BnUC1 Is a Key Regulator of Epidermal Wax Biosynthesis and Lipid Transport in Brassica napus.

The bHLH (basic helix-loop-helix) transcription factor AtCFLAP2 regulates epidermal wax accumulation, but the underlying molecular mechanism remains unknown. We obtained BnUC1mut (BnaA05g18250D homologous to AtCFLAP2) from a Brassica napus mutant with up-curling leaves (Bnuc1) and epidermal wax deficiency via map-based cloning. BnUC1mut contains a point mutation (N200S) in the conserved dimerization domain. Overexpressing BnUC1mut in ZS11 (Zhongshuang11) significantly decreased the leaf epidermal wax content, resulting in up-curled and glossy leaves. In contrast, knocking out BnUC1mut in ZS11-NIL (Zhongshuang11-near-isogenic line) restored the normal leaf phenotype (i.e., flat) and significantly increased the leaf epidermal wax content. The point mutation weakens the ability of BnUC1mut to bind to the promoters of VLCFA (very-long-chain fatty acids) synthesis-related genes, including KCS (ß-ketoacyl coenzyme synthase) and LACS (long-chain acyl CoA synthetase), as well as lipid transport-related genes, including LTP (non-specific lipid transfer protein). The resulting sharp decrease in the transcription of genes affecting VLCFA biosynthesis and lipid transport disrupts the normal accumulation of leaf epidermal wax. Thus, BnUC1 influences epidermal wax formation by regulating the expression of LTP and genes associated with VLCFA biosynthesis. Our findings provide a foundation for future investigations on the mechanism mediating plant epidermal wax accumulation.

Taxonomic relevance of leaf surface micromorphology in Korean Clematis L. (Ranunculaceae).

Clematis, one of the largest genera of the family Ranunculaceae, has a wide array of morphological variation and is considered the most difficult group of taxa in terms of infrageneric discrimination. This study assessed the leaf micromorphological features of 19 Clematis taxa (16 species and three varieties) found in Korea. The leaf surface features were studied under scanning electron microscopy, and the stomatal counting and measurement were carried out under light microscopy. Clematis are hypostomatic, meaning the stomata are only found on the abaxial surface of the leaf. Observed taxa showed near uniformity in the epidermal cell type, structure, and morphology on both surfaces of the leaf. Differences were observed in the presence and absence and/or abundance of trichomes on both the adaxial and abaxial surfaces, the epidermal cell boundary, and the periclinal and anticlinal wall of the cells. Differences were also observed in the number of the epidermal cells connected with the stomata on the abaxial surface, with small differences noted in epidermal cell shapes. The ANOVA showed a significant variation in the stomata density in the studied taxa (P < 0.0001). The cluster analysis based on 13 leaf micromorphological features generated four major clusters. These results indicated similarities in certain key leaf micromorphological features among taxa from the Tubulosae, Clematis, and Virona sections. In the genus Clematis, as with other morphological characteristics, using leaf micromorphological characters alone, which possess limited taxonomic value, proves inadequate for resolving infrageneric relationships. However, incorporating certain features with other morphological characteristics offers a possible alternative means of determining the infrageneric relationships within the genus.

Genome-Wide Association Study of Cuticle and Lipid Droplet Properties of Cucumber (Cucumis sativus L.) Fruit.

The fruit surface is a critical first line of defense against environmental stress. Overlaying the fruit epidermis is the cuticle, comprising a matrix of cutin monomers and waxes that provides protection and mechanical support throughout development. The epidermal layer of the cucumber (Cucumis sativus L.) fruit also contains prominent lipid droplets, which have recently been recognized as dynamic organelles involved in lipid storage and metabolism, stress response, and the accumulation of specialized metabolites. Our objective was to genetically characterize natural variations for traits associated with the cuticle and lipid droplets in cucumber fruit. Phenotypic characterization and genome-wide association studies (GWAS) were performed using a resequenced cucumber core collection accounting for >96% of the allelic diversity present in the U.S. National Plant Germplasm System collection. The collection was grown in the field, and fruit were harvested at 16-20 days post-anthesis, an age when the cuticle thickness and the number and size of lipid droplets have stabilized. Fresh fruit tissue sections were prepared to measure cuticle thickness and lipid droplet size and number. The collection showed extensive variation for the measured traits. GWAS identified several QTLs corresponding with genes previously implicated in cuticle or lipid biosynthesis, including the transcription factor SHINE1/WIN1, as well as suggesting new candidate genes, including a potential lipid-transfer domain containing protein found in association with isolated lipid droplets.

PpyLTP36 and PpyLTP39 are involved in the transmembrane transport of cuticular wax and are associated with the occurrence of pear fruit russeting.

