Outer Leaf Research Articles

Defective homes in Donegal, Ireland: Effect of exposure conditions and concrete quality on pyrrhotite oxidation and internal sulfate attack

Thousands of homes in County Donegal, Ireland, built from concrete blocks, are damaged by extensive cracks and crumbling that occurred a few years after construction. Recently, research has shown that pyrrhotite oxidation triggering internal sulfate attack (ISA) is the cause. In this study, samples from the strip foundations, the rising blocks, the outer and inner leaf of one undamaged reference home and three affected homes are investigated. As these four structural components differ by concrete quality, exposure condition or both, their effect on ISA is investigated. All three damaged homes contained pyrrhotite in the aggregates, while it was absent in the reference home. ISA in the foundations is in an initial state. It has progressed further in the rising blocks and is most advanced in the outer leaf. Whilst carbonation limits the effects of ISA in the inner leaf, further pyrrhotite oxidation will create expansion leading to ongoing deterioration.

Unmasking Spatial Heterogeneity in Phytotoxicology Mechanisms Induced by Carbamazepine by Mass Spectrometry Imaging and Multiomics Analyses.

Previous studies have highlighted the toxicity of pharmaceuticals and personal care products (PPCPs) in plants, yet understanding their spatial distribution within plant tissues and specific toxic effects remains limited. This study investigates the spatial-specific toxic effects of carbamazepine (CBZ), a prevalent PPCP, in plants. Utilizing desorption electrospray ionization mass spectrometry imaging (DESI-MSI), CBZ and its transformation products were observed predominantly at the leaf edges, with 2.3-fold higher concentrations than inner regions, which was confirmed by LC-MS. Transcriptomic and metabolic analyses revealed significant differences in gene expression and metabolite levels between the inner and outer leaf regions, emphasizing the spatial location's role in CBZ response. Notably, photosynthesis-related genes were markedly downregulated, and photosynthetic efficiency was reduced at leaf edges. Additionally, elevated oxidative stress at leaf edges was indicated by higher antioxidant enzyme activity, cell membrane impairment, and increased free fatty acids. Given the increased oxidative stress at the leaf margins, the study suggests using in situ Raman spectroscopy for early detection of CBZ-induced damage by monitoring reactive oxygen species levels. These findings provide crucial insights into the spatial toxicological mechanisms of CBZ in plants, forming a basis for future spatial toxicology research of PPCPs.

Estimating stability and resilience of ageing masonry walls for enhanced infrastructure management and public safety

ABSTRACT Not counting domestic dwellings, it has been estimated that some tens of thousands of older masonry buildings and structures exist nationally and that many of these are potentially at risk of partial (or worse) collapse from falling or dislodged masonry. This has significant implications for building owners, managers, insurers, the local and national economies, and the urban environment. The problem is caused mainly by the slow deterioration of masonry under atmospheric and other environments and by the corrosion of so-called wall-ties, relatively thin pieces of steel that tie the outer leaf of masonry walls to the inner leaf. The problem is likely to be particularly severe for scenarios such as synoptic windstorms and earthquake events as this causes area-wide damage, and potential wide-spread loss of human life – losses that could be prevented by timely intervention. The present paper deals with the research framework and the methodology being employed in a long-term project to develop tools for cost-effective structural masonry assessment and for risk estimation under structural deterioration conditions. Some early findings with potential immediate practical implications are given. Because the effects of deterioration are long-term, the overall project outcomes will take some years to come to fruition. They will be reported in due course.

