Climatic stresses limit plant growth and productivity. In the past decade, tree improvement programs were mainly focused on yield but it is obvious that enhanced stress resistance is also required. ...In this review we highlight important drought avoidance and tolerance mechanisms in forest trees. Genomes of economically important trees species with divergent resistance mechanisms can now be exploited to uncover the mechanistic basis of long-term drought adaptation at the whole plant level. Molecular tree physiology indicates that osmotic adjustment, antioxidative defense and increased water use efficiency are important targets for enhanced drought tolerance at the cellular and tissue level. Recent biotechnological approaches focused on overexpression of genes involved in stress sensing and signaling, such as the abscisic acid core pathway, and down-stream transcription factors. By this strategy, a suite of defense systems was recruited, generally enhancing drought and salt stress tolerance under laboratory conditions. However, field studies are still scarce. Under field conditions trees are exposed to combinations of stresses that vary in duration and magnitude. Variable stresses may overrule the positive effect achieved by engineering an individual defense pathway. To assess the usability of distinct modifications, large-scale experimental field studies in different environments are necessary. To optimize the balance between growth and defense, the use of stress-inducible promoters may be useful. Future improvement programs for drought resistance will benefit from a better understanding of the intricate networks that ameliorate molecular and ecological traits of forest trees.
Increasing salinity is one of the major drawbacks for plant growth. Besides the ion itself being toxic to plant cells, it greatly interferes with the supply of other macronutrients like potassium, ...calcium and magnesium. However, little is known about how sodium affects the translocation of these nutrients from the root to the shoot. The major driving force of this translocation process is thought to be the water flow through the xylem driven by transpiration. To dissect the effects of transpiration from those of salinity we compared salt stressed, ABA treated and combined salt- and ABA treated poplars with untreated controls. Salinity reduced the root content of major nutrients like K.sup.+, Ca.sup.2+ and Mg.sup.2+ . Less Ca.sup.2+ and Mg.sup.2+ in the roots resulted in reduced leaf Ca.sup.2+ and leaf Mg.sup.2+ levels due to reduced stomatal conductance and reduced transpiration. Interestingly, leaf K.sup.+ levels were positively affected in leaves under salt stress although there was less K.sup.+ in the roots under salt. In response to ABA, transpiration was also decreased and Mg.sup.2+ and Ca.sup.2+ levels decreased comparably to the salt stress treatment, while K.sup.+ levels were not affected. Thus, our results suggest that loading and retention of leaf K.sup.+ is enhanced under salt stress compared to merely transpiration driven cation supply.
Potassium (K(+)) channel function is fundamental to many physiological processes. However, components and mechanisms regulating the activity of plant K(+) channels remain poorly understood. Here, we ...show that the calcium (Ca(2+)) sensor CBL4 together with the interacting protein kinase CIPK6 modulates the activity and plasma membrane (PM) targeting of the K(+) channel AKT2 from Arabidopsis thaliana by mediating translocation of AKT2 to the PM in plant cells and enhancing AKT2 activity in oocytes. Accordingly, akt2, cbl4 and cipk6 mutants share similar developmental and delayed flowering phenotypes. Moreover, the isolated regulatory C-terminal domain of CIPK6 is sufficient for mediating CBL4- and Ca(2+)-dependent channel translocation from the endoplasmic reticulum membrane to the PM by a novel targeting pathway that is dependent on dual lipid modifications of CBL4 by myristoylation and palmitoylation. Thus, we describe a critical mechanism of ion-channel regulation where a Ca(2+) sensor modulates K(+) channel activity by promoting a kinase interaction-dependent but phosphorylation-independent translocation of the channel to the PM.
Tumor cells activate autophagy in response to chemotherapy-induced DNA damage as a survival program to cope with metabolic stress. Here, we provide in vitro and in vivo evidence that histone ...deacetylase (HDAC)10 promotes autophagy-mediated survival in neuroblastoma cells. We show that both knockdown and inhibition of HDAC10 effectively disrupted autophagy associated with sensitization to cytotoxic drug treatment in a panel of highly malignant V-MYC myelocytomatosis viral-related oncogene, neuroblastoma derived- amplified neuroblastoma cell lines, in contrast to nontransformed cells. HDAC10 depletion in neuroblastoma cells interrupted autophagic flux and induced accumulation of autophagosomes, lysosomes, and a prominent substrate of the autophagic degradation pathway, p62/sequestosome 1. Enforced HDAC10 expression protected neuroblastoma cells against doxorubicin treatment through interaction with heat shock protein 70 family proteins, causing their deacetylation. Conversely, heat shock protein 70/heat shock cognate 70 was acetylated in HDAC10-depleted cells. HDAC10 expression levels in high-risk neuroblastomas correlated with autophagy in gene-set analysis and predicted treatment success in patients with advanced stage 4 neuroblastomas. Our results demonstrate that HDAC10 protects cancer cells from cytotoxic agents by mediating autophagy and identify this HDAC isozyme as a druggable regulator of advanced-stage tumor cell survival. Moreover, these results propose a promising way to considerably improve treatment response in the neuroblastoma patient subgroup with the poorest outcome.
