Leaf Venation Patterns Research Articles

The Effects of Auxin Transport Inhibition on the Formation of Various Leaf and Vein Patterns.

Polar auxin transport (PAT) is a known component controlling leaf complexity and venation patterns in some model plant species. Evidence indicates that PAT generates auxin converge points (CPs) that in turn lead to local leaf formation and internally into major vein formation. However, the role of PAT in more diverse leaf arrangements and vein patterns is largely unknown. We used the pharmacological inhibition of PAT in developing pinnate tomato, trifoliate clover, palmate lupin, and bipinnate carrot leaves and observed dosage-dependent reduction to simple leaves in these eudicots. Leaf venation patterns changed from craspedodromous (clover, carrot), semi-craspedodromous (tomato), and brochidodromous (lupin) to more parallel patterning with PAT inhibition. The visualization of auxin responses in transgenic tomato plants showed that discrete and separate CPs in control plants were replaced by diffuse convergence areas near the margin. These effects indicate that PAT plays a universal role in the formation of different leaf and vein patterns in eudicot species via a mechanism that depends on the generation as well as the separation of auxin CPs. Computer simulations indicate that variations in PAT can alter the number of CPs, corresponding leaf lobe formation, and the position of major leaf veins along the leaf margin in support of experimental results.

Chemotaxonomy compared to morphological and anatomical taxonomy of five Hibiscus species

Hibiscus is a charismatic genus of the Malvaceae family that is noted for its diversity, lacking identifiable characteristics for distinguishing its various species. Therefore, there is an urgent need to develop authentication methods for genus delimitation and species delineation. The present study aims to discern the taxonomic relationships between the well-known, globally familiar, and economically important five Hibiscus species, namely: H. × rosa-sinensis, H. sabdariffa, H. schizopetalus, H. syriacus and H. tiliaceus based on traditional morphological and anatomical characteristics compared to the contemporary chemotaxonomy. In this context, the leaf-based methanolic extracts of the studied species were analyzed by Gas Chromatography-Mass Spectrometer (GC–MS) to estimate their secondary metabolites similarity. In addition, selected qualitative morphological and anatomical traits including leaf venation patterns, epidermal micromorphology, stomata types and trichomes diversity, petiole serial sectioning (outline, adaxial groove features, vasculature traces arrangement), and midrib characteristics of the studied species were investigated. The results of both chemotaxonomy and traditional taxonomy exhibited a remarkable agreement in the delineation of the five studied species. Specifically, the chemotaxonomy-based dendrogram separates the studied species into two main clusters with the H. sabdariffa as an outlier species in a single cluster and the remaining four species as another cluster with variant distances in its similarity indices. Similarly, the traditional morphological and anatomical characteristics revealed distinct traits for H. sabdariffa compared to the remaining four species. The findings of this study highlight the significance of integrating the structural features with phytochemicals profiling as a potential approach that could be harnessed for the delineation of the taxonomically challenging Hibiscus genus.

Multiplexed in situ hybridization reveals distinct lineage identities for major and minor vein initiation during maize leaf development

Leaves of flowering plants are characterized by diverse venation patterns. Patterning begins with the selection of vein-forming procambial initial cells from within the ground meristem of a developing leaf, a process which is considered to be auxin-dependent, and continues until veins are anatomically differentiated with functional xylem and phloem. At present, the mechanisms responsible for leaf venation patterning are primarily characterized in the model eudicot Arabidopsis thaliana which displays a reticulate venation network. However, evidence suggests that vein development may proceed via a different mechanism in monocot leaves where venation patterning is parallel. Here, we employed Molecular Cartography, a multiplexed in situ hybridization technique, to analyze the spatiotemporal localization of a subset of auxin-related genes and candidate regulators of vein patterning in maize leaves. We show how different combinations of auxin influx and efflux transporters are recruited during leaf and vein specification and how major and minor vein ranks develop with distinct identities. The localization of the procambial marker PIN1a and the spatial arrangement of procambial initial cells that give rise to major and minor vein ranks further suggests that vein spacing is prepatterned across the medio-lateral leaf axis prior to accumulation of the PIN1a auxin transporter. In contrast, patterning in the adaxial-abaxial axis occurs progressively, with markers of xylem and phloem gradually becoming polarized as differentiation proceeds. Collectively, our data suggest that both lineage- and position-based mechanisms may underpin vein patterning in maize leaves.