A Study of Kale Recognition Based on Semantic Segmentation

The kale crop is an important bulk vegetable, and automatic segmentation to recognize kale is fundamental for effective field management. However, complex backgrounds and texture-rich edge details make fine segmentation of kale difficult. To this end, we constructed a kale dataset in a real field scenario and proposed an UperNet semantic segmentation model with a Swin transformer as the backbone network and improved the model according to the growth characteristics of kale. Firstly, a channel attention module (CAM) is introduced into the Swin transformer module to improve the representation ability of the network and enhance the extraction of kale outer leaf and leaf bulb information; secondly, the extraction accuracy of kale target edges is improved in the decoding part by designing an attention refinement module (ARM); lastly, the uneven distribution of classes is solved by modifying the optimizer and loss function to solve the class distribution problem. The experimental results show that the improved model in this paper has excellent performance in feature extraction, and the average intersection and merger ratio (mIOU) of the improved kale segmentation can be up to 91.2%, and the average pixel accuracy (mPA) can be up to 95.2%, which is 2.1 percentage points and 4.7 percentage points higher than the original UperNet model, respectively, and it effectively improves the segmentation recognition of kale.

Upcycling Romaine lettuce outer leaves by infrared blanching and hot air drying.

Romaine lettuce outer leaves, as opposed to the more commonly marketed heart, are typically discarded and present an opportunity for upcycling as dried powders. Duquesne Romaine lettuce was evaluated to quantify and compare quality attributes of fresh outer and heart leaves, dried powders following hot air drying, and dried powders following an infrared (IR) blanching pretreatment before drying. Attributes measured for fresh leaves included moisture, water activity (Aw), color, total soluble phenolics (TSP), and antioxidant capacity (AC). Drying kinetics and time/energy saving through IR blanching were evaluated. Attributes measured for dried powders included moisture, Aw, color, true density, water vapor isotherms, TSP, AC, cadmium (Cd) content, and pesticide residues. TSP, AC, Cd, and pesticide residues were higher, whereas moisture content and Aw were lower in fresh outer versus heart leaves. Hot air drying reduced TSP and AC to 63.6% and 35.2% of fresh values, respectively, whereas IR blanching further reduced TSP and AC to 37.3% and 25.4% in outer leave powders. On the other hand, TSP and AC increased 237% and 151%, respectively, for unblanched heart powders. Higher increase of TSP than AC in heart leaf powder may indicate synthesis of phenolic compounds activated by abiotic stresses such as cutting and high temperatures at the initial drying stage. IR blanching resulted in significant time/energy savings for drying of outer leaves. Microbial loads were substantially reduced during drying, although microbial population on outer leaves were more resistant. Safe to eat outer leaf Romaine lettuce powders can be produced, assuming appropriate agricultural practices.

Differences in Lipid Order and Dynamics in Plasma Membranes Assessed by Nonlinear Optical Microscopy.

When amphiphilic polar dyes were added to the cells, they intercalated predominantly in the outer leaf of the plasma membrane, making them active for second harmonic generation (SHG). The fluorescence of the dye enabled simultaneous 3D imaging of SHG and two-photon excited fluorescence (TPF). Because SHG intensity is sensitive to the alignment of the dyes, which reflects lipid ordering in the plasma membrane, we assessed the difference in lipid ordering by comparing the SHG intensity normalized to the TPF intensity. Together with an enzyme release assay that detects pore formation in the plasma membrane, our SHG assay revealed how polycations affect lipid ordering at low concentrations, where membrane damage has not yet been examined. By scaling the results of the assays with the charge concentration of the two polycations, polyethylenimine (PEI) and poly-l-lysine (PLL), we found that PEI reduced the lipid order more than PLL, and PLL formed more pores than PEI. A comparison of the SHG and TPF images of the wounded cells revealed that one of the lipid dynamics (flip-flop) was significantly enhanced in the bleb membrane. Moreover, the SHG assay indicated that the biocompatible polymer, poly(N-(2-hydroxypropyl)methacrylamide), did not affect the lipid order. Thus, our technique allows the assessment of the plasma membrane structure at the molecular level.

Dimorphopterus blissoides (Hemiptera: Heteroptera: Blissidae): recent spreading of a neonative species in the Pannonian Basin.

Dimorphopterus blissoides (Baerensprung, 1859) (Hemiptera: Heteroptera: Blissidae) is recorded for the first time from Slovakia and Iran. We provide also additional records of D. blissoides from Bulgaria, Croatia, Greece, Hungary and Romania, and review the distribution of the species. The species is currently spreading in the Pannonian Basin, reaching its northern distribution limit in southern Slovakia. We confirm its development on Phragmites australis, with preference to the loose outer leaf sheaths of the galls of Lipara lucens Meigen, 1830 (Diptera: Chloropidae), where the specimens develop during summer as well as hibernate during winter.

