Inspecting the differences in mechanical resistance between flowers and leaves by multiple mechanical testing and calibration methods.

Earthworms, Lumbricus terrestris, exposed for 96 h to filter paper saturated with five nominal concentrations of pentachlorophenol (PCP: 5–50 μg PCP/cm2), exhibited a 50% lethal concentration (LC50) of 25.0 μg PCP/cm2 (95% confidence interval [CI]: 22.8–27.2) and corresponding whole worm body burden-based 50% lethal dose (LD50) of 877.7 μg PCP/g dry mass (95% CI: 828.5–927.0). Linear regression modeling showed that worms increased body concentrations (BC = μg PCP/g dry tissue mass) with increasing exposure concentrations (EC) according to BC = 113.5 + 29.5EC (r2 = 0.94, p = 0.03). Phagocytosis of yeast cells by immunoactive coelomocytes was suppressed only at body concentrations (863.3 μg PCP/g dry mass) that approximated the calculated LD50 and overlapped those demonstrating lethality, indicating a sharp transition between sublethal and lethal toxicity. An exposure concentration of 15 μg PCP/cm2 produced significant suppression of phagocytosis of yeast cells by immunoactive coelomocytes. However, the average measured body burden from this group (863.3 μg PCP/g dry mass) approximated the estimated LD50, indicating a sharp toxic response slope. Exposure to 10 μg PCP/cm2 with a corresponding body concentration of 501.3 μg PCP/g dry mass did not affect phagocytosis. The importance of body burden data is emphasized.

Quillay (Quillaja saponaria Molina) and peumo (Cryptocarya alba [Molina] Looser) are two tree species endemic to Chile that grow in Mediterranean climate zones, characterized by a summer season with high temperatures, high solar radiation, and low soil water availability. A study was conducted with 2-year-old Q. saponaria and C. alba plants and two substrate water conditions: well-watered and controlled water restriction. At the end of the study, anatomical leaf modifications were analyzed. The tissues were anatomically described in transverse sections of juvenile and adult leaves, measuring leaf thickness, cuticle thickness, and cell density of the mesophyll parenchymal tissues. In the young leaves of Q. saponaria plants undergoing water restriction treatment, an increase in cuticle and leaf thickness and a decrease in the density of the palisade and spongy parenchyma were observed. In contrast, a significant reduction in leaf thickness was observed in adult leaves of both species with water restriction treatment. The anatomical changes in the leaves of Q. saponaria and C. alba suggest an adaptation to adverse environmental conditions, such as water restriction.

BackgroundAgainst the background of a changing climate, the responses of functional traits of plateau wetland plants to increasing temperatures and CO2 concentrations need to be understood. Hydraulic traits are the key for plants to maintain their ecological functions and affect their growth and survival. However, few studies have comprehensively considered the response strategies of wetland plants' hydraulic traits to environmental changes in the context of water and matter transport, loss, and retention. According to the latest IPCC prediction results, we performed experiments under increased temperature (2 °C) and CO2 levels (850 μmol/mol) in an artificial Sealed-top Chamber (STC) to investigate the responses of the hydraulic characteristics of Schoenoplectus tabernaemontani, the dominant species in plateau wetlands in China.ResultsCompared with the CK group, net photosynthetic rate, transpiration rate, stomatal length, cuticle thickness, vascular bundle length, vascular bundle width, and vascular bundle area of S. tabernaemontani in the ET group were significantly reduced, whereas stomatal density and vein density increased significantly. Compared with the CK group, the hydraulic traits of S. tabernaemontani in the EC group were reduced considerably in stomatal length and cuticle thickness but increased dramatically in stomatal density, and there were no significant differences between other parameter values and the control group. Net photosynthetic rate was significantly positively correlated with stomatal length, cuticle thickness, and vascular bundle length, and stomatal conductance was significantly positively correlated with cuticle thickness. The transpiration rate was significantly positively correlated with cuticle thickness, epidermal cell area, vascular bundle length, vascular bundle width, and vascular bundle area. Regarding the hydraulic traits, there was a significant negative correlation between stomatal density and stomatal length, or cuticle thickness, and a significant positive correlation between the latter two. The epidermal cell area was significantly positively correlated with epidermal thickness, vascular bundle length, vascular bundle width, and vascular bundle area.ConclusionsIncreased temperature and CO2 levels are not conducive to the photosynthetic activity of S. tabernaemontani. Photosynthetic rate, stomatal density and size, vein density, epidermal structure size, and vascular bundle size play an essential role in the adaptation of this species to changes in temperature and CO2 concentration. In the process of adaptation, hydraulic traits are not isolated from each other, and there is a functional association among traits. This study provide a scientific basis for the management and protection of plateau wetlands.

