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Abstract Background Glehnia littoralis is a medicinal and edible plant species having commercial value and has several hundred years of cultivation history. Polyploid breeding is one of the most important and fastest ways to generate novel varieties. To obtain tetraploids of G. littoralis in vitro, colchicine treatment was given to the seeds and then were screened based on morphology, flow cytometry, and root tip pressing assays. Furthermore, transcriptome analysis was performed to identity the differentially expressed genes associated with phenotypic changes in tetraploid G. littoralis. Results The results showed that 0.05% (w/v) colchicine treatment for 48 h was effective in inducing tetraploids in G. littoralis. The tetraploid G. littoralis (2n = 4x = 44) was superior in leaf area, leaf thickness, petiole diameter, SPAD value (Chl SPAD), stomatal size, epidermal tissues thickness, palisade tissues thickness, and spongy tissues thickness to the diploid ones, while the stomatal density of tetraploids was significantly lower. Transcriptome sequencing revealed, a total of 1336 differentially expressed genes (DEGs) between tetraploids and diploids. Chromosome doubling may lead to DNA content change and gene dosage effect, which directly affects changes in quantitative traits, with changes such as increased chlorophyll content, larger stomata and thicker tissue of leaves. Several up-regulated DEGs were found related to growth and development in tetraploid G. littoralis such as CKI, PPDK, hisD and MDP1. KEGG pathway enrichment analyses showed that most of DEGs were enriched in metabolic pathways. Conclusions This is the first report of the successful induction of tetraploids in G. littoralis. The information presented in this study facilitate breeding programs and molecular breeding of G. littoralis varieties.

Abstract C. sintoc is a plant that has a high essential oil content. Essential oils have many health benefits. Mount Ciremai National Park is an area that has abundant vegetation, especially C. sintoc. The purpose of this study was to predict the volume of oil contained in the leaves of C. sintoc based on its growing location in Mount Ciremai National Park (TNGC), West Java. Sampling was carried out in two stages, namely field samples and laboratory samples. Field samples with a single plot measuring 20 x 20 meters. Extraction of laboratory samples by steam distillation method. Data analysis using ANFIS method to predict the volume of essential oil. The results showed that the volume of essential oil in the leaves was largest on the western slope (1,96 ml), northern slope (2,01 ml), eastern slope (1,55 ml) and southern slope (1,37 ml) while the essential oil yield of extract oil in the leaves is found on the western slope (0,08%), northern slope (0,07 %), eastern slope (0,06 %) and southern slope (0,04), On the western slope (1,82 ml), northern slope (1,73 ml). The ANFIS analysis results showed a prediction accuracy of 90,99% with the highest tree productivity when C. sintoc BL grows at an altitude of 650-700 meters above sea level, tree diameter of 42 cm, height of 12 m, growing on sand-textured land and at a humidity of 75 and at a growing temperature range of 25-270C. The value of essential oil production volume is influenced by each variable such as tree diameter, tree height, soil texture, altitude, temperature and humidity.

Abstract Plant species in the white-sandy forests are subject to unstable soils, high salinity, luminosity, extreme temperatures, and flooding caused by tidal cycles. Protium heptaphyllum, a tree species in the Burseraceae family known for its resin production, occurs in both floodable and non-floodable areas. We investigated differences in the accumulated herbivory indexes in leaves during the leaflet lifespan and correlated these data with leaf morphoanatomical traits in plants from floodable and non-floodable areas. Samples of young and mature leaves were processed using standard plant anatomy techniques. The percentage of leaf area consumed by herbivores and quantitative morphoanatomical data were subjected to MANOVA and ANOVA. Herbivory indexes of young and mature leaves were similar between plants from floodable and non-floodable areas. The morphoanatomical features of young leaves were also similar in plants from both areas. However, mature leaves from individuals in the floodable area exhibited longer leaflets and a higher abundance of wider secretory canals compared to plants from the non-floodable area. We suggest that most leaf consumption by herbivores occurs during the early stages of leaf development when there are fewer chemical defenses, and the leaflets are more tender.

Leaf and root are the most sensitive organs to environment, exploring the relationship between root and leaf functional traits and their responses to environmental factors is helpful to reveal the utilization of resources by plants and their adaption trategies to environment. In order to explore the adaptive strategies of coastal plants, the sandy coastal herbaceous plants in Pingtan Island were taken as the research objects. Three distance gradients were set up from sea and land. Six leaf function traits, leaf thickness, individual leaf area, leaf dry matter content, specific leaf area, leaf tissue density, leaf phosphorus content, and five fine root function traits, root average diameter, root tissue density, specific root length, specific root area, root phosphorus content, were measured to analyze the function traits of leaf and root of coastal plants and their responses to soil factors. The results were as follows: (1) The variation coefficient amplitude of root and leaf function traits in intertidal zone was the smallest, and it was the largest on the gradient 30-60 m away from the high tide line. The individual leaf area, leaf phosphorus content, root average diameter, root tissue density, and root phosphorus content increased with the distance from sea to land; the leaf dry matter content, leaf tissue density, specific root length and specific root area decreased. (2) Plants balanced resource allocation between growth and defense through trait combinations, which showed that there were different degrees of correlation among leaf traits, root traits and root-leaf traits. Among the aboveground and underground corresponding traits, leaf thickness-root average diameter, leaf-root phosphorus content were significantly positively correlated. Specific leaf area with specific root length, specific root area, leaf tissue density-root tissue density had no significant correlation. (3) The interpretation degree of soil factors to the changes of coastal plant functional properties was 52.05%, of which the soil salt content had the greatest impact, followed by soil water content, soil electrical conductivity and soil pH value. In conclusion, in the harsh coastal environment, the soil salt content, soil electrical conductivity, soil water content and soil pH value decrease gradually from sea to land, and the overall environment is low in phosphorus and high in salinity. The plants have shown different survival strategies: the plants closer to the sea adopted the strategy of leaf resource conservation type and root resource acquisition type; the plants farther away from the sea, the strategy of leaf resource acquisition type and root resource conservation type is adopted. The results of this study provide a certain reference value for understanding the response mechanism and adaptability of coastal herbs to environmental gradient changes, which is conducive to the analysis of soil and other environmental characteristics to screen and plant suitable species according to gradient, and promote the restoration and protection of coastal plants.

The leaf is not only the main site of photosynthesis, but also an important organ reflecting plant salt tolerance. Discovery of salt-stress-responding genes in the leaf is of great significance for the molecular improvement of salt tolerance in wheat varieties. In this study, transcriptome sequencing was conducted on the leaves of salt-tolerant wheat germplasm CH7034 seedlings at 0, 1, 6, 24, and 48 h after NaCl treatment. Based on weighted gene correlation network analysis of differentially expressed genes (DEGs) under salt stress, 12 co-expression modules were obtained, of which, 9 modules containing 4029 DEGs were related to the salt stress time-course. These DEGs were submitted to the Wheat Union database, and a total of 904,588 SNPs were retrieved from 114 wheat germplasms, distributed on 21 wheat chromosomes. Using the R language package and GAPIT program, association analysis was performed between 904,588 SNPs and leaf salt injury index of 114 wheat germplasms. The results showed that 30 single nucleotide polymorphisms (SNPs) from 15 DEGs were associated with salt tolerance. Then, nine candidate genes, including four genes (TaBAM, TaPGDH, TaGluTR, and TaAAP) encoding enzymes as well as five genes (TaB12D, TaS40, TaPPR, TaJAZ, and TaWRKY) encoding functional proteins, were identified by converting salt tolerance-related SNPs into Kompetitive Allele-Specifc PCR (KASP) markers for validation. Finally, interaction network prediction was performed on TaBAM and TaAAP, both belonging to the Turquoise module. Our results will contribute to a further understanding of the salt stress response mechanism in plant leaves and provide candidate genes and molecular markers for improving salt-tolerant wheat varieties.