Controlled three-dimensional leaf-like NiCoO2@NiCo layered double hydroxide heterostructures for oxygen evolution electrocatalysts in rechargeable Zn–air batteries

Rechargeable zinc-air batteries (ZABs) have garnered attention as a viable choice for large-scale energy storage due to their advantageous characteristics, such as high energy density and cost-effectiveness. Strategies aimed at improving the kinetics of the oxygen evolution reaction (OER) through advanced electrocatalytic materials or structural designs can significantly enhance the efficiency and longevity of ZABs. In this study, we introduce a three-dimensional (3D) leaf-vein system heterojunction architecture. In this structure, NiCoO2 nanowire arrays form the central vein, surrounded by an outer leaf composed of NiCo layered double hydroxide (LDH) nanosheets. All these components are integrated onto a substrate made of Ni foam. Notably, when tested in an alkaline environment, the NiCoO2@NiCo LDH exhibited an overpotential of 272 mV at a current density of 10 mA cm−2, and extended durability evaluations over 12 h underscored its robustness at 99.76 %. The rechargeable ZABs achieved a peak power density of 149 mW cm−2. Furthermore, the NiCoO2@NiCo LDH demonstrated stability by maintaining high round-trip efficiencies throughout more than 680 cycles (equivalent to 340 h) under galvanostatic charge–discharge cycling at 5 mA cm−2. The leaf-vein system heterojunction significantly increased the active sites of the catalysts, facilitating charge transport, improving electronic conductivity, and enhancing overall stability.

Roles of Trees for Abatement of Environmental Pollution: A Review

Planet Earth has become inhospitable for the survival of biological species as it is facing the most serious threat from pollution. Forestation for the abatement of pollution and the betterment of the environment is a successful and widely accepted method among the many ways and means to mitigate environmental contamination. Pollutants are collected, assimilated, and stored by trees. The capacity of trees to capture and hold larger particulates on the epidermal and outer leaf surfaces aids in regulating dust pollution. Additionally, trees contribute to high-quality water by reducing soil erosion locally, which lowers silt in water bodies and traps or filters other water pollutants. In the context of noise pollution, trees can reduce 5-8 dB of noise per 100 feet of the forest by reflecting and absorbing sound energy. Utilizing live, green plants to lessen and/or remove toxins from contaminated soil, water, sediments, and the air is known as phytoremediation. Additionally, different types of genetically engineered trees have been developed through recombinant technologies, which can be utilized to remove heavy metals and toxic substances from contaminated sites. Such genetically modified or transgenic plants could help clean up contaminated sites by taking up pollutants using their roots. This review examines both the conventional and recent developments in using trees for bioremediating contaminated or polluted sites. Thus, by proper planting scheme with suitable species will bring healthy life and color to the cement concrete jungle of large congested cities

Recycling of Hazelnut Husk; from Bio‐waste to Phyto‐Assisted Synthesis of Silver Nanoparticles

AbstractIn the present work, green synthesis is utilized in the synthesis of silver nanoparticles with hazelnut (Corylus Colurna) husk which is the outer leaf part of the hazelnut shell and is considered bio‐waste. According to transmission electron microscopy and x‐ray diffraction analysis, the morphology of the silver nanoparticles synthesized by 0.1 g/mL hazelnut husk extract is found to be spherical with an average diameter of 6.57 nm and possesses ultra‐narrow size distribution. UV‐visible spectrometry reveals the absorbance peak range between 450–475 nm which is in the range of surface plasmon resonance peak of silver nanoparticles with spherical morphology. Antibacterial properties of the synthesized silver nanoparticles were tested on E. coli and significant antimicrobial activity was found with up to 79 % areal inhibition efficiency. The research revealed that the hazelnut husk extract, a reducing agent used in syntheses with different mass concentrations of hazelnut husk extract, also affects the size of the nanoparticles, allowing for the possibility of controlling their size. The antibacterial properties of silver nanoparticles, synthesized in a spherical form of different sizes, correspondingly increased their effect on bacteria which is observed in the inhibition zone. The synthesis of silver nanoparticles, which can be used in many fields for agriculture, cosmetics, and medical purposes, using plant extract and minimal chemicals is crucial because it affects its toxicity. The synthesis of silver nanoparticles with hazelnut husk not only reduces the chemical waste and toxicity, but it is both easily accessible and helps the environment and sustainability by recycling a normally considered bio‐waste by‐product of high‐value‐added crop to a technologically valuable product silver. Moreover, synthesized silver nanoparticles could be an essential part of applications ranging from antibacterial surface treatments to drug delivery systems.