From nature to buildings: a biomimetic approach as an alternative against structures’ humidity issues in Jijel – Algeria

Purpose. This study aims to explore the plants’ potential to adjust to humid climates and understand their acclimation processes to inspire building designs and develop moisture-resistant building materials. It’s based on the top-down biomimetic approach and proposes a method for applying biological processes to architectural concepts, referring to the anatomical diagnoses of moisture-resistant plants. Results. The study revealed that mimicking the hierarchical structuring observed in leaf venation patterns significantly improved the mechanical strength and flexibility of the biomimetic materials. The results indicated that plants had evolved several morphological and physiological adaptations and validated the importance of considering both the cuticle and stomata as essential adaptive factors in developing a biomimetic process. Plant adaptation mechanisms led to a focus on porosity, external textures, hydrophobic additives, and multilayer structures of building materials to produce compositions suitable for humid climates inspired by these principles. Scientific novelty. This research contributes to our understanding of how plants adapt to high humidity levels and underlines the importance of adopting the principles developed by biological systems to survive and cope with changing conditions. Practical value. This study opens insights for more resilient bio-inspired architecture that responds adaptively to humid climatic environments and highlights the significance of creating suitable building materials for different climates and those adapted for climate change.

Fig leaf from the Middle Siwalik sediments of eastern Nepal with implication on biogeography and palaeoclimate

The Siwalik flora is important in understanding the orogeny of the Himalayas and the resulting climate change. Though the fossil records from the eastern Himalayan Siwalik of Nepal are sparse, we report a fossil leaf impression/ compression of Ficus precunea Lakhanpal from the Middle Siwalik (upper Miocene–lower Pliocene) sediments of eastern Nepal. The characteristic leaf venation pattern and morphological details suggest its strong affinity with the extant species of F. semicordata Buch.-Ham. ex Sm. The fossil assemblage indicates the presence of seasonal forests during the depositional period in the region.

Leaf Architecture and Genome Size Variation of Durio zibethinus L. from Jelebu, Negeri Sembilan, Malaysia.

Durio zibethinus L. is known as the "king of fruit" in Malaysia. Meanwhile, Jelebu, Negeri Sembilan has always become the top choice district to visit for durian lover for its Durian Kampung Jelebu, which possessed good quality on par with top D. zibethinus clones such as D197 Musang King and D24. However, there is still lacking in taxonomic data of D. zibethinus especially from Jelebu. This study aimed to analyse the leaf architecture and genome size variations of selected D. zibethinus accessions from Jelebu. Five D. zibethinus accessions from Jelebu were examined. Thirty-seven parameters of gross leaf morphological characteristics and leaf venation pattern were observed and recorded for identification and classification of D. zibethinus accessions from Jelebu. Seven parameters have been recorded which are petiole length, petiole features, leaf size, leaf shape, leaf base shape, lower leaf surface colour and areolation could be used in differentiating between accessions. Results of this study showed the intraspecific variations existed among D. zibethinus accessions from Jelebu with a genome size varying between 1.7433 pg and 1.800 pg. In conclusion, data on leaf architecture and genome size variations from D. zibethinus accessions are beneficial for early plant identification and classification.

Effect of life cycle and venation pattern on the coordination between stomatal and vein densities of herbs.

Life cycle (annual vs perennial) and leaf venation pattern (parallel and reticular) are known to be related to water use strategies in herb species and critical adaptation to certain climatic conditions. However, the effect of these two traits and how they influence the coordination between vein density (vein length per area, VLA) and stomatal density (SD) remains unclear. In this study, we examined the leaves of 53 herb species from a subtropical botanical garden in Guangdong Province, China, including herbs with different life cycles and leaf venation patterns. We assessed 21 leaf water-related functional traits for all species, including leaf area (LA), major and minor VLA, major and minor vein diameter (VD), SD and stomatal length (SL). The results showed no significant differences in mean SD and SL between either functional group (parallel venation vs reticular venation and annual vs perennial). However, parallel vein herbs and perennial herbs displayed a significantly higher mean LA and minor VD, and lower minor VLA compared to reticular vein herbs and annual herbs, respectively. There was a linear correlation between total VLA and SD in perennial and reticular vein herbs, but this kind of correlation was not found in annual and parallel vein herbs. The major VLA and minor VD were significantly affected by the interaction between life cycle and leaf venation pattern. Our findings suggested that VLA, rather than SD, may serve as a more adaptable structure regulated by herbaceous plants to support the coordination between leaf water supply and demand in the context of different life cycles and leaf venation patterns. The results of the present study provide mechanistic understandings of functional advantages of different leaf types, which may involve in species fitness in community assembly and divergent responses to climate changes.

DEFECTIVELY ORGANIZED TRIBUTARIES 5 is not required for leaf venation patterning in Arabidopsis thaliana.

