Genome size is strongly linked to carbohydrate storage and weakly linked to root sprouting ability in herbs.

BACKGROUND AND AIMS: Several lines of evidence indicate that carbohydrate storage in plant below-ground organs might be positively related to genome size because both these plant properties represent resource sinks and can affect cell size, cell cycle time, water-use efficiency and plant growth. However, plants adapted to disturbance, such as root sprouters, could be an exception because their strategy would require higher carbohydrate reserves to fuel biomass production but small genomes to complete their cell cycles faster. METHODS: We used data from a field survey to test the relationship between genome size and the probability of root sprouting ability in 172 Central European herbaceous species. Additionally, we conducted a pot experiment with 19 herbaceous species with different sprouting ability (nine congeneric pairs plus one species), and measured root non-structural carbohydrate concentrations and pools at the end of a growing season. KEY RESULTS: In the Central European flora, the probability of root sprouting ability was lower in large-genome species but this pattern was weak. In the pot experiment, both total non-structural and water-soluble carbohydrates (mainly fructans) were positively and non-linearly related to genome size, regardless of sprouting strategy. The concentrations of mono- and disaccharides and all carbohydrate pools showed no link to genome size, and starch was absent in large-genome species. The link between genome size and carbohydrate storage was less apparent at a small phylogenetic scale because we only observed a higher carbohydrate concentration in species with larger genomes for four of the species pairs. CONCLUSIONS: Root sprouters may have smaller genomes because of their frequent occurrence in dry and open habitats. Large-genome species with presumably large cells and vacuoles could accumulate more water-soluble carbohydrates at the end of the growing season to fuel their growth and perhaps protect vulnerable organs from freezing early in the next season.

Herbs are not just small plants: What biomass allocation to rhizomes tells us about differences between trees and herbs.

PREMISE: Biomass accumulation over years in vertical stems of trees leads to hypoallometric scaling between stem and leaf biomass within this growth form, while for herbaceous species, biomass allocation between these organ types typically exhibits isometry. However, biomass accumulation in herbs can occur in belowground perennating organs (e.g., rhizomes) that are, contrary to aboveground parts of herbs, long-lived. Although ecologically important, biomass allocation and accumulation in rhizomes (and similar organs) have mostly not been studied. METHODS: We assembled data on biomass investments into plant organs for 111 rhizomatous herbs based on a literature survey and greenhouse experiment. We estimated the proportion of whole-plant biomass invested into rhizomes and, using allometric relationships, analyzed scaling between rhizome and leaf biomass and whether it is more variable than for other organs. RESULTS: On average, rhizomes comprise 30.2% of the total plant biomass. The proportion allocated to rhizomes does not change with plant size. Scaling between rhizome and leaf biomass is isometric, and allocation to rhizomes is not more variable than allocation to other organs. CONCLUSIONS: Rhizomatous herbs accumulate substantial biomass in rhizomes, and rhizome biomass scales isometrically with leaves, contrary to the hypoallometric relationship between stem and leaves in trees. This difference suggests that the rhizome biomass is in balance with aboveground biomass-a resource of carbon for rhizome formation that, at the same time, is dependent on carbon stored in rhizomes for its seasonal regrowth.

The impact of the COVID-19 pandemic on the health and working conditions of nurses and its implications for policies: a cross-sectional study in Slovakia.