Development and application of Single Primer Enrichment Technology (SPET) SNP assay for population genomics analysis and candidate gene discovery in lettuce.

Single primer enrichment technology (SPET) is a novel high-throughput genotyping method based on short-read sequencing of specific genomic regions harboring polymorphisms. SPET provides an efficient and reproducible method for genotyping target loci, overcoming the limits associated with other reduced representation library sequencing methods that are based on a random sampling of genomic loci. The possibility to sequence regions surrounding a target SNP allows the discovery of thousands of closely linked, novel SNPs. In this work, we report the design and application of the first SPET panel in lettuce, consisting of 41,547 probes spanning the whole genome and designed to target both coding (~96%) and intergenic (~4%) regions. A total of 81,531 SNPs were surveyed in 160 lettuce accessions originating from a total of 10 countries in Europe, America, and Asia and representing 10 horticultural types. Model ancestry population structure clearly separated the cultivated accessions (Lactuca sativa) from accessions of its presumed wild progenitor (L. serriola), revealing a total of six genetic subgroups that reflected a differentiation based on cultivar typology. Phylogenetic relationships and principal component analysis revealed a clustering of butterhead types and a general differentiation between germplasm originating from Western and Eastern Europe. To determine the potentiality of SPET for gene discovery, we performed genome-wide association analysis for main agricultural traits in L. sativa using six models (GLM naive, MLM, MLMM, CMLM, FarmCPU, and BLINK) to compare their strength and power for association detection. Robust associations were detected for seed color on chromosome 7 at 50 Mbp. Colocalization of association signals was found for outer leaf color and leaf anthocyanin content on chromosome 9 at 152 Mbp and on chromosome 5 at 86 Mbp. The association for bolting time was detected with the GLM, BLINK, and FarmCPU models on chromosome 7 at 164 Mbp. Associations were detected in chromosomal regions previously reported to harbor candidate genes for these traits, thus confirming the effectiveness of SPET for GWAS. Our findings illustrated the strength of SPET for discovering thousands of variable sites toward the dissection of the genomic diversity of germplasm collections, thus allowing a better characterization of lettuce collections.

Iron uptake of etioplasts is independent from photosynthesis but applies the reduction-based strategy.

Iron (Fe) is one of themost important cofactors in the photosynthetic apparatus, and its uptake by chloroplasts has also been associated with the operation of the photosynthetic electron transport chain during reduction-based plastidial Fe uptake. Therefore, plastidial Fe uptake was considered not to be operational in the absence of the photosynthetic activity. Nevertheless, Fe is also required for enzymatic functions unrelated to photosynthesis, highlighting the importance of Fe acquisition by non-photosynthetic plastids. Yet, it remains unclear how these plastids acquire Fe in the absence of photosynthetic function. Furthermore, plastids of etiolated tissues should already possess the ability to acquire Fe, since the biosynthesis of thylakoid membrane complexes requires a massive amount of readily available Fe. Thus, we aimed to investigate whether the reduction-based plastidial Fe uptake solely relies on the functioning photosynthetic apparatus. In our combined structure, iron content and transcript amount analysis studies, we used Savoy cabbage plant as a model, which develops natural etiolation in the inner leaves of the heads due to the shading of the outer leaf layers. Foliar and plastidial Fe content of Savoy cabbage leaves decreased towards the inner leaf layers. The leaves of the innermost leaf layers proved to be etiolated, containing etioplasts that lacked the photosynthetic machinery and thus were photosynthetically inactive. However, we discovered that these etioplasts contained, and were able to take up, Fe. Although the relative transcript abundance of genes associated with plastidial Fe uptake and homeostasis decreased towards the inner leaf layers, both ferric chelate reductase FRO7 transcripts and activity were detected in the innermost leaf layer. Additionally, a significant NADP(H) pool and NAD(P)H dehydrogenase activity was detected in the etioplasts of the innermost leaf layer, indicating the presence of the reducing capacity that likely supports the reduction-based Fe uptake of etioplasts. Based on these findings, the reduction-based plastidial Fe acquisition should not be considered exclusively dependent on the photosynthetic functions.