Non-specific lipid-transfer proteins (nsLTPs) are a group of small, cysteine-rich proteins that are involved in the transport of cuticular wax and other lipid compounds. Accumulating evidence suggests that dynamic changes in cuticular waxes are strongly associated with fruit russeting, an undesirable visual quality that negatively affects consumer appeal in pears. Currently, the regulatory role of nsLTPs in cuticular wax deposition and pear fruit skin russeting remains unclear. Here, we characterized the variations of cuticular waxes in non-treated (russeted) and preharvest bagging treated (non-russeted) pear fruits throughout fruit development and confirmed that the contents of cuticular waxes were significantly negatively correlated with the occurrence of pear fruit russeting. Based on RNA-Sequencing (RNA-Seq) and quantitative real-time PCR (qRT-PCR) analyses, two nsLTP genes (PpyLTP36 and PpyLTP39) were identified, which exhibited high expression levels in non-russeted pear fruit skins and were significantly repressed during fruit skin russeting. Subcellular localization analysis demonstrated that PpyLTP36 and PpyLTP39 were localized to the plasma membrane (PM). Further, transient Virus-Induced Gene Silencing (VIGS) analyses of PpyLTP36 and PpyLTP39 in pear fruits significantly reduced cuticular wax deposition. In conclusion, PpyLTP36 and PpyLTP39 are involved in the transmembrane transport of cuticular wax and are associated with pear fruit skin russeting.

Identification of long-chain acyl-CoA synthetase gene family reveals that SlLACS1 is essential for cuticular wax biosynthesis in tomato.

Long-chain acyl-CoA synthetases (LACSs), belonging to the acyl-activating enzyme superfamily, play crucial roles in lipid biosynthesis and fatty acid catabolism. Here, we identified 11 LACS genes in the tomato reference genome, and these genes were clustered into six subfamilies. Gene structure and conserved motif analyses indicated that LACSs from the same subfamily shared conserved gene and protein structures. Expression analysis revealed that SlLACS1 was highly expressed in the outer epidermis of tomato fruits and leaves. Subcellular localization assay results showed that SlLACS1 was located in the endoplasmic reticulum. Compared with wild-type plants, the wax content on leaves and fruits decreased by 22.5-34.2 % in SlLACS1 knockout lines, confirming that SlLACS1 was involved in wax biosynthesis in both leaves and fruits. Water loss, chlorophyll extraction, water-deficit, and toluidine blue assays suggested that cuticle permeability was elevated in SlLACS1 knockout lines, resulting in reduction in both drought stress resistance and fruit shelf-life. Overall, our analysis of the LACSs in tomato, coupled with investigations of SlLACS1 function, yielded a deeper understanding of the evolutionary patterns of LACS members and revealed the involvement of SlLACS1 in wax accumulation contribute to drought resistance and extended fruit shelf-life in tomato.

Transcription factors and plant hormones mediate wax metabolism in response to drought stress.

Plants have, throughout evolution, developed a hydrophobic cuticle to protect them from various stresses in the terrestrial environment. The cuticle layer is mainly composed of cutin and cuticular wax, a mixture of very-long-chain fatty acids and their derivatives. With the progress of transcriptome sequencing and other research methods, the key enzymes, transporters and regulatory factors in wax synthesis and metabolism have been gradually identified, especially the study on the regulation of wax metabolism by transcription factors and others in response to plant stress has become a hot topic. Drought is a major abiotic stress that limits plant growth and crop productivity. Plant epidermal wax prevents non-stomatal water loss and improves water use efficiency to adapt to arid environments. In this study, the ways of wax synthesis, transport, metabolism and regulation at different levels are reviewed. At the same time, the regulation of wax by different transcription factors and plant hormones in response to drought is elaborated, and key research questions and important directions for future solutions are proposed to enhance the potential application of epidermal wax in agriculture and the environment.

Convergent evolution of plant prickles by repeated gene co-option over deep time.

An enduring question in evolutionary biology concerns the degree to which episodes of convergent trait evolution depend on the same genetic programs, particularly over long timescales. In this work, we genetically dissected repeated origins and losses of prickles-sharp epidermal projections-that convergently evolved in numerous plant lineages. Mutations in a cytokinin hormone biosynthetic gene caused at least 16 independent losses of prickles in eggplants and wild relatives in the genus Solanum. Homologs underlie prickle formation across angiosperms that collectively diverged more than 150 million years ago, including rice and roses. By developing new Solanum genetic systems, we leveraged this discovery to eliminate prickles in a wild species and an indigenously foraged berry. Our findings implicate a shared hormone activation genetic program underlying evolutionarily widespread and recurrent instances of plant morphological innovation.

A sharp discovery.