BACKGROUND: Increased workload and of the health workforce (HW) strained the capacity to maintain essential health services (EHS) during the Coronavirus Disease 2019 (COVID-19) pandemic, while putting them at increased risk of COVID-19 and other consequences to their health. The aim of this study was to assess the impact of COVID-19 on the health, wellbeing, and working conditions of nurses in Slovakia and to identify gaps in policies to be addressed to increase preparedness of the HW for future emergencies. METHODS: A nation-wide cross-sectional study was conducted among nurses during November-December 2021, referring to the period of January 2021 to November 2021. To assess the differences between impact on HW on various levels of care, respondents were grouped by type of facility: hospital-COVID-19 wards; Hospital-non-covid ward; Outpatient or ER; Other care facilities. RESULTS: 1170 nurses participated, about 1/3 of them tested positive for COVID-19 by November 2021, mostly developing mild disease. Almost 2/3 reported long-covid symptoms and about 13% reported that they do not plan to get vaccinated against COVID-19. The median of the score of the impact of workload on health was 2.8 (56% of the maximum 5), the median score of mental health-wellbeing was 1.9 (63% of a maximum of 3). The studied impacts in all domains were highest in nurses working in COVID-19 hospital wards. Significant disruptions of health care were reported, with relatively high use of telemedicine to mitigate them. Overall, about 70% of the respondents thought of leaving their job, mostly due to working stress or inadequate pay. CONCLUSIONS: Our study showed that the COVID-19 pandemic poses a substantial burden on the health, wellbeing and working conditions of nurses in Slovakia and that a large proportion of nurses considered leaving their jobs because of work overload or low salaries. Human resource strategies should be adopted to attract, retain and continuously invest in HW development including in emergency preparedness and response. Such an approach may improve the resilience and preparedness of the health system in Slovakia for future emergencies.

What determines root-sprouting ability: Injury or phytohormones?

PREMISE: Root-sprouting (RS) is an evolutionarily independent alternative to axillary stem branching for a plant to attain its architecture. Root-sprouting plants are better adapted to disturbance than non-RS plants, and their vigor is frequently boosted by biomass removal. Nevertheless, RS plants are rarer than plants that are not root-sprouters, possibly because they must overcome developmental barriers such as intrinsic phytohormonal balance or because RS ability is conditioned by injury to the plant body. The objective of this study was to identify whether phytohormones or injury enable RS. METHODS: In a greenhouse experiment, growth variables, root respiration, and phytohormones were analyzed in two closely related clonal herbs that differ in RS ability (spontaneously RS Inula britannica and rhizomatous non-RS I. salicina) with and without severe biomass removal. RESULTS: As previously reported, I. britannica is a root-sprouter, but injury did not boost its RS ability. Root respiration did not differ between the two species and decreased continuously with time irrespectively of injury, but their phytohormone profiles differed significantly. In RS species, the auxins-to-cytokinins ratio was low, and injury further decreased it. CONCLUSIONS: This first attempt to test drivers behind different plant growth forms suggests that intrinsic phytohormone regulation, especially the auxins-to-cytokinins ratio, might be behind RS ability. Injury, causing a phytohormonal imbalance, seems to be less important in spontaneously RS species than expected for RS species in general.

Incorporating clonality into the plant ecology research agenda.

A longstanding research divide exists in plant ecology: either focusing on plant clonality, with no ambition to address nonclonal plants, or focusing on all plants, ignoring that many ecological processes can be affected by the fact that some plants are clonal while others are not. This gap cascades into a lack of distinction and knowledge about the similarities and differences between clonal and nonclonal plants. Here we aim to bridge this gap by identifying areas that would benefit from the incorporation of clonal growth into one integrated research platform: namely, response to productivity and disturbance, biotic interactions, and population dynamics. We are convinced that this will provide a roadmap to gain valuable insights into the ecoevolutionary dynamics relevant to all plants.

Strong impact of management regimes on rhizome biomass across Central European temperate grasslands.

Grassland ecosystems account for approximately 40% of terrestrial biomes globally. These communities are characterized by a large allocation to belowground biomass, often exceeding its aboveground counterpart. However, this biomass investment cannot be entirely attributed to the acquisitive function of roots. Grassland plants also allocate to non-acquisitive, stem-derived, belowground organs, such as rhizomes. These organs are responsible for the key plant functions of space occupancy, resprouting after damage, and seasonal rest. However, biomass investment to rhizomes has rarely been studied. Here we gathered community-level aboveground and rhizome biomass data for 52 temperate grasslands in Czech Republic (Central Europe), differing in management intensity. We found that rhizome biomass scaled linearly with aboveground biomass, and more intensive management disproportionally (negatively) affected rhizome biomass. This finding may have important implications for the persistence of temperate grassland plants and their provision of ecosystem services (e.g., soil carbon sequestration, soil stabilization) in relation to changing environments.