The search for genetic regulators of leaf venation patterning started over 30 years ago, primarily focused on mutant screens in the eudicotyledon Arabidopsis thaliana. Developmental perturbations in either cotyledons or true leaves led to the identification of transcription factors required to elaborate the characteristic reticulated vein network. An ortholog of one of these, the C2H2 zinc finger protein DEFECTIVELY ORGANIZED TRIBUTARIES 5 (AtDOT5), was recently identified through transcriptomics as a candidate regulator of parallel venation in maize (Zea mays) leaves. To elucidate how AtDOT5 regulates vein patterning, we generated three independent loss-of-function mutations by gene editing in Arabidopsis. Surprisingly, none of them exhibited any obvious phenotypic perturbations. To reconcile our findings with earlier reports, we re-evaluated the original Atdot5-1 and Atdot5-2 alleles. By genome sequencing, we show that reported mutations at the Atdot5-1 locus are actually polymorphisms between Landsberg erecta and Columbia ecotypes, and that other mutations present in the background most likely cause the pleiotropic mutant phenotype observed. We further show that a T-DNA insertion in the Atdot5-2 locus has no impact on leaf venation patterns when segregated from other T-DNA insertions present in the original line. We thus conclude that AtDOT5 plays no role in leaf venation patterning in Arabidopsis.

Comparative foliar morphological and palynological studies of Cleomaceae of Assam, India

Abstract. Das B, Roy S, Kalita S, Boro KK, Nath M, Nath N. 2022. Comparative foliar morphological and palynological studies of Cleomaceae of Assam, India. Biodiversitas 23: 2920-2934. The Cleomaceae is a well-known angiospermic family. There is no record of extensive study on the members of the family Cleomaceae in the state of Assam. Though the species Cleome houtteana is found abundantly in the studied area, it was not reported in any of the major floristic works of the region and it was misidentified as Gynandropsis gynandra by many of the earlier workers. So, the present work was carried out to do a detailed comprehensive study on the morphology, foliar macro and micro-morphology (epidermis, stomata, and trichome), leaf venation pattern, along with palynological characters of the four species of Cleomaceae viz. Gynandropsis gynandra, Cleome houtteana, Sieruela rutidosperma, and Arivela viscosa of Assam, India. These species show similarities with each other, but can be well differentiated using the studied characters here. Detailed taxonomic descriptions have been given along with relevant information and color photographs for the correct identification of all four different species.

Leaf architectural analysis of taxonomically ambiguous Hoya lacunosa Blume and Hoya krohniana Kloppenb. & Siar

Abstract. Scott HC, Buot JR IE. 2022. Leaf architectural analysis of taxonomically ambiguous Hoya lacunosa Blume and Hoya krohniana Kloppenb. & Siar. Biodiversitas 23: 2055-2065. The horticulturally important Hoya R.Br. species Hoya lacunosa Blume and Hoya krohniana Kloppenb. & Siar are often mistaken for each other because of their generally similar inflorescence morphology. Based on the hypothesis that leaf venation patterns are genetically fixed, leaf architectural analysis was done to determine the difference between these two taxonomically confusing species. Thirty fully expanded leaves were obtained per species from mature plants of H. lacunosa, H. krohniana and an outgroup, H. pubicorolla. Laminar and venation characters were analyzed using standard leaf architecture protocols. Results show that the main distinction lies in their laminar characters, particularly the base angle and base shape. H. lacunosa samples showed acute to obtuse base angles with cuneate and convex leaf bases, while H. krohniana were found to have obtuse reflex base angles with convex, cordate and rounded leaf bases. Analysis of venation characters shows no considerable difference between the patterns seen in H. lacunosa and the patterns observed in H. krohniana. Further investigation of higher vein orders is recommended. Initial comparison of H. lacunosa pollinaria with the photos of H. krohniana pollinaria from its type description show strikingly similar morphology; for this reason, we also recommend floral morphology comparisons, particularly pollinaria morphology to further establish the similarity and delineation of H. lacunosa and H. krohniana.

Primula tsaiana (Primulaceae), a New Species from Yunnan, China, and a New Synonym of P. wenshanensis

Primula nghialoensis D.W.H. Rankin (Primulaceae) is reduced to the synonym of P. wenshanensis Chen & C.M. Hu. A new species, P. tsaiana G. Hao & Y. Xu, from southeastern Yunnan, China, is described and illustrated. It is similar to P. wenshanensis and P. petelotii, but can be distinguished from them by its distinct rhizome, leaf venation pattern, and shortly lacerated corolla lobes.