Abstract Malva sylvestris L. (common mallow) is a plant species widely used in phytotherapy and ethnobotanical practices since time immemorial. Characterizing the components of this herb might promote a better comprehension of its biological effects on the human body but also favour the identification of the molecular processes that occur in the plant tissues. Thus, in the present contribution, the scientific knowledge about the metabolomic profile of the common mallow was expanded. In particular, the phytocomplex of leaves and flowers from this botanical species and the extraction capacity of different concentrations of ethanol (i.e., 95%, 70%, 50%, and 0%; v/v in ddH2O) for it were investigated by spectrophotometric and chromatographic approaches. In detail, 95% ethanol extracts showed the worst capacity in isolating total phenols and flavonoids, while all the hydroalcoholic samples revealed a specific ability in purifying the anthocyanins. HPLC–DAD system detected and quantified 20 phenolic secondary metabolites, whose concentration in the several extracts depended on their own chemical nature and the percentage of ethanol used in the preparation. In addition, the stability of the purified phytochemicals after resuspension in pure ddH2O was also proved, considering a potential employment of them in biological/medical studies which include in vitro and in vivo experiments on mammalian models. Here, for the first time, the expressed miRNome in M. sylvestris was also defined by Next Generation Sequencing, revealing the presence of 33 microRNAs (miRNAs), 10 typical for leaves and 2 for flowers. Then, both plant and human putative mRNA targets for the detected miRNAs were predicted by bioinformatics analyses, with the aim to clarify the possible role of these small nucleic acids in the common mallow plant tissues and to try to understand if they could exert a potential cross-kingdom regulatory activity on the human health. Surprisingly, our investigations revealed that 19 miRNAs out of 33 were putatively able to modulate, in the plant cells, the expression of various chromosome scaffold proteins. In parallel, we found, in the human transcriptome, a total of 383 mRNAs involved in 5 fundamental mammalian cellular processes (i.e., apoptosis, senescence, cell-cycle, oxidative stress, and invasiveness) that theoretically could be bound and regulated by M. sylvestris miRNAs. The evidence collected in this work would suggest that the beneficial properties of the use of M. sylvestris, documented by the folk medicine, are probably linked to their content of miRNAs and not only to the action of phytochemicals (e.g., anthocyanins). This would open new perspectives about the possibility to develop gene therapies based on miRNAs isolated from medicinal plants, including M. sylvestris.

Climate change is leading to an increase in the intensity, duration, and frequency of severe droughts, especially in southern and southeastern Europe, thus aggravating water scarcity problems. Water deficit stress harms the growth, physiology, and yield of crops like durum wheat. Hence, studying ancient wheat varieties’ stress responses could help identify genetic traits to enhance crop tolerance to environmental stresses. In this background, this study aimed to investigate the effects of PEG 6000-stimulated drought stress in the ancient wheat variety Saragolla and the modern one Svevo by analyzing various biochemical and molecular parameters that can especially condition the stomatal movement. Our data revealed that drought stress caused a significant increase in the levels of total soluble sugars, ABA, and IAA in both selected cultivars to a greater extent in the Saragolla than in the Svevo. We demonstrated that, under water deficit stress, calcium dynamics as well as the expression of ERF109, MAPK3/6, MYB60, and TaTPC1, involved in the activation of drought-related calcium-sensitive pathways, display significant differences between the two varieties. Therefore, our study provided further evidence regarding the ability of the ancient wheat variety Saragolla to better cope with drought stress compared to the modern variety Svevo.

In order to identify volatile oil synthesis related genes in Illicium verum, transcriptome sequencing and assembly annotation were carried out on the leaves of the superior clone Guijiao 69 and common variety Zhen 01, two varieties with significant difference in volatile oil content. Then GO and KEGG pathways analyses of differentially expressed genes (DEGs) were performed. The results were as follows: (1) A total of 84 182 Unigenes were obtained after transcripts assembly, and 59 161 Unigenes were annotated in NR, NT, Swissprot, KEGG, KOG, GO, and Pfam databases. A total of 30 572 DEGs were obtained after filtering the low abundance genes, and 15 025 up-regulated and 15 547 down-regulated genes were identified in Guijiao 69 compared to the common variety Zhen 01. (2) GO classification results showed that 20 287 DEGs were annotated. In addition, 21 600 DEGs were involved in 133 KEGG pathways. Among them, genes encoding the key enzymes related to volatile oil synthesis such as linalool synthase, myrcene synthase, geranyl geranyl pyrophosphate synthase, cinnamoyl CoA reductase, caffeic acid 3-O-methyltransferase and cinnamyl alcohol dehydrogenase were differentially expressed and enriched in monoterpene biosynthesis pathway, terpene skeleton biosynthesis pathway and phenylpropanoid biosynthesis pathway. (3) Transcription factor analysis showed that the DEGs were distributed in 31 transcription factor families, of which MYB family had the most Unigenes. In this study, transcriptome sequencing was performed to analyze the DEGs superior clones and common varieties of I. verum as well as their related functions and pathways. The candidate genes obtained provide the references for further exploring the synthesis mechanism of characteristic components of volatile oil and molecular breeding of I. verum.

Abstract Background Leaves of tobacco (Nicotiana tabacum L.) are flue-cured to use as a key industrial supply in various parts of the world. The quality of tobacco leaves is dependent on chemical components and their proportions. Generally, the stem attached to tobacco leaf is detached before curing. However, the leaf stem remains green for an extended period of time (as compared to leaf) during flue-curing. Hence, it is expected to affect the quality of tobacco's final product. Results To understand the impact of the green stem of leaf on the metabolome of flue-cured tobacco, we employed a broad targeted metabolomics approach. We selected two tobacco cultivars (Yun87 and K326) and cultivated them in five geographic locations in China. For flue-curing, leaves were harvested without a stem (L) or with an attached stem (SPL). After metabolome analysis, a total of 1027 metabolites were annotated in these samples. A variable number of metabolites were differentially accumulated between both types of leaves (depending on geographic location or cultivar) representing an influence of environment or genotype. Interestingly, only 68 metabolites were differentially accumulated between L and SPL samples irrespective of the cultivar or geographic location. These differentially accumulated metabolites belonged to major groups of primary and secondary metabolites. We have discussed the importance of identified metabolites in terms of carbon, nitrogen, and polyphenolic metabolism. Conclusion The present research is the first comprehensive description of several metabolites in tobacco leaves related to the contribution of leaf stem. The current study opens novel prospects for investigating the potential of such metabolites in improving the quality of flue-cured tobacco.

An open-field 3-year-long microplot experiment was set up with three micropropagated lines (SC Blossom, BFT Indiana, and STM Hajdúsági) of giant reed (Arundo donax L.). Plants were grown on a soil cover of a former sewage settling pond located in Debrecen Lovász-Zug, Hungary. Soil cover of the sewage sediment was moderately contaminated with various toxic elements (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, and Zn). The highest total concentration of examined toxic elements in leaves was found in the BFT Indiana line (∑326 mg/kg), while in the SC Blossom and STM Hajdúsági lines, ∑210 mg/kg and ∑182 mg/kg were measured, respectively. The highest Zn concentration (117 mg/kg) was found in the leaves of in BFT Indiana line and was 67% higher than that in SC Blossom and 95% more than in the STM Hajdúsági line. The BFT Indiana leaves showed typical signs of adaptation to heavy metal stress in the case of numerous micromorphometric characteristics. The extent of leaf mesophylls decreased, and the number of bulliform cells and phytoliths, as well as the sclerenchymatous stock, increased. The size of the vascular bundles was reduced. The size of the stomata decreased while the stomatal density increased. It can be concluded that the BFT Indiana line had the best adaptational response to heavy metal stress.

Recent paleobotanical investigations in Vietnam provide a good opportunity to improve our understanding of the biodiversity and paleoclimatic conditions in the geological past of Southeast Asia. Palms (Arecaceae) are a diverse family of typical thermophilous plants with a relatively low tolerance for freezing. In this study, we describe well-preserved fossil palm leaves from the Oligocene Dong Ho Formation of Hoanh Bo Basin, northern Vietnam. Characters of the fossil leaves, such as a fan-shaped costapalmate lamina, an unarmed petiole, a costa slightly enlarged at the base that then tapers distally into the blade, and well-preserved amphistomatic leaves with cuticles, suggest that they represent a new fossil species, which we herein designate Sabalites colaniae A. Song, T. Su, T. V. Do et Z.K. Zhou sp. nov. Together with other paleontological and palaeoclimatic evidence, we conclude that a warm climate prevailed in northern Vietnam and nearby areas during the Oligocene.

Rice is a major staple food, and, hence, doubling its productivity is critical to sustain future food security. Improving photosynthesis, source–sink relationships and grain-filling mechanisms are promising traits for improvement in grain yield. To understand the source–sink relationship and grain yield, a set of contrasting rice genotypes differing in yield and biomass were studied for physiological, biochemical and gene-expression differences. The physiological and yield component traits of selected rice genotypes were analyzed in 2016 and 2017 under field conditions. This led to the categorization of genotypes as high yielding (HY) and high biomass, viz., Dular, Gontra Bidhan 3, Way Rarem, Patchai Perumal, Sahbhagi Dhan, Indira Barani Dhan-1, MTU1010, and Maudamani; while, low yielding (LY) and low biomass, viz. Anjali, Ghanteswari, Parijat, Khao Daw Tai, RKVY-104, Ghati Kamma Nangarhar, BAM4510 and BAM5850. The HY genotypes in general had relatively better values of yield component traits, higher photosynthetic rate (Pn) and chlorophyll (Chl) content. The study revealed that leaf area per plant and whole plant photosynthesis are the key traits contributing to high biomass production. We selected two good-performing (Sahbhagi Dhan and Maudamani) and two poor-performing (Ghanteswari and Parijat) rice genotypes for a detailed expression analysis of selected genes involved in photosynthesis, sucrose synthesis, transport, and starch synthesis in the leaf and starch metabolism in grain. Some of the HY genotypes had a relatively high level of expression of key photosynthesis genes, such as RbcS, RCA, FBPase, and ZEP over LY genotypes. This study suggests that traits, such as leaf area, photosynthesis and grain number, contribute to high grain yield in rice. These good-performing genotypes can be used as a donor in a breeding program aimed at high yields in rice.

