hypothesize that patchiness and the resulting domination of certain functional lichen groups will result in patchiness of photosynthetic CO2-uptake related to environmental factors as well. Methods: Four different soil crust samples were placed in cuvettes and their CO2 exchange was recorded in an open system with an infrared gas analyzer. Air blown over the BSCs had a controlled CO2 content of 350 ppm. Four cuvettes were operated in parallel. Photosynthetic CO2 exchange was continually recorded throughout the experiment. Results: Besides the dominating chlorolichens Psora decipiens and Placidium squamulosum and the cyanolichens Peltula patellata and P. richardsii, several other lichen species and 12 cyanobacterial species were found in the biological soil crusts sampled. The chlorolichen BSCs already gained positive net photosynthesis with high air humidity alone, while the cyanolichen types did not, but showed smaller CO2-uptake depression after water suprasaturation. Such specific net photosynthesis responses to mode of hydration and to crust water content seem to correlate with precipitation characteristics of their habitat. Conclusions: Species specific photosynthetic performance related to activation of respiration and net photosynthesis as well as to crust water content help to explain niche occupation and species composition of BSCs. Different functional types have to be considered when they have a patchy distribution. KW - patchiness KW - cyanobacterium KW - desert soil KW - dominance KW - lichen KW - photosynthesis KW - reactivation KW - soil crust KW - Baja California [(PNN) Mexico] KW - Mexico [North America] KW - Sonoran Desert KW - cyanobacteria KW - peltula patellata KW - placidium KW - psora decipiens Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131878 VL - 2 IS - 6 ER -