Plant prickles are controlled by genes involved in the final step of cytokinin biosynthesis.

Revisiting plant cuticle biophysics.

The plant cuticle is located at the interface of the plant with the environment, thus acting as a protective barrier against biotic and abiotic external stress factors, and regulating water loss. Additionally, it modulates mechanical stresses derived from internal tissues and also from the environment. Recent advances in the understanding of the hydric, mechanical, thermal, and, to a lower extent, optical and electric properties of the cuticle, as well as their phenomenological connections and relationships are reviewed. An equilibrium based on the interaction among the different biophysical properties is essential to ensure plant growth and development. The notable variability reported in cuticle geometry, surface topography, and microchemistry affects the analysis of some biophysical properties of the cuticle. This review aimed to provide an updated view of the plant cuticle, understood as a modification of the cell wall, in order to establish the state-of-the-art biophysics of the plant cuticle, and to serve as an inspiration for future research in the field.

Morpho-anatomical studies of family lamiaceae species of district Lahore, Punjab: a revision to flora of Pakistan.

BACKGROUND: This study was aimed to determine the taxonomic position and delimitation of fifteen Lamiaceae taxa using leaf epidermal morpho-anatomical features in Lahore. A main objective of the study was also the revision and upgradation of Lamiaceae taxa in the flora of Pakistan, as no details of studied species are found in the flora of Pakistan. METHODS: The examination of significant anatomical parameters, such as epidermal cell shape and size, stomatal types, guard and subsidiary cells shape and size, stomatal cavity size, trichome size and shape, oil droplets, crystals, and secretory cavity characteristics were studied using light microscopic (LM) and scanning electron microscopic (SEM) techniques. Among all the studied Lamiaceae species, these anatomical features varied significantly. Principal component analysis and correlation were done to distinguish the species' similarities. RESULTS: Most species had pentagonal and hexagonal epidermal cells with straight anticlinal wall thickness. On the adaxial surface, paracytic stomata were found in Ocimum basilicum L. and Rosmarinus officinalis L. Diacytic stomata was observed in Ajuga reptans L. and anisocytic stomata in Galeopsis tetrahit L. In the abaxial surface, trichomes were present in five species, i.e., Mentha suaveolens Ehrh. A. reptans, Thymus vulgaris L., M. haplocalyx, and Salvia splendens Ewat. In S. splendens, peltate and glandular trichomes were seen whereas, in other species, trichomes were long, unbranched glandular and had tapering ends. In adaxial side trichomes were present only in M. suaveolens, A. reptans, S. bazyntina, O. basciculum, S. splendens, S. officinalis, S. rosemarinus. In other species, trichomes were absent on the adaxial surface. In abaxial view, M. suaveolens had the largest length of trichomes, and O. basciculum had the smallest. S. splendens L. had the largest trichome width, while T. vulgaris had the smallest. CONCLUSION: Hence, according to these findings, morpho-anatomical traits are useful for identifying Lamiaceae taxa. Also, there is a need of upgradation and addition of studied taxa in flora of Pakistan comprehensively.

Amphistomy: stomata patterning inferred from 13C content and leaf-side-specific deposition of epicuticular wax.

BACKGROUND AND AIMS: The benefits and costs of amphistomy (AS) vs. hypostomy (HS) are not fully understood. Here, we quantify benefits of access of CO2 through stomata on the upper (adaxial) leaf surface, using 13C abundance in the adaxial and abaxial epicuticular wax. Additionally, a relationship between the distribution of stomata and epicuticular wax on the opposite leaf sides is studied. METHODS: We suggest that the 13C content of long-chain aliphatic compounds of cuticular wax records the leaf internal CO2 concentration in chloroplasts adjacent to the adaxial and abaxial epidermes. This unique property stems from: (1) wax synthesis being located exclusively in epidermal cells; and (2) ongoing wax renewal over the whole leaf lifespan. Compound-specific and bulk wax 13C abundance (δ) was related to amphistomy level (ASL; as a fraction of adaxial in all stomata) of four AS and five HS species grown under various levels of irradiance. The isotopic polarity of epicuticular wax, i.e. the difference in abaxial and adaxial δ (δab - δad), was used to calculate the leaf dorsiventral CO2 gradient. Leaf-side-specific epicuticular wax deposition (amphiwaxy level) was estimated and related to ASL. KEY RESULTS: In HS species, the CO2 concentration in the adaxial epidermis was lower than in the abaxial one, independently of light conditions. In AS leaves grown in high-light and low-light conditions, the isotopic polarity and CO2 gradient varied in parallel with ASL. The AS leaves grown in high-light conditions increased ASL compared with low light, and δab - δad approached near-zero values. Changes in ASL occurred concomitantly with changes in amphiwaxy level. CONCLUSIONS: Leaf wax isotopic polarity is a newly identified leaf trait, distinguishing between hypo- and amphistomatous species and indicating that increased ASL in sun-exposed AS leaves reduces the CO2 gradient across the leaf mesophyll. Stomata and epicuticular wax deposition follow similar leaf-side patterning.