In this study, Alhagi sparsifolia Shap. was used to test the hypothesis that leaf economic and hydraulic traits are coupled in plants in a hyper-arid region. Five economic traits and six hydraulic traits were examined to explore the relationship. Results showed that the stomatal density (SD) on both surfaces was coupled with maximum stomatal conductance to water vapor (gwmax) and leaf tissue density (TD). SD on adaxial surface (SDaba) was significantly positively related to vein density (VD) but negatively related to leaf thickness (LT) and stomatal length on adaxial surface (SLada). Nitrogen concentration based on mass (Nmass) was significantly negatively correlated with leaf mass per area (LMA), LT, and VD, whereas nitrogen concentration based on area (Narea) was significantly positively related to LMA and TD. Mean annual precipitation (MAP) contributed the most to the changes in LT and stomatal length (SL). Soil salt contributed the most to TD, SD, and gwmax. Soli nutrients influenced the most of LMA and VD. Mean annual temperature contributed the most to Nmass and Narea. In conclusion, the economics of leaves coupled with their hydraulic traits provides an economical and efficient strategy to adapt to the harsh environment in hyper-arid regions.

Exploring the response of leaf anatomical structure to climate warming is helpful for understanding the adaptive mechanisms of trees to climate change. We conducted a warming experiment by transplanting seedlings of Larix gmelinii from 11 provenances to two common gardens, and examined the response of leaf anatomical structure to climate warming. The results showed that warming significantly increased leaf thickness (TL), upper epidermal mesophyll thickness (TUEM), lower epidermal mesophyll thickness (TLEM), endodermal thickness (TE), vascular bundle diameter (DVB), transfer tissue thickness (TTT), and the percentage of mesophyll thickness to TL(PMT), and significantly decreased the upper epidermal thickness (TUE) and the percentage of epidermal thickness to TL (PE). The mesophyll thickness was positively associated with chlorophyll concentration and maximum net photosynthetic rate. The responses of TL, TUEM, TLEM, TE, DVB, TTT, TUE, PMT and PE to warming differed among all the provenances.As the aridity index of the original site increased, the magnitude of the warming treatment's effect decreased for TL, TUEM, TLEM, TTT and PMT, and increased for TUE and PE. Warming increased the thickness and proportion of profit tissue (e.g., mesophyll) and decreased the thickness and proportion of defensive tissue (e.g., epidermis), and those changes varied among provenances. L. gmelinii could adapt to climate warming by adjusting leaf anatomical structure, and this ability was weak for trees from provenance with high aridity index.

P7. A multidisciplinary onco-plastic approach for management of chest wall tumours

We examined differences in net photosynthetic rate (PN), transpiration rate (E), water use efficiency (WUE), ratio of substomatal to atmospheric CO2 concentration (Ci/Ca), cuticle thickness (CT), epidermis cell size (ECS), mesophyll cell size (MCS), vascular bundle size (VBS), tissue density (TD), and coefficient of water loss (k) in Sabina vulgaris as related to sex, shoot form, and leaf form. PN, E, WUE, Ci/Ca, MCS, VBS, and k varied with sex, whereas CT, ECS, and TD did not. These differences in physiology and anatomy between the female and male plants may be closely related with their reproduction behaviour. PN, E, Ci/Ca, CT, ECS, MCS, and VBS were significantly smaller in the erect shoots than in the prostrate shoots, WUE was just opposite; TD and k did not vary with shoot form. These changes in physiology with shoot form indicate that erect shoots may be more tolerant of water stress than prostrate shoots. PN, E, Ci/Ca, TD, and k were significantly greater in the spine leaves than in the scale leaves, whereas WUE, CT, ECS, MCS, and VBS followed the opposite trends. The changes in physiology and anatomy with leaf form suggest that scale leaves have higher drought-resistant and water-holding capacities than spine leaves. Measurements of field gas exchange showed that three-year-old seedlings had lower drought-resistance and higher water loss than five-year-old seedlings, which provides some evidence that seedling survival decreases with decreasing plant age.