Young clonal and non-clonal herbs differ in growth strategy but not in aboveground biomass compensation after disturbance.

Clonal plants have more traits enabling individual persistence (larger belowground storage of buds and assimilates), whereas non-clonal plants have more traits enabling population persistence (a higher reliance on regeneration from seeds). This difference presumably makes those groups respond differently to disturbance. We asked whether this difference is already expressed in the first year of the plant's life. In a pot experiment with 17 congeneric pairs of clonal and non-clonal herbs, we investigated response to a disturbance at the individual level. We were interested whether the leaf C/N ratio (a proxy reflecting active growth and photosynthetic efficiency), the R/S ratio (a proxy for belowground storage) and the amount of compensated biomass differ between clonal and non-clonal herbs. Moreover, we asked whether compensation for the loss of aboveground biomass after disturbance can be predicted by the R/S ratio or explained by the leaf C/N ratio. We found that clonal herbs have higher leaf C/N and R/S ratios than non-clonal herbs. Under disturbance, the leaf C/N and R/S ratios decreased in the clonal herbs and increased in the non-clonal herbs. However, the clonal and non-clonal plants did not differ in biomass compensation ability. Neither the R/S ratio nor the leaf C/N ratio explained the compensation abilities of the herbs. These results show that even though the growth strategies of clonal and non-clonal plants and their reactions to disturbance are different, the groups are similarly capable of compensating for the loss of aboveground biomass. Clonal plants do not have an advantage over non-clonal plants under disturbance during their first year of life.

On Plant Modularity Traits: Functions and Challenges.

On-spot persistence, space occupancy, and recovery after damage are key plant functions largely understudied. Traits relevant to these functions are difficult to assess because of their relationships to plant modularity. We suggest that developing collection protocols for these traits is feasible and could facilitate their inclusion in global syntheses.

The effect of injury on whole-plant senescence: an experiment with two root-sprouting Barbarea species.

BACKGROUND AND AIMS: Senescence is the process of losing fitness when growing old, and is shaped by the trade-off between maintenance and reproduction that makes reproduction more unsure and maintenance more costly with age. In repeatedly reproducing plants, reductions in growth and fertility are signs of senescence. Disturbance, however, provides an opportunity to reset the ageing clock and consequently potentially ameliorate senescence. METHODS: To test the effects of disturbance on traits closely related to fitness and thus to senescence, a long-term garden experiment was established with two short-lived perennial congeners,Barbarea vulgaris and Barbarea stricta, that differ in their ability to resprout after injury. In the experiment, five damage treatments were applied to plants in four different phenophases. KEY RESULTS: It was found that damage to the plant body significantly prolonged life span in B. vulgaris but decreased whole-life seed production in both species. High concentration of seed production in one growing season characterized short life spans. Both more severe damage and a more advanced phenological phase at the time of damage caused reproduction to be spread over more than one growing season and equalized per-season seed production. In terms of seed quality, average weight of a single seed decreased and seed germination rate increased with age regardless of damage. CONCLUSIONS: Although disturbance is able to reset the ageing clock of plants, it is so harmful to plant fitness that resprouting serves, at best, only to alleviate slightly the signs of senescence. Thus, in terms of whole-life seed production, injured plants were not more successful than uninjured ones in the two studied species. Indeed, in these species, injury only slightly postponed or decelerated senescence and did not cause effective rejuvenation.

Enforced Clonality Confers a Fitness Advantage.