Leaf senescence is an important developmental process for deciduous trees during which part of leaf nitrogen is remobilized to branches, thus being beneficial for nitrogen conservation. However, the associated regulatory mechanism remains largely unknown in deciduous trees. In this study, nitrogen dynamics and transcriptomic activity in senescing leaves were measured during autumnal senescence in hybrid poplar. Both concentrations of leaf total nitrogen (N) and amine compounds were found to decline from the pre-senescence (PRE) to the middle-senescence (MS) stage. Although the total N concentration decreased further from MS to the late-senescence (LS) and leveled off to abscission (ABS) stage, amine compound concentration increased continuously from MS to ABS, suggesting that translocation of amine compounds underperformed production of amine compounds in leaves during this period. L-glutamate, L-glutamine and α-aminoadipic acid were the top three amine compounds accumulated in senescent leaves. RNA-Seq profiling identified thousands of differentially expressed genes (DEGs) with functional association with a metabolic transition towards disassimilation. Many genes encoding amino acid metabolism enzymes and amino acid transporters (AATs) were up-regulated. Comparison of expression trend with leaf N dynamics and phylogenetic analysis identified several PtAATs which exhibited down-regulation from MS to LS stage and putatively limited leaf N remobilization. This study can serve as a primary basis to further elucidate the molecular mechanisms of nitrogen remobilization in poplar senescing leaves.

Accurate plant leaf image segmentation provides an effective basis for automatic leaf area estimation, species identification, and plant disease and pest monitoring. In this paper, based on our previous publicly available leaf dataset, an approach that fuses YOLOv8 and improved DeepLabv3+ is proposed for precise image segmentation of individual leaves. First, the leaf object detection algorithm-based YOLOv8 was introduced to reduce the interference of backgrounds on the second stage leaf segmentation task. Then, an improved DeepLabv3+ leaf segmentation method was proposed to more efficiently capture bar leaves and slender petioles. Densely connected atrous spatial pyramid pooling (DenseASPP) was used to replace the ASPP module, and the strip pooling (SP) strategy was simultaneously inserted, which enabled the backbone network to effectively capture long distance dependencies. The experimental results show that our proposed method, which combines YOLOv8 and the improved DeepLabv3+, achieves a 90.8% mean intersection over the union (mIoU) value for leaf segmentation on our public leaf dataset. When compared with the fully convolutional neural network (FCN), lite-reduced atrous spatial pyramid pooling (LR-ASPP), pyramid scene parsing network (PSPnet), U-Net, DeepLabv3, and DeepLabv3+, the proposed method improves the mIoU of leaves by 8.2, 8.4, 3.7, 4.6, 4.4, and 2.5 percentage points, respectively. Experimental results show that the performance of our method is significantly improved compared with the classical segmentation methods. The proposed method can thus effectively support the development of smart agroforestry.

Polygonatum odoratum (Mill.) Druce possesses widespread medicinal properties; however, the continuous cropping (CC) often leads to a severe consecutive monoculture problem (CMP), ultimately causing a decline in yield and quality. Photosynthesis is the fundamental process for plant growth development. Improving photosynthesis is one of the most promising approaches to increase plant yields. To better understand how P. odoratum leaves undergo photosynthesis in response to CC, this study analyzed the physiochemical indexes and RNA-seq. The physiochemical indexes, such as the content of chlorophyll (chlorophyll a, b, and total chlorophyll), light response curves (LRCs), and photosynthetic parameters (Fv/Fm, Fv/F0, Fm/F0, Piabs, ABS/RC, TRo/RC, ETo/RC, and DIo/RC) were all changed in P. odoratum under the CC system. Furthermore, 13,798 genes that exhibited differential expression genes (DEGs) were identified in the P. odoratum leaves of CC and first cropping (FC) plants. Among them, 7932 unigenes were upregulated, while 5860 unigenes were downregulated. Here, the DEGs encoding proteins associated with photosynthesis and carbon assimilation showed a significant decrease in expression under the CC system, such as the PSII protein complex, PSI protein complex, Cytochorome b6/f complex, the photosynthetic electron transport chain, light-harvesting chlorophyll protein complex, and Calvin cycle, etc., -related gene. This study demonstrates that CC can suppress photosynthesis and carbon mechanism in P. odoratum, pinpointing potential ways to enhance photosynthetic efficiency in the CC of plants.

The orchid genus Brachystele Schltr. (Orchidoideae, Cranichideae, Spiranthinae) comprises 20 species distributed from Mexico to Argentina, with 10 species found in Brazil. Anatomical studies of Orchidoideae Lindl. have been scarce, and the anatomy and histochemistry of Brachystele are still largely unknown. In this study, we conducted a characterization of the vegetative organs of B. guayanensis (Lindl.) Schltr. using standard anatomical and histochemical microtechniques. In this study, we provide the first information about the anatomy and histochemistry of Brachystele. The studied species was observed to display anatomical characters commonly found in the vegetative organs of representatives of the Cranichideae tribe (e.g., uniseriate epidermis; homogeneous mesophyll with 6–11 layers; rhizomes with rings of fibers; vascular bundles in the form of “^” or “v”; fleshy roots with uniseriate velamen, simple trichomes, and spiranthosomes). Others can be interpreted as adaptive strategies conditioned by the environment and their terrestrial life form (e.g., cuticle thickness; amphistomatic leaves; roots with reduced velamen compared to the cortex (18–20 layers); and raphides). In this study, cataphylls, and the presence of spiranthosomes in leaves, including stomatal guard cells, as well as alkaloids in these structures, are anatomically described for the first time in Orchidaceae. The presence of hyphae and pelotons in the stem of B. guayanensis is described for the first time in Cranichideae. Histochemical tests confirmed the presence of lignin, proteins, and alkaloids, the lipidic nature of the cuticle, starch grains stored in spiranthosomes, and the composition of the raphides. Alkaloids were observed in abundance, particularly in the roots, suggesting a potential role in defense against pathogens and herbivores, as well as potential medicinal activities, as seen in phylogenetically related groups to Brachystele.

Populus pruinosa Schrenk has the biological characteristics of heteromorphic leaves and is a pioneer species for wind prevention and sand fixation. The functions of heteromorphic leaves at different developmental stages and canopy heights of P. pruinosa are unclear. To clarify how developmental stages and canopy height affect the functional characteristics of leaves, this study evaluated the morphological anatomical structures and the physiological indicators of leaves at 2, 4, 6, 8, 10, and 12 m. The relationships of functional traits to the developmental stages and canopy heights of leaves were also analyzed. The results showed that blade length (BL), blade width (BW), leaf area (LA), leaf dry weight (LDW), leaf thickness (LT), palisade tissue thickness (PT), net photosynthetic rate (Pn), stomatal conductance (Gs), proline (Pro), and malondialdehyde (MDA) content increased with progressing developmental stages. BL, BW, LA, leaf dry weight, LT, PT, Pn, Gs, Pro, and the contents of MDA, indoleacetic acid, and zeatin riboside had significant positive correlations with canopy heights of leaves and their developmental stages. The morphological structures and physiological characteristics of P. pruinosa leaves showed more evident xeric structural characteristics and higher photosynthetic capacity with increasing canopy height and progressive developmental stages. Resource utilization efficiency and the defense ability against environmental stresses were improved through mutual regulation of each functional trait.