Comprehensive investigation of corrugated fiberboard boxes with edge vents for ambient loading of Chinese cabbage: Part Ⅱ – Quality changes in cellulose paper- and LLDPE film-wrapped Chinese cabbage stored in ventilated corrugated fiberboard boxes

Consumption of fresh produce has increased in recent years, as have the post-harvest losses during produce distribution. This has generated a need for optimum post-harvest treatment to increase the longevity of the produce. In this study, the temperature and relative humidity for the storage test were set as the refrigerated container conditions (ambient loading) and the quality change in Chinese cabbage wrapped with a cellulose paper sheet or linear low-density polyethylene (LLDPE) film in ventilated corrugated fiberboard boxes was evaluated. Weight loss, trimming loss, total soluble solid, pH, firmness, and color were measured every 10 d from 0 to 30 d. The weight loss values of Chinese cabbage wrapped with cellulose paper and LLDPE film at 30 d were approximately 3.7–4.4% and less than 1%, respectively. The trimming loss and firmness of Chinese cabbage wrapped with an LLDPE film were significantly better than those wrapped with a cellulose paper sheet at 30 d. However, the outer leaf surface measured by color meter was more damaged in Chinese cabbage wrapped with the LLDPE film than in those wrapped with the cellulose paper sheet because the wrapping of the former was tighter than that of the latter. In addition, the reduction in the mechanical properties of the boxes with 0%, 2%, and 3% of vent hole area against the horizontal cross section containing Chinese cabbage was measured at 0 and 30 d by performing not only mechanical property tests, such as edge crush test, bursting strength test, and box compression strength test, but also data logging of relative humidity in the headspace of each box. The relative humidity in the headspace of each box was constant at 75 ± 5% after the first increase during 0–24 h. Further, we evaluated the results of the box compression strength test at 30 d, comparing them with the required box compression strengths calculated by the equations provided in the criteria of the Fibre Box Association and American Society for Testing and Materials D4619. Thus, our findings can explain the changes in the quality of Chinese cabbage and the mechanical properties of corrugated fiberboard boxes prepared using two different internal package treatments.

Correlation between Parental Transcriptome and Field Data for the Characterization of Heterosis in Chinese Cabbage.

In Chinese cabbage breeding, hybrids have made a terrific contribution due to heterosis, the superior performance of offspring compared to their inbred parents. Since the development of new, top-performing hybrids requires a large scale of human and material resources, the prediction of hybrid performance is of utmost interest to plant breeders. In our research, leaf transcriptome data from eight parents were used to investigate if they might be employed as markers to predict hybrid performance and heterosis. In Chinese cabbage, heterosis of plant growth weight (PGW) and heterosis of head weight (HW) were more obvious than other traits. The number of differential expression genes (DEGs) between parents was related to the PGW, length of the biggest outer leaf (LOL), leaf head height (LHH), leaf head width (LHW), HW, leaf number of head (LNH) and plant height (PH) of hybrids, and up-regulated DEGs number was also associated with these traits. Euclidean and binary distances of parental gene expression levels were significantly correlated with the PGW, LOL, LHH, LHW, HW and PH of hybrids. Additionally, there was a significant correlation between the parental expression levels of multiple genes involved in the ribosomal metabolic pathway and hybrid observations and heterosis in PGW, with the BrRPL23A gene showing the highest correlation with the MPH of PGW(r = 0.75). Therefore, leaf transcriptome data can preliminarily predict the hybrid performance and select parents in Chinese cabbage.