In largely clonal plants, splitting of a maternal plant into potentially independent plants (ramets) is usually spontaneous; however, such fragmentation also occurs in otherwise non-clonal species due to application of external force. This process might play an important yet largely overlooked role for otherwise non-clonal plants by providing a mechanism to regenerate after disturbance. Here, in a 5-year garden experiment on two short-lived, otherwise non-clonal species, Barbarea vulgaris and Barbarea stricta, we compared the fitness of plants fragmented by simulated disturbance ("enforced ramets") both with plants that contemporaneously originate in seed and with individuals unscathed by the disturbance event. Because the ability to regrow from fragments is related to plant age and stored reserves, we compared the effects of disturbance applied during three different ontogenetic stages of the plants. In B. vulgaris, enforced ramet fitness was higher than the measured fitness values of both uninjured plants and plants established from seed after the disturbance. This advantage decreased with increasing plant age at the time of fragmentation. In B. stricta, enforced ramet fitness was lower than or similar to fitness of uninjured plants and plants grown from seed. Our results likely reflect the habitat preferences of the study species, as B. vulgaris occurs in anthropogenic, disturbed habitats where body fragmentation is more probable and enforced clonality thus more advantageous than in the more natural habitats preferred by B. stricta. Generalizing from our results, we see that increased fitness yielded by enforced clonality would confer an evolutionary advantage in the face of disturbance, especially in habitats where a seed bank has not been formed, e.g., during invasion or colonization. Our results thus imply that enforced clonality should be taken into account when studying population dynamics and life strategies of otherwise non-clonal species in disturbed habitats.

Pain in Parkinson's Disease: A Cross-Sectional Study of Its Prevalence, Types, and Relationship to Depression and Quality of Life.

Pain is an important and distressing symptom in Parkinson's disease (PD). Our aim was to determine the prevalence of pain, its various types and characteristics, as well as its impact on depression and quality of life (QoL) in patients with PD. How pain differs in early- and advanced-stage PD and male and female PD patients was of special interest. One hundred PD patients on dopaminergic medications had a neurological examination and participated in a structured interview on pain characteristics and completed standardized questionnaires. A total of 76% of the patients had pain. The following types of pain were present: musculoskeletal pain accounted for 41% of the total pain, dystonic pain for 17%, central neuropathic pain for 22%, radicular pain for 27%, and other pains (non-radicular low back pain, arthritic, and visceral pain) made up 24%. One type of pain affected 29% of all the subjects, two types 35%, three types 10%, and four types of pain were reported by 2%. All types of pain were more prevalent in advanced-stage PD subjects than in early-stage PD subjects, except for arthritic pain (subclassified under"other pain"). The frequency and intensity of actual, average, and worst experienced pain were significantly more severe in advanced-stage subjects. PD subjects with general pain and in advanced stages were more depressed and had poorer QoL. Depression correlated with worst pain in the last 24 hours and with pain periodicity (the worst depression score in patients with constant pain). QoL correlated with average pain in the last 7 days. Pain is a frequent problem in PD patients, and it worsens during the course of the disease.

Nonmotor symptoms in early- and advanced-stage Parkinson's disease patients on dopaminergic therapy: how do they correlate with quality of life?

To determine the impact of nonmotor symptoms (NMS) on health-related quality of life (HRQoL) we examined 100 Parkinson's disease (PD) patients on dopaminergic medications. An "early-stage" (ES) and an "advanced-stage" (AS) groups were formed. HRQoL was established by the questionnaire PDQ-8, number of NMS by NMSQuest, and severity and frequency of NMS by the assessment scale NMSS. The total NMS averaged 11.3 (ES = 9.6, AS = 12.8). The NMSS domain correlation profiles for ES and AS did not fundamentally differ; however, the domains attention/memory and mood/apathy correlated moderately to strongly with HRQoL in ES, while the sleep/fatigue domain correlated moderately with HRQoL in AS. Weakly correlating domains were sleep/fatigue in ES and cardiovascular, attention/memory, and mood/apathy domains in AS. In view of these findings we strongly recommend systematic, active screening and therapy for neuropsychiatric disorders (mood, cognitive and sleep disorders, and fatigue) at the initial diagnosis and throughout the entire course of PD.