Soybean in relay intercropping is initially exposed to a shade environment, followed by exposure to full sunlight after the harvesting of primary crops, e.g., maize. Therefore, soybean’s ability to acclimate to this changing light environment determines its growth and yield formation. However, the changes in soybean photosynthesis under such light alternations in relay intercropping are poorly understood. This study compared the photosynthetic acclimation of two soybean varieties with contrasting shade tolerance, i.e., Gongxuan1 (shade-tolerant) and C103 (shade-intolerant). The two soybean genotypes were grown in a greenhouse under full sunlight (HL) and 40% full sunlight (LL) conditions. Subsequently, after the fifth compound leaf expanded, half of the LL plants were transferred to a high-sunlight environment (LL-HL). Morphological traits were measured at 0 and 10 days, while chlorophyll content, gas exchange characteristics and chlorophyll fluorescence were assayed at 0, 2, 4, 7 and 10 days after transfer to an HL environment (LL-HL). Shade-intolerant C103 showed photoinhibition 10 days after transfer, and the net photosynthetic rate (Pn) did not completely recover to that under a high light level. On the day of transfer, the shade-intolerant variety, C103, exhibited a decrease in net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (E) in the low-light (LL) and low-light-to-high-light (LL-HL) treatments. Additionally, intercellular CO2 concentration (Ci) increased in low light, suggesting that non-stomatal factors were the primary limitations to photosynthesis in C103 following the transfer. In contrast, the shade-tolerant variety, Gongxuan1, displayed a greater increase in Pn 7 days after transfer, with no difference observed between the HL and LL-HL treatments. Ten days after transfer, the shade-tolerant Gongxuan1 exhibited 24.1%, 10.9% and 20.9% higher biomass, leaf area and stem diameter than the intolerant C103. These findings suggest that Gongxuan1 possesses a higher capacity to adapt to variations in light conditions, making it a potential candidate for variety selection in intercropping systems.

Abstract Background To explore the molecular regulatory mechanisms of early stem and leaf development, proteomic analysis was performed on leaves and stems of F genotype alfalfa, with thin stems and small leaves, and M genotype alfalfa, with thick stems and large leaves. Results Based on fold-change thresholds of > 1.20 or

Abstract Background Exogenous 6-benzyladenine (6-BA) could improve leaf defense system activity. In order to better understand the regulation mechanism of exogenous 6-benzyladenine (6-BA) on waterlogged summer maize, three treatments including control (CK), waterlogging at the third leaf stage for 6 days (V3–6), and application of 100 mg dm− 3 6-BA after waterlogging for 6 days (V3–6-B), were employed using summer maize hybrid DengHai 605 (DH605) as the experimental material. We used a labeling liquid chromatography-based quantitative proteomics approach with tandem mass tags to determine the changes in leaf protein abundance level at the tasseling stage. Results Waterlogging significantly hindered plant growth and decreased the activities of SOD, POD and CAT. In addition, the activity of LOX was significantly increased after waterlogging. As a result, the content of MDA and H2O2 was significantly increased which incurred serious damages on cell membrane and cellular metabolism of summer maize. And, the leaf emergence rate, plant height and grain yield were significantly decreased by waterlogging. However, application of 6-BA effectively mitigated these adverse effects induced by waterlogging. Compared with V3–6, SOD, POD and CAT activity of V3–6-B were increased by 6.9, 12.4, and 18.5%, LOX were decreased by 13.6%. As a consequence, the contents of MDA and H2O2 in V3–6-B were decreased by 22.1 and 17.2%, respectively, compared to that of V3–6. In addition, the leaf emergence rate, plant height and grain yield were significantly increased by application of 6-BA. Based on proteomics profiling, the proteins involved in protein metabolism, ROS scavenging and fatty acid metabolism were significantly regulated by 6-BA, which suggested that application of 6-BA exaggerated the defensive response of summer maize at proteomic level. Conclusions These results demonstrated that 6-BA had contrastive effects on waterlogged summer maize. By regulating key proteins related to ROS scavenging and fatty acid metabolism, 6-BA effectively increased the defense system activity of waterlogged summer maize, then balanced the protein metabolism and improved the plant physiological traits and grain yield.

The bHLH transcription factor SPATULA (SPT) has been identified as a regulator during different stages of Arabidopsis development, including the control of leaf size. However, the mechanism via which it performs this function has not been elucidated. To better understand the role of SPT during leaf development, we used a transcriptomic approach to identify putative target genes. We found putative SPT target genes related to leaf development, and to stomata and trichome formation. Furthermore, genes related to anthocyanin biosynthesis. In this work, we demonstrate that SPT is a negative regulator of stomata number and a positive regulator of trichome number. In addition, SPT is required for sucrose-mediated anthocyanin biosynthesis.

Shade avoidance syndrome (SAS) refers to a set of plant responses that increases light capture in dense stands. This process is crucial for plants in natural and agricultural environments as they compete for resources and avoid suboptimal conditions. Although the molecular, biochemical, and physiological mechanisms underlying the SAS response have been extensively studied, the genetic basis of developmental variation in leaves in regard to leaf area, petiole length, and leaf length (i.e., their allometric relationships) remains unresolved. In this study, with the recombinant inbred line (RIL) population, the developmental traits of leaves of Arabidopsis were investigated under two growth density conditions (high- and low-density plantings). The observed changes were then reconstructed digitally, and their allometric relationships were modelled. Taking the genome-wide association analysis, the SNP genotype and the dynamic phenotype of the leaf from both densities were combined to explore the allometry QTLs. Under different densities, leaf change phenotype was analyzed from two core ecological scenarios: (i) the allometric change of the leaf area with leaf length, and (ii) the change of the leaf length with petiole length. QTLs modulating these two scenarios were characterized as ‘leaf shape QTLs’ and ‘leaf position QTLs’. With functional mapping, results showed a total of 30 and 24 significant SNPs for shapeQTLs and positionQTLs, respectively. By annotation, immune pathway genes, photosensory receptor genes, and phytohormone genes were identified to be involved in the SAS response. Interestingly, genes modulating the immune pathway and salt tolerance, i.e., systemic acquired resistance (SAR) regulatory proteins (MININ-1-related) and salt tolerance homologs (STH), were reported to mediate the SAS response. By dissecting and comparing QTL effects from low- and high-density conditions, our results elucidate the genetic control of leaf formation in the context of the SAS response. The mechanism with leaf development × density interaction can further aid the development of density-tolerant crop varieties for agricultural practices.

We conducted a genome-wide transcriptomic analysis of three drought tolerant and sensitive genotypes of common bean to examine their transcriptional responses to terminal drought stress. We then conducted pairwise comparisons between the root and leaf transcriptomes from the resulting tissue based on combined transcriptomic data from the tolerant and sensitive genotypes. Our transcriptomic data revealed that 491 (6.4%) DEGs (differentially expressed genes) were upregulated in tolerant genotypes, whereas they were downregulated in sensitive genotypes; likewise, 396 (5.1%) DEGs upregulated in sensitive genotypes were downregulated in tolerant genotypes. Several transcription factors, heat shock proteins, and chaperones were identified in the study. Several DEGs in drought DB (data Base) overlapped between genotypes. The GO (gene ontology) terms for biological processes showed upregulation of DEGs in tolerant genotypes for sulfate and drug transmembrane transport when compared to sensitive genotypes. A GO term for cellular components enriched with upregulated DEGs for the apoplast in tolerant genotypes. These results substantiated the temporal pattern of root growth (elongation and initiation of root growth), and ABA-mediated drought response in tolerant genotypes. KEGG (kyoto encyclopedia of genes and genomes) analysis revealed an upregulation of MAPK (mitogen activated protein kinase) signaling pathways and plant hormone signaling pathways in tolerant genotypes. As a result of this study, it will be possible to uncover the molecular mechanisms of drought tolerance in response to terminal drought stress in the field. Further, genome-wide transcriptomic analysis of both tolerant and sensitive genotypes will assist us in identifying potential genes that may contribute to improving drought tolerance in the common bean.

The plant fossils of Alum Bluff, northwestern Florida, provide a unique insight into the rarely preserved Miocene flora of the eastern United States. A century has passed since the introductory treatment on the fossil leaf flora of Alum Bluff. More specimens have accumulated over the past two decades, allowing for an updated evaluation of the megafossil flora following a recent study of the palynoflora. The strata consisting of poorly consolidated sand and siltstones with intervening clay layers, here recognized as the Fort Preston Formation of the Alum Bluff Group, are considered to be of Barstovian age (16.3–13.6 Ma), based on co-occurring mammalian remains. Here we recognize 36 kinds of leaves and 10 kinds of fruits and seeds, giving a minimum estimate of at least one fungus, one fern, one gymnosperm, 38 angiosperms and 7 unknowns. We also report one new species and two new combinations. These taxa augment those already reported based on pollen from the same strata, allowing us to portray the vegetation as elm-hickory-cabbage palm forest occurring near the coastline in a deltaic, pro-deltaic, or intertidal shore face environment. The results of a climate analysis of the Alum Bluff flora, using leaf margin and leaf area, give estimates of 19.0°C mean annual temperature and 116.0 cm mean annual precipitation.