Shape-dependent leaf manipulation in the leaf rolling weevil Phymatapoderus pavens (Coleoptera: Attelabidae)

Abstract Plant leaves are utilized by various shelter-building insects. Some insects are constrained in their host plant use by the difficulty in modifying leaves into shelters, while others may cope through different construction methods. Here, we show that the leaf-rolling weevil Phymatapoderus pavens (Coleoptera, Attelabidae) constructs two types of leaf rolⅼ on Boehmeria silvestrii (Urticaceae) according to the shape of the leaf. Female weevils make leaf rolls using the whole leaf when the leaf is small and weakly lobed, whereas they use only one of the lateral lobes when the leaf is large and deeply lobed. Both types were found within a population and each functioned as a site for the growth of offspring. Weevils bite the leaf veins differently when constructing each of these leaf rolls, suggesting that the leaf roll type is determined before the leaf is rolled. Compared with another leaf-rolling weevil species, Apoderus praecellens (Coleoptera, Attelabidae), which makes leaf rolls on similarly lobed leaves of Isodon umbrosus var. hakusanensis (Lamiaceae), P. pavens utilizes a wider range of leaf shapes because these weevils are able to construct leaf rolls on the lateral lobes of the leaves. Differences in leaf-rolling behaviour, leaf venation pattern, and the relative size of weevils and leaves are factors affecting the results.

Leaf venation of living species of Persea (Lauraceae), with taxonomic and nomenclatural notes

With the aim of recognizing and identifying both fertile and sterile specimens of Persea, leaf venation patterns of 54 taxa were studied, 36 of them being described and illustrated for the first time. Analysis of a matrix of 12 leaf venation characters and 31 states distinguishes the taxa and can be used to detect misidentifications. Additionally, lectotypes for the names Laurus cordata, L. lingue (second-step), L. subcordata, Menestrata racemosa, Persea cordata var. microphylla, P. donnell-smithii, P. laevigata, P. lingue, P. nivea and P. rugosa are designated, and the identity of Persea microneura and the status of P. jariensis are clarified.

Morphological diversity and phenetic relationship of wild and cultivated Begonia based on morphology and leaf venation

Abstract. Permata DA, Susandarini R. 2021. Morphological diversity and phenetic relationship of wild and cultivated Begonia based on morphology and leaf venation. Biodiversitas 23: 928-937. Begonia is an ornamental plant with intense cultivation and hybridization practices because of the uniqueness and beauty of its leaves. Begonia with a very large number of species is interesting to study, especially because Indonesia is one of the resource centers of this genus diversity as indicated by the increasing number of new species found every year. This study aimed to explore the morphological diversity of wild and cultivated Begonia and reveal the phenetic relationships of the species and hybrids based on morphology and leaf venation patterns. In this study, we used 19 Begonia samples belonging to five species collected from their natural habitat and 14 species and hybrids obtained from the nurseries. Morphological observations of living specimens and examination on microscopic slides of cleared leaf resulted in 28 characters which were used to determine phenetic relationships using cluster analysis. The high variability of leaf venation patterns described in this study disclosed the micromorphological diversity of Begonia which has not been widely exposed. The results of morphological observations showed high variabilities in leaf color, leaf shape, and petiole color. The results of cluster analysis and principal component analysis indicated that the grouping of species was mainly determined by the existence of trichomes on leaf surfaces and petiole, leaf venation pattern, leaf variegation, and leaf shape. The grouping of species resulting from cluster analysis can be used in the selection of potential parents to produce new Begonia hybrids through crossing experiments.

Developmental regulation of leaf venation patterns: monocot versus eudicots and the role of auxin.

Organisation and patterning of the vascular network in land plants varies in different taxonomic, developmental and environmental contexts. In leaves, the degree of vascular strand connectivity influences both light and CO2 harvesting capabilities as well as hydraulic capacity. As such, developmental mechanisms that regulate leaf venation patterning have a direct impact on physiological performance. Development of the leaf venation network requires the specification of procambial cells within the ground meristem of the primordium and subsequent proliferation and differentiation of the procambial lineage to form vascular strands. An understanding of how diverse venation patterns are manifest therefore requires mechanistic insight into how procambium is dynamically specified in a growing leaf. A role for auxin in this process was identified many years ago, but questions remain. In this review we first provide an overview of the diverse venation patterns that exist in land plants, providing an evolutionary perspective. We then focus on the developmental regulation of leaf venation patterns in angiosperms, comparing patterning in eudicots and monocots, and the role of auxin in each case. Although common themes emerge, we conclude that the developmental mechanisms elucidated in eudicots are unlikely to fully explain how parallel venation patterns in monocot leaves are elaborated.

