Evidence for an early evolutionary emergence of γ-type carbonic anhydrases as components of mitochondrial respiratory complex I

Background  

The complexity of mitochondrial complex I (CI; NADH:ubiquinone oxidoreductase) has increased considerably relative to the homologous complex in bacteria. Comparative analyses of CI composition in animals, fungi and land plants/green algae suggest that novel components of mitochondrial CI include a set of 18 proteins common to all eukaryotes and a variable number of lineage-specific subunits. In plants and green algae, several purportedly plant-specific proteins homologous to γ-type carbonic anhydrases (γCA) have been identified as components of CI. However, relatively little is known about CI composition in the unicellular protists, the characterizations of which are essential to our understanding of CI evolution.     

Effects of Stratification, Gibberellic acid and Germination Temperature on the Germination of Betula nana

Experiments were carried out with three seed lots of Betula nana collected in 1967 from different localities in Norway. Seeds were stratified for 0-20 days in dark at +2-+3 °C on filter papers moistened with distilled water, or treated with solution of GA₃ for 24 h at room temperature, and then moved into special germination boxes that were placed in different temperature conditions. All the seed lots had conditional dormancy. Quantitatively, the dormancy was different in the different seed lots (pronenances), but there were no qualitative difference in the reaction to stratification gibberellic acid and to germination temperature. Differences between seed lots may have been due to different stage of seed development. The dormancy was deepest at low temperatures(12 and 15°C) decreasing gradually with increasing temperature (to 24 °C). The dormancy was effectively broken by a short stratification (from 5 to 15 days), and by treatment with gibberellic acid. The deeper the dormancy and the lower the germination temperature the longer the stratification that was needed for maximum germination. Similarly, the concentration of GA₃ needed for maximum germination increased with decreasing temperature and with increasing dormancy.     

The Database of European Forest Insect and Disease Disturbances: DEFID2

Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and the conservation of biodiversity, could be increasingly compromised. Despite the relevance of these detrimental effects, there are currently no spatially detailed databases that record insect and disease disturbances on forests at the pan-European scale. Here, we present the new Database of European Forest Insect and Disease Disturbances (DEFID2). It comprises over 650,000 harmonized georeferenced records, mapped as polygons or points, of insects and disease disturbances that occurred between 1963 and 2021 in European forests. The records currently span eight different countries and were acquired through diverse methods (e.g., ground surveys, remote sensing techniques). The records in DEFID2 are described by a set of qualitative attributes, including severity and patterns of damage symptoms, agents, host tree species, climate-driven trigger factors, silvicultural practices, and eventual sanitary interventions. They are further complemented with a satellite-based quantitative characterization of the affected forest areas based on Landsat Normalized Burn Ratio time series, and damage metrics derived from them using the LandTrendr spectral–temporal segmentation algorithm (including onset, duration, magnitude, and rate of the disturbance), and possible interactions with windthrow and wildfire events. The DEFID2 database is a novel resource for many large-scale applications dealing with biotic disturbances. It offers a unique contribution to design networks of experiments, improve our understanding of ecological processes underlying biotic forest disturbances, monitor their dynamics, and enhance their representation in land-climate models. Further data sharing is encouraged to extend and improve the DEFID2 database continuously. The database is freely available at https://jeodpp.jrc.ec.europa.eu/ftp/jrc-opendata/FOREST/DISTURBANCES/DEFID2/ .     

Temperature alternations and the influence of gibberellins and indoleacetic acid on elongation growth and flowering of Begonia x hiemalis Fotsch

The aim of this study was to investigate the role of plant hormones, particularly the gibberellins (GAs), in the thermoperiodic regulation of stem elongation in the short day plant (SDP) Begonia x hiemalis. Effects of GAs and some GA precursors were tested on plants grown under alternating day/night temperatures (DT/NT; 12/12 h), and the effects of these temperature regimes on endogenous plant hormones were analyzed using combined gas chromatography and mass spectrometry (GC-MS).Compared with constant temperatures (19/19 °C; 21/21 °C), stem elongation was significantly inhibited by low DT/high NT (14/24 °C; 18/24 °C) and enhanced by the opposite treatments (24/14 °C; 26/17 °C). GA1 stimulated elongation of internodes and petioles while ent-kaurene, kaurenoic acid, GA12, GA19, GA20 had no significant effect. The effect of GA1 was enhanced by a simultaneous application of calcium 3,5-dioxo-4-propionylcyclohexanecarboxylate (BX-112). BX-112 inhibited internode elongation at high DT/low NT (24/14 °C) but not at the reverse temperature regime.Gibberellins A53, A19, A20, A1, A4, A9, and indoleacetic acid (IAA), were identified by GC-MS from both leaves, including the petioles, and stems of B. x hiemalis. There were no apparent relationships between elongation of internodes and petioles and endogenous contents of gibberellins A53, A19, A20, and A1. Recoveries of deuterated GA4 and GA9 were generally too low for estimation of endogenous levels of these GAs.Constant temperature resulted in more open flowers and flower buds compared to alternating DT and NT. BX-112 decreased the time to anthesis.     

Understanding 3D structural complexity of individual Scots pine trees with different management history

Tree functional traits together with processes such as forest regeneration, growth, and mortality affect forest and tree structure. Forest management inherently impacts these processes. Moreover, forest structure, biodiversity, resilience, and carbon uptake can be sustained and enhanced with forest management activities. To assess structural complexity of individual trees, comprehensive and quantitative measures are needed, and they are often lacking for current forest management practices. Here, we utilized 3D information from individual Scots pine (Pinus sylvestris L.) trees obtained with terrestrial laser scanning to, first, assess effects of forest management on structural complexity of individual trees and, second, understand relationship between several tree attributes and structural complexity. We studied structural complexity of individual trees represented by a single scale‐independent metric called “box dimension.” This study aimed at identifying drivers affecting structural complexity of individual Scots pine trees in boreal forest conditions. The results showed that thinning increased structural complexity of individual Scots pine trees. Furthermore, we found a relationship between structural complexity and stem and crown size and shape as well as tree growth. Thus, it can be concluded that forest management affected structural complexity of individual Scots pine trees in managed boreal forests, and stem, crown, and growth attributes were identified as drivers of it.