Abstract Background YABBY genes play important roles in the growth and polar establishment of lateral organs such as leaves and floral organs in angiosperms. However, the functions of YABBY homologous genes are largely unknown in soybean. Results In this study, we identified GmFILa encoding a YABBY transcription factor belonging to FIL subfamily. In situ mRNA hybridization analysis indicated that GmFILa had specific expression patterns in leaf as well as in flower bud primordia. Ectopic expression of GmFILa in Arabidopsis thaliana altered the partial abaxialization of the adaxial epidermises of leaves. Besides, GmFILa transgenic plants also exhibited longer flowering period and inhibition of shoot apical meristem (SAM) development compared to the wild type plants. Digital expression data and quantitative real-time polymerase chain reaction (qRT-PCR) analysis demonstrated that the expression of GmFILa was induced by biotic and abiotic stresses and hormone treatments. Transcriptome analysis suggested that overexpressing GmFILa yielded 82 significant differentially expressed genes (DEGs) in Arabidopsis leaves, which can be classified into transcription factors, transporters, and genes involved in growth and development, metabolism, signal transduction, redox reaction and stress response. Conclusions These results not only demonstrate the roles of GmFILa involved in leaf adaxial-abaxial polarity in Arabidopsis, but also help to reveal the molecular regulatory mechanism of GmFILa based on the transcriptomic data.

Abstract Background The floral transition is a complex developmental event, fine-tuned by various environmental and endogenous cues to ensure the success of offspring production. Leaves are key organs in sensing floral inductive signals, such as a change in light regime, and in the production of the mobile florigen. CONSTANS and FLOWERING LOCUS T are major players in leaves in response to photoperiod. Morphological and molecular events during the floral transition have been intensively studied in the shoot apical meristem. To better understand the concomitant processes in leaves, which are less described, we investigated the nuclear changes in fully developed leaves during the time course of the floral transition. Results We highlighted new putative regulatory candidates of flowering in leaves. We observed differential expression profiles of genes related to cellular, hormonal and metabolic actions, but also of genes encoding long non-coding RNAs and new natural antisense transcripts. In addition, we detected a significant increase in ploidy level during the floral transition, indicating endoreduplication. Conclusions Our data indicate that differentiated mature leaves, possess physiological plasticity and undergo extensive nuclear reprogramming during the floral transition. The dynamic events point at functionally related networks of transcription factors and novel regulatory motifs, but also complex hormonal and metabolic changes.

The CO2 assimilation rate, N content, Rubisco activation state, and protein distribution to Rubisco and Rubisco activase in the leaf were analyzed for four soybean genotypes at two growth stages under field conditions. The CO2 assimilation rate was largely constant except for one genotype during the reproductive stage. Rubisco activation state significantly decreased with the increase of N content during this period in three of four genotypes. When standardized by total soluble protein amount, Rubisco activase amount was constant during this period in three genotypes. The results in the present study showed the deactivation of Rubisco with the N accumulation, which can result in the constant rate of CO2 assimilation during the reproductive stage of soybean. The deactivation of Rubisco was attributed to an unknown mechanism other than to the deficiency of Rubisco activase.

Quantitative morpho-anatomical features of leaves of nine Clematis taxa (C. alpina ‘Pamela Jackman’, C. macropetala ‘Maidwell Hall’, C. integrifolia ‘Aljonushka’, C. ispahanica ‘Zvezdograd’, C. fargesii ‘Paul Farges’, C. texensis ‘Princess Diana’, C. tibetana, C. viticella, and C. heracleifolia) were determined with the aim to analyze their adaptation to the environmental conditions. Among investigated clematises, there were plants with hypostomatic (C. viticella, C. fargesii ‘Paul Farges’, C. heracleifolia, C. texensis ‘Princess Diana’, C. macropetala ‘Maidwell Hall’, and C. alpina ‘Pamela Jackman’), and amphistomatic leaves (C. ispahanica ‘Zvezdograd’ and C. tibetana). In C. integrifolia ‘Aljonushka’ leaves were hypostomatic, but few solitary stomata were also present on the adaxial surface. In the leaves of investigated taxa, the palisade coefficient ranged from 27.3% (C. alpina ‘Pamela Jackman’) to 49.9% (C. tibetana). The leaves also differed significantly in size. In particular, leaves of C. integrifolia ‘Aljonushka’ were almost ten times smaller than such of C. heracleifolia. As a result of UPGMA clustering, the plants that can survive in severe windy weather in open rocky areas, Clematis tibetana and C. ispahanica ‘Zvezdograd’, were joined in a separate cluster. The second cluster combined C. alpina ‘Pamela Jackman’ and C. macropetala ‘Maidwell Hall’ – cultivars blooming in the spring, during a period of significant difference in daily temperatures. A relatively small leaf area in plants from these two clusters may indicate an adaptation by reducing the transpiration area and general windage. The third cluster united the rest of investigated taxa, mostly – the mesophytic plants with a relatively large leaf area. However, due to similar morpho-anatomical structure of the leaf, the third cluster also comprised C. integrifolia ‘Aljonushka’ with the smallest leaves.

Abstract Besides their ecological importance, epiphytic species of Orchidaceae play economic and social roles through their commercialization and some are at great risk of extinction. The objectives of this study were to characterize the leaf and root anatomy of fourteen epiphytic Orchidaceae species, which occur in indigenous territory in the Parque Estadual da Serra do Tabuleiro (P.E.S.T.), Santa Catarina, Brazil and to identify adaptive anatomical characteristics related to the epiphytic habit. The species are commercialized by the Guarani and were collected during interviews and guided tours with Guarani in the indigenous territory. The results reveal the species have many morphoanatomical structures that are useful during water shortages resulting from the epiphytic habit. Notable characteristics are related to reserving water (i.e., pseudobulbs and a hypodermis with water-storage cells) and resistance to desiccation in the leaf (i.e., conspicuous cuticle, suprastomatic chamber and extraxylary and pericyclic fibers) and root (i.e., tilosomes and/or exodermal thickening and cortex cells with phi thickenings or sclereids). Descriptions and the identification of adaptive characteristics of epiphytic plant species are useful for conservation and cultivation studies, especially for plants commercially used by the Guarani Indians.

While roots and leaves have evolved independently in lycophytes, ferns and seed plants, there is still confusion regarding the morphological evolution of ferns, especially in whisk ferns, which lack true leaves and roots and instead only exhibit leaf-like appendages and absorptive rhizoids. In this study, analyses of comparative transcriptomics on positively selected genes were performed to provide insights into the adaptive evolution of whisk fern morphologies. Significantly clustered gene families specific to whisk ferns were mainly enriched in Gene Ontology (GO) terms “binding proteins” and “transmembrane transporter activity”, and positive selection was detected in genes involved in transmembrane transporter activities and stress response (e.g., sodium/hydrogen exchanger and heat shock proteins), which could be related to the adaptive evolution of tolerance to epiphytic environments. The analysis of TF/TR gene family sizes indicated that some rapidly evolving gene families (e.g., the GRF and the MADS-MIKC families) related to the development of morphological organs were commonly reduced in whisk ferns and ophioglossoid ferns. Furthermore, the WUS homeobox-containing (WOX) gene family and the knotted1-like homeobox (KNOX) gene family, both associated with root and leaf development, were phylogenetically conserved in whisk ferns and ophioglossoid ferns. In general, our results suggested that adaptive evolution to epiphytic environments might have occurred in whisk ferns. We propose that the simplified and reduced leaf and root system in whisk ferns is the result of reduction from the common ancestor of whisk ferns and ophioglossoid ferns, rather than an independent origin.

This study’s objective was to evaluate the adaptive potential of the leaves of Veronica (V. austriaca, V. incana, and V. prostrata) in the arid conditions of the Kryvyi Rih Botanical Garden NAS of Ukraine (KBG) located in the Right-Bank Steppe Cisdnieper. Leaves have been obtained from the collection of ornamental plants of KBG, where these plants are introduced for ten years. The seasonal dynamics of leaf development have been studied during the growing season of 2018, when the most arid climatic conditions were observed. The leaves of the investigated species were found to be dorsoventral, amphistomatic, with an anomocytic stomatal apparatus and bifacial mesophyll. Changes in the anatomical structures of the leaf blade towards xeromorphism were determined. In particular, in all studied specimens thickening of the cuticle, adaxial and abaxial epidermises (except V. prostrata, where the upper epidermis decreased by 35 %) mesophyll occurred. The number of stomata on the abaxial epidermis in all species decreased (the most notably in V. prostrata). Such increase of xeromorphism in V. austriaca, V. incana, and V. prostrata is an adaptive reaction of plants to the effects of extreme arid weather and climatic conditions of the Kryvorizhzhya, which testifies to the plasticity of investigated species and their high adaptation potential to the climatic conditions of the Right-Bank Steppe Cisdnieper.