Leaf venation reveals its potential for the taxonomy of Hyptidendron Harley (Lamiaceae - Hyptidinae) and supports the recognition of a new species, Hyptidendron cerradoense

Leaf venation has not been widely used in taxonomic integrative works, although some potential in delimiting taxa has been reported. Hyptidendron, a neotropical genus with 20 species, seemed to present some variation in leaf venation patterns, which we sought to further investigate. A number of different herbaria were consulted, and herborized leaves were diaphanized for 20 species of Hyptidendron and a set of unidentified material. The taxa were classified according to their venation patterns. Hyptidendron possesses pinnate semicraspedodromous venation with reticulate irregular tertiary, quaternary and quinternary veins. Freely Ending Veinlets show some variation between species but without clear taxonomic importance. Otherwise, perimarginal veins were greatly informative, being present only in the unidentified material. Together with differences from other species of the genus in leaf shape, margins shape, calyx indumentum and petiole size, we hypothesize the unidentified material as a new species: Hyptidendron cerradoense, described here. We provide a full description, illustration, a distribution map, a preliminary conservation assessment and comments on both the taxonomy and ecology of the new species. Our study supports the importance of leaf venation for taxonomic studies, even in smaller genera.

Computation and Optimization of Structural Leaf Venation Patterns for Digital Fabrication

The morphogenetic design process of networking patterns produces anisotropic structural systems that can offer generative solutions for custom design applications. As an example of this type of pattern application, the leaf venation algorithm is introduced that can be customized through parametric inputs and density maps. This method is extended onto mesh surfaces incorporating multiple software applications combining aspects of parametric design, optimization and digital fabrication. The dynamic workflow is presented using a case study project titled “Calyx,” a public artwork completed using the computational tools developed as part of the research. The networking structural pattern of the sculpture yielded to the development of a geometry optimization process that allowed the digital fabrication of planarized structural members. The technical aspects of the design development and post-rationalization process for the construction of leaf venations patterns are discussed.

Boquila trifoliolata mimics leaves of an artificial plastic host plant

ABSTRACT Upon discovery that the Boquila trifoliolata is capable of flexible leaf mimicry, the question of the mechanism behind this ability has been unanswered. Here, we demonstrate that plant vision possibly via plant-specific ocelli is a plausible hypothesis. A simple experiment by placing an artificial vine model above the living plants has shown that these will attempt to mimic the artificial leaves. The experiment has been carried out with multiple plants, and each plant has shown attempts at mimicry. It was observed that mimic leaves showed altered leaf areas, perimeters, lengths, and widths compared to non-mimic leaves. We have calculated four morphometrical features and observed that mimic leaves showed higher aspect ratio and lower rectangularity and form factor compared to non-mimic leaves. In addition, we have observed differences in the leaf venation patterns, with the mimic leaves having less dense vascular networks, thinner vascular strands, and lower numbers of free-ending veinlets.

Leaf venation patterns in Saxifraga L. species (Saxifragaceae) of Indian Western Himalaya and its taxonomic implications

In the present study leaf venation types of 30 Saxifraga L. species, found in Indian Western Himalaya, were studied. Out of these, leaf venation patterns of 20 species were not previously studied. In total, five major types of leaf venations- acrodomous (perfect-basal; perfect-suprabasal; imperfect-suprabasal), camptodromous (eucamptodromous), campylodromous, hyphodromous, and palinactinodromous – were recorded. Section Micranthes show palinactinodromous; section Ciliatae show mainly acrodromous; section Mesogyne show palinactinodromous; and sect. Porphyrion show acrodromous, eucamptodromous and hyphodromous types of venation. Palinactinodromous appear as the ancestral venation type.

Pharmacobotanical characterization of Monteverdia ilicifolia (Mart. ex Reiss.) Biral leaves and its adulterants sold as medicinal tea in Brazil: a contribution to quality control

Leaves of Monteverdia ilicifolia (“espinheira-santa”) are considered a medicinal tea by the Brazilian Sanitary Surveillance Agency (Anvisa), by their anti-dyspeptic, anti-acid and protective of the gastric mucosa properties. Their spiny margins are similar to those of other botanical species, which may lead to misidentifications. The aim of this work was to evaluate the authenticity of 32 samples of herbal drugs commercialized as “espinheira-santa” in the formal trade in Brazil, by macro and microscopic morphological studies of the leaves. The evaluation of the botanical authenticity was based on leaf venation patterns, shape and anatomy of the petiole and midrib region in cross section, vascular system arrangement and epidermal characters. Analysis of these characters compared to literature data suggests that 34% of the samples are M. ilicifolia and the remaining 66% are Sorocea bonplandii, a species with no clinical studies assuring its effective and safe use, representing thus a potential risk to public health.