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Contributions to Styrian Rubus-flora. -- In course of the 7th Austrian-Alpine Rubus workshop in Styria (2018) 38 Rubus species have been found. This is a substantial contribution to the Styrian and Austrian bramble flora. In addition, the knowledge of the general distribution of several Rubus species is considerably broadened. [ABSTRACT FROM AUTHOR]

NADPH oxidase 4 (Nox4) has recently been implicated as driving force in cellular senescence. Thus, there is growing interest to develop Nox4 inhibitors, which might be valuable agents for cosmeceutical applications. Alpine plants represent a valuable source for the identification of novel bioactive natural products with anti-ageing effects, especially substances that protect plants against UV radiation, which is also known to contribute to the ageing of human skin. Therefore, the aim of this study was to identify novel Nox4 inhibitors from alpine plants. Within an initial screening of extracts of alpine plants on their ability to inhibit Nox4 activity in HEK cells, the methanolic extract of the subaerial parts of Lycopus europaeus showed a strong inhibition of Nox4 (81% chemiluminescence quenching) and a simultaneously high cell viability (91% vitality). Rosmarinic acid was isolated and identified as the major compound in this bioactive extract. It showed a dose dependent inhibitory activity on Nox4 with an IC50 of 1 µM. Moreover, it also showed a significant inhibitory activity on Nox2 in the low micromolar range, whereas no inhibition of Nox5 was detected. Further investigations confirmed that the observed effects of rosmarinic acid on Nox2 and Nox4 are real inhibitory activities, and not due to ROS scavenging effects. Therefore, L. europaeus, which we demonstrated to be a good source of rosmarinic acid, has great potential for usage in cosmeceutical products with anti-ageing activity. [ABSTRACT FROM AUTHOR]

Solidago canadensis is an invasive species from North America that is spreading across Europe, Australia and temperate Asia. We hypothesized that the species' wide ecological amplitude is also based on its potential in hydraulic acclimation, and analyzed hydraulic and anatomical properties along a transect with decreasing soil humidity. Stem hydraulic conductivity, vulnerability to drought-induced embolism, stomatal closure during dehydration and xylem-anatomical parameters were quantified at three sites. At the humid site, specific hydraulic conductivity of stems (1.0 ± 0.2 kg m-1 MPa-1 s-1) was about twofold higher, and leaf-specific conductivity about 1.5 times higher (3.1 ± 0.5 kg m-1 MPa-1 s-1) than at the dry site. Water potential ( Ψ) at 50% loss of conductivity was −3.7 ± 0.1 MPa at the dry site and −3.1 ± 0.2 MPa at the humid site (September). Vulnerability to drought-induced embolism decreased along the transect and over the vegetation period. At drier sites, stomata started closing at lower Ψ while complete stomatal closure was reached at less negative Ψ (12% of maximum stomatal conductance: -2.5 ± 0.0 and −3.0 ± 0.2 MPa at the dry and humid site). The safety margin between stomatal closure and 50% loss of conductivity was 1.2 and 0.2 MPa at the dry and humid sites. The observed variability indicated an efficient acclimation in hydraulic conductivity and safety: plants at dry sites exhibited lower specific hydraulic conductivity, higher embolism resistance and broader safety margins, signifying a trade-off between the hydraulic safety and efficiency. The observed intraspecific plasticity in hydraulic and anatomical traits may help to explain the invasive potential of this species. [ABSTRACT FROM AUTHOR]

Abstract: Since the Roman time, the walnut tree (Juglans regia L.) has been cultivated in gardens and orchards in large parts of Europe, but only since Karl The Great (742–814) the walnut tree has been introduced to Tyrol (Austria) and other Alpine regions in Central Europe. As late as the beginning of the 20th century no wild populations but only cultivated trees are reported for inner Alpine valleys of Tyrol. Recently, however a striking increase of growing sites and individuals of J. regia has been detected within the Inn valley and other inner Alpine valleys of the Eastern Alps. In addition, climate warming, specifically milder winters since 1970 have been recorded within the study area (Innsbruck, Tyrol, Austria). Therefore, a dendroecological study at four study sites in surroundings of Innsbruck dominated by Scots pine (Pinus sylvestris L.) and/or Norway spruce (Picea abies (L.) Karst.) forests was initiated to examine more closely, if influence of climate warming favoured spread of this deciduous tree. Together, the four study sites encompassed 30ha, where in total 651 J. regia trees were analysed. Mapping of trees indicated that >90% grew on south and south-west-facing slopes. Evaluation of the age structure revealed that >48% of the analysed J. regia trees were younger than 10 years, >72% younger than 20 years and >92% younger than 30 years. Analysis of climate conditions in years of germination revealed a striking correspondence between the number of germinated trees and winter (December–February) minimum temperatures (; ) and the number of frost days (December–February) <−5°C (; ), which can be related to frost sensitivity during seedling stage. In summary, results of this study provide evidence that climate warming after 1970 favoured establishment of J. regia within this inner Alpine valley. [Copyright &y& Elsevier]