Our objective was to investigate the effect of water and nitrogen (N) availability on the carbon isotope composition of leaf blades, canes and ripe berry must (juice) in field grown grapevines. In two consecutive years, the combination of two irrigation treatments [Irrigation (I): 70 % of crop evapotranspiration (ETc) and no irrigation (NI)] and three rates of ammonium nitrate [0 (N0), 60 (N60) and 120 (N120) kg/ha N] were applied to two separate vineyards planted with cv. Xinomavro and cv. Cabernet-Sauvignon respectively in a randomised complete block design. Carbon isotope composition (δ13C) of leaf blades, stem water potential (Ψs), and leaf gas exchange were measured at berry set, bunch closure, veraison and maturity during each growing season. δ13C of bulk berry must at maturity and of dormant canes was also measured. Leaf δ13C and cane δ13C decreased with water supply, but increased with N fertilisation. Must δ13C was lower in the irrigated N0 and N60 vines, whereas irrigation treatments did not differ under the N120 rate. The relative weight of irrigation and fertilisation effect on leaf δ13C varied across samplings: N application accounted for a higher proportion of leaf δ13C variance during the early stages of berry growth, whereas irrigation induced higher variance of leaf δ13C after veraison. The weight of the irrigation effect on cane δ13C was higher from that of fertilisation. Discrimination mechanisms against 13C in grapevine could be mediated by both N fertilisation and irrigation. The well-documented explanation of δ13C variation based on isotopic effects during CO2 diffusion through leaf stomata and carboxylation driven by water conditions may not apply to all cases, since additional discriminating processes against 13C associated with CO2 transfer from the intercellular spaces to the carboxylation sites may be affected by nitrogen supply. The study provides evidence for the first time that carbon isotope composition of leaf blades, canes and berry must is modulated by nitrogen supply. Interpretations of carbon isotope natural abundance in field grown grapevine tissues should therefore consider both water and nitrogen availability.

Our objective was to investigate the effect of water and nitrogen (N) availability on the carbon isotope composition of leaf blades, canes and ripe berry must (juice) in field grown grapevines. In two consecutive years, the combination of two irrigation treatments [Irrigation (I): 70 % of crop evapotranspiration (ETc) and no irrigation (NI)] and three rates of ammonium nitrate [0 (N0), 60 (N60) and 120 (N120) kg/ha N] were applied to two separate vineyards planted with cv. Xinomavro and cv. Cabernet-Sauvignon respectively in a randomised complete block design. Carbon isotope composition (δ13C) of leaf blades, stem water potential (Ψs), and leaf gas exchange were measured at berry set, bunch closure, veraison and maturity during each growing season. δ13C of bulk berry must at maturity and of dormant canes was also measured. Leaf δ13C and cane δ13C decreased with water supply, but increased with N fertilisation. Must δ13C was lower in the irrigated N0 and N60 vines, whereas irrigation treatments did not differ under the N120 rate. The relative weight of irrigation and fertilisation effect on leaf δ13C varied across samplings: N application accounted for a higher proportion of leaf δ13C variance during the early stages of berry growth, whereas irrigation induced higher variance of leaf δ13C after veraison. The weight of the irrigation effect on cane δ13C was higher from that of fertilisation. Discrimination mechanisms against 13C in grapevine could be mediated by both N fertilisation and irrigation. The well-documented explanation of δ13C variation based on isotopic effects during CO2 diffusion through leaf stomata and carboxylation driven by water conditions may not apply to all cases, since additional discriminating processes against 13C associated with CO2 transfer from the intercellular spaces to the carboxylation sites may be affected by nitrogen supply. The study provides evidence for the first time that carbon isotope composition of leaf blades, canes and berry must is modulated by nitrogen supply. Interpretations of carbon isotope natural abundance in field grown grapevine tissues should therefore consider both water and nitrogen availability.

In the context of global climate change, the current strategy of agroeconomics focuses on the introduction of unconventional plant species and the selection of new economically important cultivars adapted to the dramatic weather changes. Cornus officinalis (Cornaceae) has Chinese origin, its reintroduction at the M.M. Gryshko National Botanical Garden of NAS of Ukraine started in 1993. Objective of this research was to investigate the biometric parameters of fruits and leaves of C. officinalis genotypes, C. officinalis × C. mas hybrid ‘Etude’ and genotype from the grafting C. officinalis on C. mas under cultivation in M.M. Gryshko National Botanical Garden of the NAS of Ukraine, to determine the degree of adaptation of C. officinalis to the climatic conditions of Ukraine (in particular, Right-Bank Forest Steppe) and selection of promising genotypes for further breeding work. Material and methods. We used: a) 26-year-old maternal plant obtained from a two-year-old seedling in 1993 received from the nursery “Northwoods Wholesale Nursery” Mollala (Oregon, USA), where this species was grown as an ornamental plant; b) seedlings of the matern plant; c) cultivar ‘Etude’, which is an artificial hybrid from crossing C. officinalis × C. mas; and d) genotype obtained from grafting C. officinalis × C. mas. In our experiment, maternal plant is indicated as G-01, while other plants – as G-02–G-08 genotypes. We determined the biometric parameters of the fruit (length, diameter and weight), endocarp (length, diameter and weight), pedicel (length and thickness), leaf blade (length, width and number of lateral veins) and petiole (length, width and thickness). We examined the dynamics of fruit and endocarp formation during the season (genotypes G-01–G-03 and G-05) and compared the biometric characteristics of the fruit of genotypes G-01–G-05 from crops of two years, 2010 and 2018, which were most favorable in weather-climatic conditions. We have processed quantitative data using variation statistics in the PAST 2.10 software. The differences between the samples were estimated using the Tukey-Kramer test. The degree of variability was determined by the coefficient of variation. To assess the level of variability, we used the classification of Mamaev (1975). Results. We have found that the largest fruits in 2010 were observed in the genotype G-01 and the smallest – in the genotype G-03. The coefficient of variation of the linear parameters of the fruit and endocarp was in the range 5.7–10.1%; the level of variability was very low or low. The variability of fruit weight and endocarp was high, with a range of coefficient of variation of 7.0–28.3%. The amplitude of the linear parameters of the leaf was wide (coefficient of variation of 9.8–31.0%). The cultivar ‘Etude’ differed from other C. officinalis genotypes in size and weight of (M = 1800 mg, max = 2400 mg) and a much wider amplitude of variation in the length (17.9–22.6 vs. 14.3–18.2 mm) of the fruit. The largest leaves were in the genotypes G-08 and G-01, and the smallest – in the genotype G-02. The cultivar ‘Etude’ did not differ so much by the mean leaf morphometric indices and number of veins, but it demonstrated one of the highest width of the leaf blade (51.5 mm). Conclusions. The data obtained are important for the economic use of C. officinalis and the cultivar ‘Etude’ as food and medicinal plant, as well as for breeding in climatic conditions of Ukraine and for analysis of hybridization features in the genus Cornus in general.

ABSTRACT: Verbascum L. is the largest genus of the family Scrophulariceae and includes several species are of medicinal importance. The high morphological diversity among the species of the genus Verbascum causes problems in the delimitation of the species. In this study, morphological, anatomical, palynological and seed properties of Verbascum exuberans were investigated. It is a local endemic restricted to the provinces of Manisa and Izmir in West Anatolia. In the root cross-section, the xylem elements occupy a considerable area. The upper part of the epidermis cells in the stem cross-section is covered a distinct cuticle layer. The main vein of the leaf is shapped as bicollateral bundle. Idioblasts were not observed in the epidermis of the leaves of V. exuberans. Seeds of V. exuberans are dark brown and oblong to prismatic and alveolate. Hilum is short and orbicular. The seed coat ornamentation is reticulate-rugose. Pollen grains usually radially symmetrical, isopolar, prolate, tricolpate. Tectum is reticulate.

The strawberry tree (Arbutus unedo L., Ericaceae family) is an evergreen Mediterranean shrub whose leaves and fruits are used in traditional medicine due to their antioxidant, antimicrobial, antidiabetic, diuretic, and antiproliferative properties. The health benefits are mainly attributed to the presence of phenolic compounds. The aim of this study was to compare the phenolic profiles, total phenolic content (TPC), and radical scavenging activity (RSA) of A. unedo leaves and fruits collected at two locations in Croatia. Phenolic profiles were identified using an ultra-high-performance liquid chromatograph (UHPLC) coupled with a hybrid mass spectrometer (LTQ Orbitrap MS). TPC was determined by Folin–Ciocalteu’s assay, while RSA was investigated using DPPH reagent. A total of 64 phenolics (60 and 42 compounds in leaves and fruits, respectively) were identified. Hyperoside and flavan-3-ols were predominant compounds in leaves, while gallocatechin and catechin were the major compounds found in fruits. To the authors’ knowledge, 16 and 5 phenolics in leaves and fruits, respectively, were reported for the first time. Principal component analysis (PCA) showed that UHPLC-LTQ Orbitrap MS could be used to identify which phenolics were able to discriminate samples regarding plant tissue and geographical origin. TPC in leaves and fruits were in the ranges of 67.07–104.74 and 16.78–25.86 mg gallic acid equivalents (GAE)/g dried weight (dw), respectively. RSA for leaves and fruits were in the ranges of 408.92–430.98 and 74.30–104.04 μmol Trolox equivalents (TE)/g dw, respectively. The number of identified phenolics was lower in fruits compared to leaves. Such a large number of bioactive phenolics identified and the strong antioxidant activity pointed to A. unedo as a promising health-promoting plant and natural food preservative.