Profiling of carbonyl compounds in fresh cabbage with chemometric analysis for the development of freshness assessment method

Abstract The aim of this study was to screen the distribution of carbonyl compounds (CCs) in fresh cabbage as a sample model of multi-layered leafy vegetables for discovering the universal freshness marker of fresh produces. The distribution of CCs was observed in the three outer leaf layers of the cabbage. The profile of CCs in each leaf will guide the selection of which leaf is the appropriate part to be used to further discover a freshness marker of cabbage during storage treatment at the postharvest stage. The carbonyl compounds in each leaf were extracted using a mixture of chloroform and methanol (2:1). The extracted CCs from samples were derivatized with dansyl hydrazine. A high-performance liquid chromatography-mass spectrometer with multiplexed multiple reactions monitoring (MRM) was used for the comprehensive detection of carbonyl compounds. More than 400 peaks were observed in the MRM chromatogram from all leaves. The distribution of m/z values that represent CCs were analyzed employing the principle component analysis-discriminant analysis by relating it to the leaf position. The distribution of CC was different for each leaf where the leaves of the second and third layers were similar and significantly different from the leaves of the first layer. The accumulation of trans-2-hexenal was dominant in the first layer; therefore, the utilization of the first layer is not suitable as the part of the sample to discover the freshness marker of multi-layered leafy vegetables.

Yield and nutritional quality of soil-cultivated crisphead lettuce (Lactuca sativa L. var. capitata) and corn salad (Valerianella spp.) harvested at different growing periods.

Crisphead lettuce and corn salad varieties were grown during different growing seasons in the greenhouse or in the field under intensive tillage. They were evaluated for agronomic and nutritional quality to determine the influence of growing period, variety, and in the case of lettuce, leaf position (inner, middle, and outer leaf) on total and marketable yield, color parameters, relative chlorophyll, total sugars, isovaleric acid, total phenolic content (TPC), and multielement composition. Significant differences were found among total yield, color parameters (L*, b*, c*, and hue), and relative chlorophyll for crisphead lettuce, and color parameters (L*, a*, b*, c*, and hue) and relative chlorophyll for corn salad varieties. Relative chlorophyll was strongly correlated with most color parameters. The growing period affected yield, relative chlorophyll, TPC, total sugars, isovaleric acid, and multielement composition for corn salad, and the color parameter a* and relative chlorophyll for crisphead lettuce. The position of lettuce leaves had a significant effect on TPC, total sugars, and multielement composition. In addition, this study confirmed that farmers and consumers should pay attention to nutritional quality when selecting different lettuce and corn salad varieties.

Evaluation of Phytochemical Content and the Antioxidant and Antiproliferative Potentials of Leaf Layers of Cabbage Subjected to Hot Air and Freeze-Drying

Cabbage (Brassica oleracea var. capitata f. alba), a cruciferous vegetable, is one of the most widely consumed vegetables worldwide. However, research on whether there are differences in its contents of phytochemicals and biological activities according to the drying method for each portion of the vegetable remains insufficient. The present study investigated the contents of representative polyphenols and isothiocyanates, the antioxidant capacity, and the antiproliferative effects among six leaf layers of cabbage subjected to hot air and freeze-drying. High-performance liquid chromatography analysis showed that most phenolic and flavonoid bioactive compounds were significantly accumulated in the outer cabbage leaf layer (P1), whereas isothiocyanates were most abundant in the leaf layer close to the core of the head (P5). The contents of isothiocyanates, gallic acid, epicatechin, p-coumaric acid, sinapic acid, and myricetin were significantly higher in the hot air-dried sample than in the freeze-dried sample, whereas the contents of catechin hydrate, chlorogenic acid, 4-hydroxybenzoic acid, and rutin hydrate were significantly higher in the freeze-dried sample. Compared to other leaf layers, P1 exhibited high antiproliferative efficacy against pancreatic, breast, and gastric cancer cells. P1 also showed excellent DPPH·(EC 50–4.208 ± 0.033 and 4.611 ± 0.053 mg/mL for hot air and freeze-dried samples, respectively) and ABTS· (2.422 ± 0.068 and 2.224 ± 0.070 mg/mL for hot air and freeze-dried samples, respectively) radical-scavenging effects. These results indicate that the contents of polyphenols and isothiocyanates in cabbage may vary depending on the leaf layer and the drying method. Our findings provide insight for applying appropriate food drying methods that can be used to produce cabbage leaf-based products with enhanced bioactivity.

