Biomass of speckled alder on an air-polluted mountain site and its response to fertilization.

The article summarizes outcomes of a biomass study conducted in a young speckled alder plantation on a cold mountain site. At this location, the previously existing old forest was clear felled because of damage from air pollution, and present-day surface humus is in need of restoration. The intention of this study was to quantify the biomass and nutrients accumulated by alders and their components and assess whether the initial fertilization resulted in increased biomass production and nutrient accumulation in the biomass. Besides the control, two fertilized treatments were installed. In the surface treatment (SUT), the amendment was applied as a base dressing in small circles around trees. In the planting-hole treatment (PHT), the amendment was incorporated into soil inside the planting holes. Five growth seasons after planting and fertilization, six alders from each treatment were harvested including roots. Their biomass was quantified and analyzed for macroelements. The greatest pool of dry mass (DM) was branches in the control and stem wood in the fertilized treatments. The greatest pools of macroelements were leaves and branches. The most pronounced effects of fertilization were recorded in the DM and consequently in the absolute quantities of nutrients. The DM of an average tree in the control, SUT, and PHT was 85, 226, and 231 g, respectively. The absolute contents of nutrients per tree in the fertilized treatments showed the following increases, as compared with the control: (N) 2.5-2.6 times; (P) 1.6-2.4 times; (K) 1.8-2.1 times; and (Mg) 1.8-2.0 times, respectively. Speckled alder responded positively to fertilization.

Biochemical Responses in Populus tremula: Defending against Sucking and Leaf-Chewing Insect Herbivores.

The main biochemical traits were estimated in poplar leaves under biotic attack (aphids and spongy moth infestation). Changes in the abundance of bioactive compounds in genetically uniform individuals of European aspen (Populus tremula), such as proline, polyphenolic compounds, chlorophylls a and b, and volatile compounds, were determined between leaves damaged by sucking insects (aphid-Chaitophorus nassonowi) and chewing insects (spongy moth-Lymantria dispar) compared to uninfected leaves. Among the nine analyzed phenolic compounds, only catechin and procyanidin showed significant differences between the control leaves and leaves affected by spongy moths or aphids. GC-TOF-MS volatile metabolome analysis showed the clear separation of the control versus aphids-infested and moth-infested leaves. In total, the compounds that proved to have the highest explanatory power for aphid-infested leaves were 3-hexenal and 5-methyl-2-furanone, and for moth-infested leaves, trans-α-farnesene and 4-cyanocyclohexane. The aphid-infested leaves contained around half the amount of chlorophylls and twice the amount of proline compared to uninfected leaves, and these results evidenced that aphids influence plant physiology more than chewing insects.

Shifts in intra-annual growth dynamics drive a decline in productivity of temperate trees in Central European forest under warmer climate.

Climate change shifts tree growth phenology and dynamics in temperate forests. However, there is still little information on how warming climate changes intra-annual growth patterns and how these changes affect the productivity and carbon uptake of temperate trees. To address this knowledge gap, we used high-precision growth data from automatic dendrometers to quantify the impacts of unusually warm weather in 2022 (hot year) on growth phenology, dynamics and aboveground biomass (AGB) production in eight common temperate species (both conifers and broadleaved) in the Czech Republic. Mixed-effect models were used to investigate inter-annual changes in the start, end, and length of the growing season and intra-annual growth dynamics. We also modelled how changes in growth phenology, growth rates, and tree size affected yearly AGB production of individual trees. In the hot year, the growth started 5 days earlier, peaked 22 days earlier and ended 20 days earlier than in the climatically normal year, resulting in a shorter growing season with fewer growing days. AGB production decreased 36 % in the hot year, mainly due to fewer growing days and lower maximum growth rates, but with significant variation among tested species. The decline in AGB production in the hot year was most significant in the most productive species, which were also the species with the greatest reduction in the number of growing days. Tree size strongly enhanced AGB production, but its effect did not change with climate variation. Our findings suggest that climate change is likely to advance but also shorten the growing season of temperate trees, resulting in lower biomass production and carbon uptake. The results also indicate that the fast-growing and highly productive temperate tree species will have their growth reduced most by climate change, which will increasingly limit their high carbon sequestration potential.

Proteomic responses of two spring wheat cultivars to the combined water deficit and aphid (Metopolophium dirhodum) treatments.

In the field, plants usually have to face the combined effects of abiotic and biotic stresses. In our study, two spring wheat cultivars-Septima and Quintus-were subjected to three water regimes [70%, 50%, and 40% soil water capacity (SWC)], aphid (Metopolophium dirhodum) infestation, or the combination of both stresses, i.e., water deficit (50%, 40% SWC) and aphids. The study has a 2 × 3 × 2 factorial design with three biological replicates. In the present study, the results of proteomic analysis using 2D-DIGE followed by MALDI-TOF/TOF protein identification are presented. Water deficit but also aphid infestation led to alterations in 113 protein spots including proteins assigned to a variety of biological processes ranging from signaling via energy metabolism, redox regulation, and stress and defense responses to secondary metabolism indicating a long-term adaptation to adverse conditions. The absence of specific proteins involved in plant response to herbivorous insects indicates a loss of resistance to aphids in modern wheat cultivars during the breeding process and is in accordance with the "plant vigor hypothesis." Septima revealed enhanced tolerance with respect to Quintus as indicated by higher values of morphophysiological characteristics (fresh aboveground biomass, leaf length, osmotic potential per full water saturation) and relative abundance of proteins involved in mitochondrial respiration and ATP biosynthesis.