The physiological and anatomical impact of field dodder (Cuscuta campestris Yunck.) on alfalfa and sugar beet was examined under controlled conditions. The following parameters were checked: physiological — content of pigments (chlorophyll a, chlorophyll b, and carotenoids) and mineral nutrients: nitrogen, phosphorus, potassium, and percent of organic and mineral nutrients; and anatomical — thickness of the epidermis and cortex, diameter of the stem and central cylinder of alfalfa plants, diameter of tracheids and phloem cells, area of xylem and phloem, and hydraulic conductance of petiole bundles in petiole vascular bundles of sugar beet plants. Leaf parameters were also measured on both host plants: thickness of upper and underside leaf epidermis, thickness of palisade, spongy and mesophyll tissue, and diameter of vascular bundle cells. Pigments content and anatomical parameters were measured 7, 14, 21, 28, 35, and 42 d after infestation (DAI), while mineral nutrient contents were determined 20 and 40 DAI. Field dodder caused a significant reduction in pigments content in infested alfalfa (15%–68%) and sugar beet plants (1%–54%). The results obtained in this study confirmed that this parasitic flowering plant has a strong effect on most anatomical parameters of the stem and leaf of alfalfa and leaf and petiole of sugar beet. Also, it was revealed that field dodder increased the contents of N, P2O5, K2O, and organic nutrients in infested alfalfa plants, while infested sugar beet plants had higher contents of N and organic nutrients compared with non-infested plants.

The effects of field dodder on the anatomical changes in alfalfa plants were examined under controlled conditions. Experiment included the following variants: non-infested alfalfa plants (control); infested alfalfa plants (untreated) and infested plants treated with propizamyde. Propizamyde application rates were 3000 g A.I. ha-1 and 4000 g A.I. ha-1. The following anatomical parameters were analysed: 1) stem - thickness of epidermis and cortex, diameter of stem and central cylinder; 2) leaf - thickness of adaxial and abaxial epidermis, thickness of parenchyma and spongy tissue, thickness of mesophyll and the diameter of the bundle sheath cells. Plants infested by field dodder had lower values of the majority of anatomical parameters, compared to non-infested plants. Reductions in the last assessment ranged from 34% to 51% for stem and 27% - 51% for leaf. Anatomical parameters of alfalfa stems and leaves had significantly higher values in non-infested plants and infested plants treated with propizamyde.

Comparison between high-frequency ultrasonography and histological assessment reveals weak correlation for measurements of scar tissue thickness

The field experiment had been conducted in the Lath-house in the college of Agriculture , Anbar University by planting Solanum melongena L. Black beauty during agricultural season of 2010. Seedlings were distributed randomly according to complete randomized design (CRD) . The four concentrations of urea dissolved in distill water . The levels of urea were control (N0) ; 0.5 g/L(N1) ;1 g/L(N2);8 g/L(N3) . After 40 days of transplanting Eggplants were sprayed four times by urea concentrations . Anatomic study of cross-sections of root showed clear reduction in thickness of Epidermis, cortex and xylem tissues of plants treated with the concentration 8 gram urea/L where thickness of these tissues was 26.07 µm, 178.52 µm, 37.60 µm respectively. The phloem showed 224.32 um thickness. It was the highest among other treatments especially the treatment 1g urea/L which showed higher rate of xylem thickness of 373.68 µm. The cross-section of stem also showed clear difference in the epidermis thickness for all treated plants. In addition, 1gram urea/L showed higher cortex thickness of the stem,( 432.93 µm). Increasing urea concentration to 8 gram/L lead to reduce xylem thickness (104.72 µm) and decreasing pith thickness in the same treatment rated 426.67 µm. Plants treated with 1 gram urea/L, show increasing in the phloem and the pith thickness of 98.62 µm, 577.47µm rate respectively.The study showed that stoma distribution in the surface of leaves is of Anomocytic type with clear reduction of the outer epidermis thickness of 1gram urea/L treatment rated 16.05µm. This treatment showed highest rate in palasid tissues 98.40. The N2 treatment shows higher rate in stoma frequency on the upper and lower surfaces, 10 stoma/ml². The N3 treatment shows less number of stoma on the upper and lower surfaces, 6.04 stoma/ml². As for cell length in the two epidermis, the N2 treatment shows clear increase rated 59.08 in comparison with control treatment and othertreatments.

Leaf economic, hydraulic, and anatomical traits play crucial roles in plant adaptation to diverse and variable environments. However, their relationships at the intraspecific level remain unclear. In this study, we investigated Quercus variabilis, a species spanning temperate to subtropical zones, to assess functional trait variation along a north-to-south environmental gradient in China (24°94′–40°26′ N). We analyzed ten key functional traits, including leaf mass per area (LMA), leaf thickness (LT), leaf tissue density (LTD), leaf nitrogen concentration (LN), stomatal density (SD), vein density (VD), stomatal guard cell length (SL), palisade tissue thickness (PT), spongy tissue thickness (ST), and palisade-to-spongy tissue ratio (PT/ST) across nine natural populations. The results showed that Q. variabilis exhibited significant plasticity in functional trait variation, primarily driven by environmental factors, with mean annual precipitation (MAP) and soil total nitrogen (STN) emerged as key ecological drivers promoting the coordinated variation in leaf functional traits. Coordinated relationships were observed between leaf economic traits (LMA, LT, LTD, LN) and hydraulic traits (SD, VD, SL), which varied in response to environmental conditions. Furthermore, leaf anatomical traits (PT, ST, PT/ST) were closely linked to both hydraulic and economic traits. These findings provide valuable insights into the adaptive strategies of Q. variabilis and enhance our understanding of plant responses to environmental change at the intraspecific level.