Citrus fruit is one of the most important contributors to the ascorbic acid (AsA) intake in humans. Here, we report a comparative analysis of AsA content and transcriptional changes of genes related to its metabolism during development of petals, leaves and fruits of Valencia Late oranges (Citrus sinensis). Petals of close flowers and at anthesis contained the highest concentration of AsA. In fruits, AsA content in the flavedo reached a maximum at color break, whereas the pulp accumulated lower levels and experienced minor fluctuations during development. AsA levels in leaves were similar to those in the flavedo at breaker stage. The transcriptional profiling of AsA biosynthetic, degradation, and recycling genes revealed a complex and specific interplay of the different pathways for each tissue. The D-galacturonic acid pathway appeared to be relevant in petals, whereas in leaves the L-galactose pathway (GGP and GME) also contributed to AsA accumulation. In the flavedo, AsA content was positively correlated with the expression of GGP of the L-galactose pathway and negatively with DHAR1 gene of the recycling pathway. In the pulp, AsA appeared to be mainly controlled by the coordination among the D-galacturonic acid pathway and the MIOX and GalDH genes. Analysis of the promoters of AsA metabolism genes revealed a number of cis-acting elements related to developmental signals, but their functionalities remain to be investigated.

This work was aimed at establishing an effective approach for in vitro propagation of Ajuga lupulina Maxim, a medicinal and ornamental plant mainly found in eastern Xizang, in the western Sichuan region of China. We report an optimum response in the proliferation of axillary shoots from nodal segment explants (10.2 shoots/explant) on MS medium containing 3.0 mg L−1 of 6-benzyladenine (BA). When BA and TDZ individually or in combination with NAA were employed for adventitious shoot regeneration, shoots and embryo-like structures (ELSs) were noted in the callus from leaf explants. The maximum response of 26.4 shoots /explant (81.6%) and 12.0 ELSs/explant were ascertained on MS medium with 4.0 mg L−1 TDZ and 0.1 mg L−1 NAA. The leaf despite browning still demonstrated a high regeneration capacity. TDZ (2.0 mg L−1) and BA (2.0 mg L−1) along with NAA (0.01 mg L−1) were found to perform well for shoot regeneration via callus from shoot tip explants. The best for rooting was MS medium (half-strength) containing indole-3-butyric acid (IBA: 1.5 mg L−1) and (NAA: 0.5 mg L−1) with the maximum number of roots (25.8 per shoot) and the highest rooting frequency (81.71%). The survival of the plantlets in the greenhouse was 78.2% indicative of successful acclimatization. This work is the first report of a consistent, definitive, and unique protocol for A. lupulina regeneration, paving the way for the in vitro preservation of such significant genetic resources and also further allied systems based on such callus-based or embryo-based approaches.

Mitogen activated protein kinase (MAPK) pathways are crucial for plant growth and development. The most commonly identified pathways that AtMKK1 has been connected to are wounding, bacterial pathogen response, cold, drought, salt stress, reactive oxygen species stress, touch, and abscisic acid. There is also evidence that AtMKK1 regulates development. In leaf development, auxin can modulate both cell division and expansion and has a key role in both initiation and elaboration of final morphology of both leaves and vascular networks. Distribution of auxin to different tissues and organs relies on auxin transport systems. In our study, it was found that there was reduced response in atmkk1, the AtMKK1 knockout mutant, to 2,3,5-triiodobenzoic acid, an auxin polar transport inhibitor. Analysis of protein-protein interactions has suggested that AtMKK1 may interact with the downstream AtMPK12, which is a negative regulator of auxin signaling. Our results indicate that AtMKK1 may play a role in leaf development.

Background: Both Panax ginseng Meyer and Panax quinquefolius are obligate shade-loving plants whose natural habitats are broadleaved forests of Eastern Asia and North America. Panax species are easily damaged by photoinhibition when they are exposed to high temperatures or insufficient shade. In this study, a cytohistological study of the leaf structures of two of the most well-known Panax species was performed to better understand the physiological processes that limit photosynthesis. Methods: Leaves of ginseng plants grown in soil and hydroponic culture were sectioned for analysis. Leaf structures of both Panax species were observed using a light microscope, scanning electron microscope, and transmission electron microscope. Results: The mesostructure of both P. ginseng and P. quinquefolius frequently had one layer of noncylindrical palisade cells and three or four layers of spongy parenchymal cells. P. quinquefolius contained a similar number of stomata in the abaxial leaf surface but more tightly appressed enlarged grana stacks than P. ginseng contained. The adaxial surface of the epidermis in P. quinquefolius showed cuticle ridges with a pattern similar to that of P. ginseng. Conclusion: The anatomical leaf structure of both P. ginseng and P. quinquefolius shows that they are typical shade-loving sciophytes. Slight differences in chloroplast structure suggests that the two different species can be authenticated using transmission electron microscopy images, and light-resistant cultivar breeding can be performed via controlling photosynthesis efficiency.

Abstract Background Sunflower is recognized as one of the most important oil plants with strong tolerance to drought in the world. In order to study the response mechanisms of sunflower plants to drought stress, gene expression profiling using high throughput sequencing was performed for seedling leaves and roots (sunflower inbred line R5) after 24 h of drought stress (15% PEG 6000). The transcriptome assembled using sequences of 12 samples was used as a reference. Results 805 and 198 genes were identified that were differentially expressed in leaves and roots, respectively. Another 71 genes were differentially expressed in both organs, in which more genes were up-regulated than down-regulated. In agreement with results obtained for other crops or from previous sunflower studies, we also observed that nine genes may be associated with the response of sunflower to drought. Conclusions The results of this study may provide new information regarding the sunflower drought response, as well as add to the number of known genes associated with drought tolerance.

Abstract Habitats under distinct selective pressures exert adaptative pressures that can lead individuals of the same species to present different life strategies for their survival. The aim of this study was to analyse morphoanatomical and physiological traits for identification of adaptive ecological strategies related to both terrestrial and epiphytic life phases of Billbergia euphemiae. It was verified that B. euphemiae showed lower height, as well smaller length, width and foliar area in epiphytic phase than in terrestrial phase. Concerning to foliar anatomy, the thicknesses of leaf and water-storage parenchyma were higher in terrestrial phase, as densities of stomata and scales on the abaxial surface were higher in epiphytic phase. About the contents of photosynthetic pigments, only chlorophyll a/b ratio showed differences between life phases. In both habits, plants exhibited roots with absorption hair. In epiphytic phase, roots exhibited higher velamen thickness, smaller outer cortex, higher number of inner cortex cell layers and higher number of protoxylem poles. Thus, B. euphemiae individuals in epiphytic exhibited lots of traits related to water retention, once these plants are not into the ground. Besides, the plasticity observed may contribute for survival of this group in habitats submitted to modifications (e.g., climate change and other variations caused by human interference).

Objective — to investigate the anatomical and morphological structure of Ginkgo biloba leaves in the heat conditions of Kyiv. Material and methods. The study was carried out on the territory of Academician O.V. Fomin Botanical Garden and M.M. Gryshko National Botanical Garden of the NAS of Ukraine. It was used light and scanning electron microscopy. Results. The investigated plants in O.V. Fomin Botanical Garden have hipostomatic leaves. Adaxial epidermis is formed by polygonal cells. The epidermal tissue cells are large (773.3 cells per 1 mm2). External periclinal walls are curved. The boundaries between the cells are obscure. The surface relief is colycular. Epicuticular wax is present (represented by piddling wax sticks). Abaxial epidermis is formed by epidermal cells and stoma complex. Epidermal cells are polygonal or isodiametral. External periclinal walls of epidermal cells are curved and have papillas formed by external periclinal walls. Epicuticular wax is well-developed, represented by wax sticks. Stomata are not oriented by their stomatal slits along leaf vein and are located between main fascicles, under the level of main epidermal cells. Number of stomata is low (168.6 per 1 mm2). In M.M. Gryshko National Botanical Garden G. biloba trees are characterized by similar micromorphological structure of leaf plates and almost identical to plants from O.V. Fomin Botanical Garden by their epidermal tissue structure. Differences are related to quantitative indicators (plants from M.M. Gryshko National Botanical Garden have more developed epicuticullar wax on both of epidermises, number of stomata per 1 mm2 — 165.3). Conclusion. Taking into account the existing global climate change in the direction of aridization Gingko biloba is promising for use in park landscaping.