Relationship between WCS120 Protein Family Accumulation and Frost Tolerance in Wheat Cultivars Grown under Different Temperature Treatments.

Frost tolerance (FT) is generally acquired after exposure of plants to low, but non-freezing temperatures, where it is associated with the accumulation of COR proteins. The aim of the study was to reveal the effect of different temperature treatments (25, 17, 9 and 4 °C) on accumulation of cold-regulated dehydrins, dry weight content, and the development of FT in five wheat cultivars of different frost-tolerances in detail. The levels of cold-regulated dehydrins, WCS120 proteins in wheat were determined by immunoblot analysis, probed with an anti-dehydrin antibody. The lower the growth temperature: the higher the level of frost tolerance, dry weight content, and dehydrin accumulation, in all cultivars. There was a significant correlation between the level of induced FT and the accumulation of WCS120 proteins in cultivars grown at lower temperatures (9 and 4 °C). Moreover, the highly frost-tolerant wheat cultivars (as opposed to the lower-tolerant) accumulated higher levels of WCS120 proteins at 17 °C, a temperature at which it was not possible to differentiate between them via a frost test. Here, we demonstrated the possibility to distinguish differently frost-tolerant cultivars grown at different temperatures by the accumulation of different members of WCS120 family.

Is Betula carpatica genetically distinctive? A morphometric, cytometric and molecular study of birches in the Bohemian Massif with a focus on Carpathian birch.

Until recently, Czech taxonomists often treated Betula carpatica as a distinct species. Several morphological traits for distinguishing B. carpatica from B. pubescens or other birches are described in literature; however, it has been proven impossible to reliably identify B. carpatica in the field. With the use of morphological and molecular approaches, we intended to assess the position of B. carpatica in the context of other birch taxa reported from the Bohemian Massif and to find more reliable morphological traits for their identification. In our dataset, we distinguished the following birch taxa referred to in the recent Czech literature: B. pendula, B. pubescens, B. carpatica, B. oycoviensis, B. nana, B. petraea and B. ×seideliana. We complemented them with triploids and several diploid and tetraploid "working units" into which we included intermediate individuals that in terms of morphology did not unambiguously match any of the abovementioned birch taxa. Holoploid genome size was measured to determine the ploidy level. To identify genetic relationships between selected taxa and "working units", microsatellite analyses were performed. Model-based STRUCTURE analysis together with principal coordinates analysis (PCoA) based on genetic distances was performed to identify the similarities in multilocus genotype data between groups distinguished in the dataset. The applied analyses were not able clearly to distinguish any group among tetraploid individuals. In this light, it was of no use to search for any more reliable morphological traits of B. carpatica and also B. petraea. Among diploids, B. nana was always distinguished, in contrast to B. oycoviensis, which was not genetically recognized despite being usually morphologically distinct. Based on our results and a literature review, we suggest that B. carpatica and also the closely similar B. petraea should not be considered separate species. A similar conclusion seems relevant also for B. oycoviensis; however, further verification is desirable in this case.

Quantitative analysis of proteome extracted from barley crowns grown under different drought conditions.

Barley cultivar Amulet was used to study the quantitative proteome changes through different drought conditions utilizing two-dimensional difference gel electrophoresis (2D-DIGE). Plants were cultivated for 10 days under different drought conditions. To obtain control and differentially drought-treated plants, the soil water content was kept at 65, 35, and 30% of soil water capacity (SWC), respectively. Osmotic potential, water saturation deficit, (13)C discrimination, and dehydrin accumulation were monitored during sampling of the crowns for proteome analysis. Analysis of the 2D-DIGE gels revealed 105 differentially abundant spots; most were differentially abundant between the controls and drought-treated plants, and 25 spots displayed changes between both drought conditions. Seventy-six protein spots were successfully identified by tandem mass spectrometry. The most frequent functional categories of the identified proteins can be put into the groups of: stress-associated proteins, amino acid metabolism, carbohydrate metabolism, as well as DNA and RNA regulation and processing. Their possible role in the response of barley to drought stress is discussed. Our study has shown that under drought conditions barley cv. Amulet decreased its growth and developmental rates, displayed a shift from aerobic to anaerobic metabolism, and exhibited increased levels of several protective proteins. Comparison of the two drought treatments revealed plant acclimation to milder drought (35% SWC); but plant damage under more severe drought treatment (30% SWC). The results obtained revealed that cv. Amulet is sensitive to drought stress. Additionally, four spots revealing a continuous and significant increase with decreasing SWC (UDP-glucose 6-dehydrogenase, glutathione peroxidase, and two non-identified) could be good candidates for testing of their protein phenotyping capacity together with proteins that were significantly distinguished in both drought treatments.