Floral longevity (FL) is an important floral functional trait which is critical for flowering plants. FL shows great diversity among angiosperms; however, there is limited information on the mechanisms that influence differences in floral longevity, especially the relationship between petal anatomical traits and floral longevity. We aimed to examine (1) the relationships between petal anatomical traits and FL in tree peony cultivars and (2) the petal anatomical characteristics of longer FL cultivars. Eleven traits of six tree peony cultivars with different FL were investigated, including six water conservation traits (petal thickness, cuticle thickness, number of cell layers, mesophyll thickness, adaxial epidermis thickness and abaxial epidermis thickness), three water supply traits (vein density, number of xlylem vessels and xylem vessel diameter), petal fresh mass and petal dry mass across cultivars. There are significant differences in traits related to water conservation and water supply ability of tree peonies with different FL. Tree peony cultivars with long FL were characterized by the thicker Mesophyll, cuticles, adaxial and abaxial epidermis of the petals. There was a positive correlation between FL and vessel number and vessel diameter. These results suggest that the ability to retain water in flowers is associated with floral longevity. Petal traits related to water conservation and supply, including vein densities, mesophyll thickness, and epidermis thickness, are beneficial for prolonging the flower longevity in tree peonies.

Water availability is a key environmental factor affecting plant species distribution, and the relationships between hydraulic and economic traits are important for understanding the species’ distribution patterns. However, in the same community type but within different soil water availabilities, the relationships in congeneric species remain ambiguous. In northwest China, Quercus wutaishanica forests in the Qinling Mountains (QM, humid region) and Loess Plateau (LP, drought region) have different species composition owing to contrasting soil water availability, but with common species occurring in two regions. We analyzed eight hydraulic traits [stomatal density (SD), vein density (VD), wood specific gravity (WSGbranch), lower leaf area: sapwood area (Al: As), stomatal length (SL), turgor loss point (ΨTlp), maximum vessel diameter (Vdmax) and height (Height)] and five economic traits [leaf dry matter content (LDMC), leaf tissue density (TD), leaf dry mass per area (LMA), Leaf thickness (LT) and maximum net photosynthetic rate (Pmax)] of congeneric species (including common species and endemic species) in Q. wutaishanica forests of QM and LP. We explored whether the congeneric species have different economic and hydraulic traits across regions. And whether the relationship between hydraulic and economic traits was determined by soil water availability, and whether it was related to species distribution and congeneric endemic species composition of the same community. We found that LP species tended to have higher SD, VD, WSGbranch, Al: As, SL, ΨTlp and Vdmax than QM species. There was a significant trade-off between hydraulic efficiency and safety across congeneric species. Also, the relationships between hydraulic and economic traits were closer in LP than in QM. These results suggested that relationships between hydraulic and economic traits, hydraulic efficiency and safety played the role in constraining species distribution across regions. Interestingly, some relationships between traits changed (from significant correlation to non-correlation) in common species across two regions (from LP to QM), but not in endemic species. The change of these seven pairs of relationships might be a reason for common species’ wide occurrence in the two Q. wutaishanica forests with different soil water availability. In drought or humid conditions, congeneric species developed different types of adaptation mechanisms. The study helps to understand the environmental adaptive strategies of plant species, and the results improve our understanding of the role of both hydraulic and economic traits during community assembly.

Cuticle thickness of leaves varies >100 times across species, yet its dry mass cost and ecological benefits are poorly understood. It has been repeatedly demonstrated that thicker cuticle is not superior as a water barrier, implying that other functions must be important. Here, we measured the mechanical properties, dry mass and density of isolated cuticle from 13 evergreen woody species of Australian forests. Summed adaxial and abaxial cuticle membrane mass per unit leaf area (CMA) varied from 2.95 to 27.4g m(-2) across species, and accounted for 6.7-24% of lamina dry mass. Density of cuticle varied only from 1.04 to 1.24gcm(-3) ; thus variation in CMA was mostly due to variation in cuticle thickness. Thicker cuticle was more resistant to tearing. Tensile strength and modulus of elasticity of cuticle were much higher than those of leaf laminas, with significant differences between adaxial and abaxial cuticles. While cuticle membranes were thin, they could account for a significant fraction of leaf dry mass due to their high density. The substantial cost of thicker cuticle is probably offset by increased mechanical resistance which might confer longer leaf lifespans among evergreen species.