The influence of a water supply on the content of phytochemicals (sugars, organic acids, hydroxycinnamic acids, flavonols, flavanols and anthocyanins) in the bud, leaf and fruit of sweet cherry (Prunus avium L.) was studied in two growing seasons. In addition, the shoot length, yield efficiency and fruit weight were determined. The trees of the cultivar ‘Regina’ on Weiroot 72 or Gisela 5 rootstocks were either irrigated or non-irrigated. Irrigated trees received, in addition to rainfall, an amount of water equal to 100% of evapotranspiration, while non-irrigated trees received only rainwater (40% less). An analysis of phytochemicals was performed using high-performance liquid chromatography combined with electrospray ionization mass spectrometry. Irrigated trees had a higher content of total sugars in leaf and bud, higher content of total organic acids in the fruit, and lower content of total hydroxycinnamic acids, total flavonols and flavanols in the leaf and fruit. Irrigated trees also had higher shoot length, fruit weight and lower yield efficiency. The content of phytochemicals in bud and leaf was not affected by rootstock, but the fruit phytochemical composition, shoot length and yield efficiency were. The content of phytochemicals in the bud and leaf was influenced by the presence or absence of fruits. Our results show that irrigation, rootstock and the presence of fruits had an influence on the composition of phytochemicals in sweet cherry.

The studies on the Posidonia oceanica Delile (P. oceanica) phenolic composition have been focused on the foliar tissues and have often neglected the phenolic compounds in rhizomes or roots alike. With the current improvements in high resolution mass spectrometry (HRMS) analyzers, such as the Orbitrap MS, there is a new opportunity to more deeply study P. oceanica. One of the benefits is the possibility of conducting an exhaustive phenolic monitoring, which is crucial in the search for new stressor-specific biomarkers of coastal deterioration. For this purpose, the different tissues (leaf, rhizome, and root) of P. oceanica seagrass from several marine sampling areas were analyzed through target, suspected, and non-target screenings. This paper brings a fast and tissues-specific extraction, as well as a detection method of phenolic compounds applying for the first time the potential of HRMS (Exactive Orbitrap) in P. oceanica samples. As a result, 42 phenolic compounds were satisfactorily detected, of which, to our knowledge, 24 were not previously reported in P. oceanica, such as naringenin, naringenin chalcone and pinocembrin, among others. Information here reported could be used for the evaluation of new stressor-specific biomarkers of coastal deterioration in the Mediterranean waters. Furthermore, the followed extraction and analytical method could be considered as a reference protocol in other studies on marine seagrasses due to the exhaustive search and satisfactory results.

The plant fossils of Alum Bluff, northwestern Florida, provide a unique insight into the rarely preserved Miocene flora of the eastern United States. A century has passed since the introductory treatment on the fossil leaf flora of Alum Bluff. More specimens have accumulated over the past two decades, allowing for an updated evaluation of the megafossil flora following a recent study of the palynoflora. The strata consisting of poorly consolidated sand and siltstones with intervening clay layers, here recognized as the Fort Preston Formation of the Alum Bluff Group, are considered to be of Barstovian age (16.3–13.6 Ma), based on co-occurring mammalian remains. Here we recognize 36 kinds of leaves and 10 kinds of fruits and seeds, giving a minimum estimate of at least one fungus, one fern, one gymnosperm, 38 angiosperms and 7 unknowns. We also report one new species and two new combinations. These taxa augment those already reported based on pollen from the same strata, allowing us to portray the vegetation as elm-hickory-cabbage palm forest occurring near the coastline in a deltaic, pro-deltaic, or intertidal shore face environment. The results of a climate analysis of the Alum Bluff flora, using leaf margin and leaf area, give estimates of 19.0°C mean annual temperature and 116.0 cm mean annual precipitation. [ABSTRACT FROM AUTHOR]

The guayulins are a family of sesquiterpene compounds that consist of an isoprenoid nucleus substituted either by trans-cinnamic or p-anisic acid, and are present only in the resinous fraction of the rubber plant guayule (Parthenium argentatum, Gray). While the natural role of the guayulins remains enigmatic, they may serve as a defense function against other plants or herbivores by virtue of the accumulation of cinnamic acid. Prior research has suggested seasonal variation in guayulin content, which has been shown to decrease as winter arrives in two different varieties. In the present study, the effect of guayulins has been evaluated in 13 different accessions cultivated under the same conditions during autumn. A general reduction in guayulin content was found in the stems from all varieties between the September and November harvest, which was accompanied by an increase in the resin content. With respect to individual guayulins, while guayulin A was the most prominent member during most of the year, guayulin C had more prominence when temperature started to decrease. In this seasonal period, the production of each member of the guayulin family in the leaves was very balanced.

The effect of grazing on leaf photosynthesis has been extensively studied. However, the influence of grazing on photosynthesis in other green tissues, especially spike, has remained poorly understood. This study investigated the impact of different grazing intensities (light grazing (LG), medium grazing (MG), and heavy grazing (HG)) on leaf and spike photosynthesis parameters and photosynthetic pigments of three grass species (Stipa purpurea, Achnatherum inebrians, and Leymus secalinus) on an alpine steppe in the Qilian Mountains. Grazing promoted leaf photosynthesis rate in S. purpurea and L. secalinus but reduced it in A. inebrians. Conversely, spike photosynthesis rate decreased in S. purpurea and L. secalinus under intense grazing, while there was no significant difference in spike photosynthesis rate in A. inebrians. The leaf and spike net photosynthetic rate (Pn) and transpiration rate (Tr) in S. purpurea were the greatest among the three species, while their organ temperatures were the lowest. On the other hand, grazing stimulated leaf chlorophyll biosynthesis in S. purpurea and L. secalinus but accelerated leaf chlorophyll degradation in A. inebrians. Furthermore, spike chlorophyll biosynthesis was inhibited in the three species under grazing, and only L. secalinus had the ability to recover from the impairment. Grazing had a positive effect on leaf photosynthesis parameters of S. purpurea and L. secalinus but a negative effect on those of A. inebrians. However, spike photosynthesis parameters were negatively influenced by grazing. Among the three species investigated, S. purpurea displayed the greatest ability for leaf and spike photosynthesis to withstand and acclimate to grazing stress. This study suggests that moderate grazing enhanced leaf photosynthetic capacity of S. purpurea and L. secalinus but reduced it in A. inebrians. However, spike photosynthetic capacity of three grass species decreased in response to grazing intensities.

The circadian clock is a molecular timer of metabolism that affects the diurnal pattern of stomatal conductance (gs), amongst other processes, in a broad array of plant species. The function of circadian gs regulation remains unknown and here, we test whether circadian regulation helps to optimize diurnal variations in stomatal conductance. We subjected bean (Phaseolus vulgaris) and cotton (Gossypium hirsutum) canopies to fixed, continuous environmental conditions of photosynthetically active radiation, temperature, and vapour pressure deficit (free-running conditions) over 48 h. We modelled gs variations in free-running conditions to test for two possible optimizations of stomatal behaviour under circadian regulation: (i) that stomata operate to maintain constant marginal water use efficiency; or (ii) that stomata maximize C net gain minus the costs or risks of hydraulic damage. We observed that both optimization models predicted gs poorly under free-running conditions, indicating that circadian regulation does not directly lead to stomatal optimization. We also demonstrate that failure to account for circadian variation in gs could potentially lead to biased parameter estimates during calibrations of stomatal models. More broadly, our results add to the emerging field of plant circadian ecology, where circadian controls may partially explain leaf-level patterns observed in the field.

Accurate predictions of species distribution under current and future climate conditions require modeling efforts based on clear mechanistic relationships between climate variables and plant physiological functions. Vulnerability of leaves to xylem embolism is a key mechanistic trait that might be included in these modeling efforts. Here, we propose a simple set-up to measure leaf vulnerability to embolism on the basis of the optical method using a smartphone, a light source, and a notebook. Our data show that this proposed set-up can adequately quantify the vulnerability to xylem embolism of leaf major veins in Populus nigra and Ostrya carpinifolia, producing values consistent with those obtained in temperate tree species with other methods, allowing virtually any laboratory to quantify species-specific drought tolerance on the basis of a sound mechanistic trait.