PurposeDue to both the new quality and intensity overtourism discussions have received, it is time to examine the question concerning the consequences this development has on destination level and ...how destinations can adjust their strategies for future development. This is especially important to consider, since overtourism can be seen as a fundamental issue for tourism development. First measures taken within destinations show that reactions are taking place, e.g. through access restrictions of frequently visited places. The purpose of this paper is to identify future-oriented strategies and to derive concrete measures in order to deal with overtourism on a destination level.Design/methodology/approachIn total, 19 qualitative interviews with European destination managers were conducted and evaluated via the qualitative analysis method GABEK® with WinRelan® software.FindingsThe results show that various stakeholders are involved in overtourism, with the destination management organization being the central actor to deal with issues. It is challenging to choose between different strategies and measures, which always have to be considered in relation to the specific conditions of a destination and the perception level of overtourism. In order to face current developments, the initiation of a stakeholder dialog can be seen as a promising factor, but also as a challenging task.Originality/valueCurrently, a “wait-and-see-attitude” exists, where well-known destinations are cited as negative examples, but a serious examination related to one’s own destination has not yet been developed. This consideration should be seen as a prerequisite for future-oriented destination development, which takes the local population into account.
Coronins belong to the superfamily of the eukaryotic-specific WD40-repeat proteins and play a role in several actin-dependent processes like cytokinesis, cell motility, phagocytosis, and vesicular ...trafficking. Two major types of coronins are known: First, the short coronins consisting of an N-terminal coronin domain, a unique region and a short coiled-coil region, and secondly the tandem coronins comprising two coronin domains.
723 coronin proteins from 358 species have been identified by analyzing the whole-genome assemblies of all available sequenced eukaryotes (March 2011). The organisms analyzed represent most eukaryotic kingdoms but also cover every taxon several times to provide a better statistical sampling. The phylogenetic tree of the coronin domains based on the Bayesian method is in accordance with the most recent grouping of the major kingdoms of the eukaryotes and also with the grouping of more recently separated branches. Based on this "holistic" approach the coronins group into four classes: class-1 (Type I) and class-2 (Type II) are metazoan/choanoflagellate specific classes, class-3 contains the tandem-coronins (Type III), and the new class-4 represents the coronins fused to villin (Type IV). Short coronins from non-metazoans are equally related to class-1 and class-2 coronins and thus remain unclassified.
The coronin class distribution suggests that the last common eukaryotic ancestor possessed a single and a tandem-coronin, and most probably a class-4 coronin of which homologs have been identified in Excavata and Opisthokonts although most of these species subsequently lost the class-4 homolog. The most ancient short coronin already contained the trimerization motif in the coiled-coil domain.
Purpose
The corporate reputation of a firm and reputation risk is becoming increasingly important because of the rise of social media and the ongoing globalization. While defining and measuring ...corporate reputation and reputation risk represent the first steps in corporate reputation (risk) management, there is no general agreement in defining and measuring these two terms. Hence, this paper aims to give an overview of the existing literature in this regard, discuss it with respect to the operability in corporate reputation (risk) management and, based on this, present a holistic and consistent approach to define and measure corporate reputation and reputation risk.
Design/methodology/approach
The paper gives an overview of the literature regarding definitions and measurement methods of corporate reputation and reputation risk. Moreover, it discusses such definitions and measurement methods with respect to the operability in corporate reputation (risk) management.
Findings
Based on an overview of the literature regarding definitions and measurement methods of corporate reputation and reputation risk, the authors present a holistic and consistent approach to define and measure corporate reputation and reputation risk.
Originality/value
The authors present an holistic and consistent approach to define and measure corporate reputation and reputation risk with focus on (risk) management purposes.
Understanding the atmospheric conditions in remote areas contributes to assessing local weather phenomena. Obtaining vertical profiles of the atmosphere in isolated locations can introduce ...significant challenges for the deployment and maintenance of equipment, as well as regulatory obstacles. Here, we assessed the potential of consumer drones equipped with lightweight atmospheric sensors to collect vertical meteorological profiles off One Tree Island (Great Barrier Reef), located approximately 85 km off the east coast of Australia. We used a DJI Matrice 300 drone with two InterMet Systems iMet-XQ2 UAV sensors, capturing data on atmospheric pressure, temperature, relative humidity, and wind up to an altitude of 1500 m. These flights were conducted three times per day (9 a.m., 12 noon, and 3 p.m.) and compared against ground-based weather sensors. Over the Austral summer/autumn, we completed 72 flights, obtaining 24 complete sets of daily measurements of atmospheric characteristics over the entire vertical profile. On average, the atmospheric temperature and dewpoint temperature were significantly influenced by the time of sampling, and also varied among days. The mean daily temperature and dewpoint temperature reached their peaks at 3 p.m., with the temperature gradually rising from its morning low. The mean dewpoint temperature obtained its lowest point around noon. We also observed wind speed variations, but changes in patterns throughout the day were much less consistent. The drone-mounted atmospheric sensors exhibited a consistent warm bias in temperature compared to the reference weather station. Relative humidity showed greater variability with no clear bias pattern, indicating potential limitations in the humidity sensor’s performance. Microscale temperature inversions were prevalent around 1000 m, peaking around noon and present in approximately 27% of the profiles. Overall, the drone-based vertical profiles helped characterise atmospheric dynamics around One Tree Island Reef and demonstrated the utility of consumer drones in providing cost-effective meteorological information in remote, environmentally sensitive areas.
Wood, also designated as secondary xylem, is the major structure that gives trees and other woody plants stability for upright growth and maintains the water supply from the roots to all other plant ...tissues. Over recent decades, our understanding of the cellular processes of wood formation (xylogenesis) has substantially increased. Plants as sessile organisms face a multitude of abiotic stresses, e.g., heat, drought, salinity and limiting nutrient availability that require them to adjust their wood structure to maintain stability and water conductivity. Because of global climate change, more drastic and sudden changes in temperature and longer periods without precipitation are expected to impact tree productivity in the near future. Thus, it is essential to understand the process of wood formation in trees under stress. Many traits, such as vessel frequency and size, fiber thickness and density change in response to different environmental stimuli. Here, we provide an overview of our current understanding of how abiotic stress factors affect wood formation on the molecular level focussing on the genes that have been identified in these processes.
PDF