Hierachical epicuticular wax coverage on leaves of Deschampsia antarctica as a possible adaptation to severe environmental conditions.

Using cryo scanning electron microscopy, the surface micromorphology of vegetative (leaf blade and ligule) and generative (pedicel and outer glume) organs in Deschampsia antarctica, one of the only two flowering plants native to Antarctica, was examined. Whereas the pedicel and outer glume were wax-free, both leaf sides had a prominent epicuticular wax coverage consisting of two superimposed layers: polygonal rodlets formed by fused irregular platelets (the lower wax layer) and membraneous platelets (the upper wax layer). Although the adaxial (inner) and abaxial (outer) leaf surfaces showed a similar microstructure of the wax coverage, they differed in the thickness ratio between lower and upper wax layer. The ligule bore a very loose wax coverage composed of separate scale-like projections or clusters of them. We suppose that the two-layered wax densely covering both leaf surfaces might contribute to the plant adaptation to severe environmental conditions in Antarctica due to an increase of its resistance against cold temperatures, icing, harmful UV radiation, and dehydration. The presence of the epicuticular wax on the abaxial leaf side and the ligule as well as the hierarchical structure of the wax coverage on both leaf surfaces is described in D. antarctica for the first time.

Production of photocurrent and hydrogen gas from intact plant leaves

Here, we show that it is possible to harvest photocurrent directly from unprocessed plant tissues from terrestrial or aquatic environments in bio-photoelectrochemical cells (BPECs) and use the current to produce molecular H2. The source of electrons is shown to originate from the Photosystem II water-oxidation reaction and utilizes exported mediating molecules, especially NADPH. The photocurrent production is dependent on the concentration of the photosynthetic complexes, as an increase in total chlorophyll and oxygen evolution rates in the leaves lead to increased photocurrent rates. The permeability of the outer leaf surface is another important factor in photocurrent harvesting. Different tissues produce photocurrent densities in the range of ∼1–10 mA/cm2 which is significantly higher than microorganism-based BPECs. The relatively high photocurrent and the simplicity of the plants BPEC may pave the way toward the development of future applicative photosynthetic based energy technologies.

Interspecific Crossing between Lilium hansonii Leichtlin and L. brownii var. colchesteri for the Breeding of New Lily Cultivars

This study aimed to generate interspecific hybrids between two remote lily species, L. hansonii Leichtlin and L. brownii var. colchesteri. Reciprocal crosses were performed by conventional and cut-style pollination methods, but viable seeds were only obtained when L. hansonii was used as the female parent, indicating that unilateral incompatibility exists between the two species. In the case of immature seeds, embryos with 2~3 mm were carefully removed from testa for further in vitro culture, and they grew as normal plants. A total of 343 progenies was obtained from the crosses, and hybridity of the progenies were examined using the L9 marker, simple sequence repeat (SSR) marker, at the seedling stage and 92 were confirmed as F1 hybrids. Ploidy level of 76 F1 hybrid was examined and confirmed as diploid. F1 hybrids exhibited intermediate morphologies of the parent in outer tepal and leaf length, but flower shape and color were similar to those of L. hansonii. On the other hand, F1 hybrid plants showed increased flower spots, flower size, and bud numbers, which could be important signatures of the F1 hybrid. This study reports the first attempt to generate an interspecific hybrid between the two species, and therefore, our results from this study would be very informative for future lily breeding.