Impulse control disorders associated with dopaminergic medication in patients with pituitary adenomas.

OBJECTIVE: Impulse control disorders (ICDs) such as pathological gambling, compulsive shopping, compulsive eating, and hypersexuality are a matter of growing interest, especially in patients with Parkinson disease who are on dopamine replacement therapy. It was recently reported that ICDs are associated with other disorders also treated with dopaminergic drugs (dopamine agonists) such as restless legs syndrome, multiple system atrophy, progressive supranuclear palsy, and fibromyalgia. The aim of this study was to determine the prevalence of ICDs in patients with pituitary adenomas who take dopamine agonists (DAs). METHODS: Twenty consecutive patients with pituitary adenomas (mostly prolactinomas) taking DAs were assessed. All participated in a structured interview focused on ICDs, which was conducted by a physician. RESULTS: Two (10%) of 20 subjects had a condition diagnosed as ICD. The first patient is a 35-year-old man with giant macroprolactinoma who was alternately treated with different types of DAs (cabergoline, bromocriptine, and quinagolide). He developed compulsive eating and pathological gambling. The second patient is a 53-year-old man with macroprolactinoma who suffered from severe hypersexuality after cabergoline was begun. CONCLUSIONS: This study demonstrates the importance of systematic screening for ICDs in patients taking dopaminergic medication regardless of their primary condition.

Sweat: a potential marker of clinical activity in panic disorder.

OBJECTIVE: Panic disorder (PD) is a paroxysmal neuropsychiatric disorder with unclear etiology and obscure pathophysiology. Despite the frequency of its occurrence, PD still has no reliable laboratory markers. The sweat is a neglected human secrete reacting immediately to various neurovegetative challenges including psychic imupulses. We hypothesized a possible dysfunction of sweat homeosthasis in PD. SUBJECTS AND METHODS: 10 patients with active PD, 9 patients with PD in remission and 11 age-matched controls participated in this study. All subjects underwent a single 8-min session in the dry-heat sauna. Sweat and venous blood have been collected immediately after the end of this session. Concentrations of lactate, glucose, creatinine, natrium, potassium, chlorine, calcium and magnesium have been quantitatively estimated in both liquids and compared statistically among three groups. RESULTS: We did not find any significant difference in blood parameters of the three above groups. However, the patients with active PD had significantly higher sweat levels of lactate, glucose, creatinine and magnesium than both the other groups which did not differ. Moreover, sweat concentrations of natrium, potassium and chlorine were significantly higher in active PD comparing to the group of PD patients in remission. CONCLUSIONS: The sweat of patients with active PD in comparison to PD in its clinical remission exhibits surprisingly distinctive changes of selected parameters after dry-heat sauna exposure. Increased concentrations of lactate, glucose and magnesium in the sweat are not contradictory with presupposed neurotransmitter-metabolic firing mechanisms in PD. These findings appear to be perspective biochemical markers in PD and its course.

Shade avoidance in Trifolium repens: costs and benefits of plasticity in petiole length and leaf size.

We tested whether the degree of shade-induced plasticity in petiole length and leaf area is related to the mean trait value expressed under high-light conditions, and to what extent trait values expressed under high-light and shaded conditions affect plant performance. Thirty-four Trifolium repens genotypes were used with a wide range of petiole lengths and leaf areas. Plants were subjected to a high-light environment and two shading regimes: homogeneous shading and a vertical light gradient. Absolute petiole elongation in response to both shading treatments and absolute leaf area expansion in response to homogeneous shading were independent of the trait values expressed in high light. Consequently, relative plasticity was higher for genotypes with lower high-light trait values. Plasticity was associated with enhanced plant performance in a vertical light gradient but not in homogeneously shaded conditions. We also found costs associated with the ability to express plasticity. Our results suggest that selection can act separately on trait values expressed under high-light conditions and on the degree of plasticity.