Research progress on the mechanisms of fruit glossiness in cucumber.

Cucumber (Cucumis sativus L.) is an important horticultural crop in China. Consumer requirements for aesthetically pleasing appearances of horticultural crops are gradually increasing, and cucumbers having a good visual appearance, as well as flavor, are important for breeding and industry development. The gloss of cucumber fruit epidermis is an important component of its appeal, and the wax layer on the fruit surface plays important roles in plant growth and forms a powerful barrier against external biotic and abiotic stresses. The wax of the cucumber epidermis is mainly composed of alkanes, and the luster of cucumber fruit is mainly determined by the alkane and silicon contents of the epidermis. Several genes, transcription factors, and transporters affect the synthesis of ultra-long-chain fatty acids and change the silicon content, further altering the gloss of the epidermis. However, the specific regulatory mechanisms are not clear. Here, progress in research on the luster of cucumber fruit epidermis from physiological, biochemical, and molecular regulatory perspectives are reviewed. Additionally, future research avenues in the field are discussed.

Wheat MIXTA-like Transcriptional Activators Positively Regulate Cuticular Wax Accumulation.

MIXTA-like transcription factors AtMYB16 and AtMYB106 play important roles in the regulation of cuticular wax accumulation in dicot model plant Arabidopsis thaliana, but there are very few studies on the MIXTA-like transcription factors in monocot plants. Herein, wheat MIXTA-like transcription factors TaMIXTA1 and TaMIXTA2 were characterized as positive regulators of cuticular wax accumulation. The virus-induced gene silencing experiments showed that knock-down of wheat TaMIXTA1 and TaMIXTA2 expressions resulted in the decreased accumulation of leaf cuticular wax, increased leaf water loss rate, and potentiated chlorophyll leaching. Furthermore, three wheat orthologous genes of ECERIFERUM 5 (TaCER5-1A, 1B, and 1D) and their function in cuticular wax deposition were reported. The silencing of TaCER5 by BSMV-VIGS led to reduced loads of leaf cuticular wax and enhanced rates of leaf water loss and chlorophyll leaching, indicating the essential role of the TaCER5 gene in the deposition of wheat cuticular wax. In addition, we demonstrated that TaMIXTA1 and TaMIXTA2 function as transcriptional activators and could directly stimulate the transcription of wax biosynthesis gene TaKCS1 and wax deposition gene TaCER5. The above results strongly support that wheat MIXTA-Like transcriptional activators TaMIXTA1 and TaMIXTA2 positively regulate cuticular wax accumulation via activating TaKCS1 and TaCER5 gene transcription.

Regulation of stomatal development by epidermal, subepidermal and long-distance signals.

Plant leaves consist of three layers, including epidermis, mesophyll and vascular tissues. Their development is meticulously orchestrated. Stomata are the specified structures on the epidermis for uptake of carbon dioxide (CO2) while release of water vapour and oxygen (O2), and thus play essential roles in regulation of plant photosynthesis and water use efficiency. To function efficiently, stomatal formation must coordinate with the development of other epidermal cell types, such as pavement cell and trichome, and tissues of other layers, such as mesophyll and leaf vein. This review summarizes the regulation of stomatal development in three dimensions (3D). In the epidermis, specific stomatal transcription factors determine cell fate transitions and also activate a ligand-receptor- MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) signaling for ensuring proper stomatal density and patterning. This forms the core regulation network of stomatal development, which integrates various environmental cues and phytohormone signals to modulate stomatal production. Under the epidermis, mesophyll, endodermis of hypocotyl and inflorescence stem, and veins in grasses secrete mobile signals to influence stomatal formation in the epidermis. In addition, long-distance signals which may include phytohormones, RNAs, peptides and proteins originated from other plant organs modulate stomatal development, enabling plants to systematically adapt to the ever changing environment.

Micromorphological and Chemical Characterization of Drimys winteri Leaf Surfaces: The Secondary Alcohols Forming Epicuticular Wax Crystals Are Accompanied by Alkanediol, Alkanetriol and Ketol Derivatives.

The cuticle is a hydrophobic coating of most aerial plant surfaces crucial for limiting non-stomatal water loss. Plant cuticles consist of the lipid polyester cutin and associated waxes with compositions varying widely between plant species and organs. Here, we aimed to provide a comparative analysis of the dark-glossy adaxial and pale-glaucous abaxial sides of Drimys winteri (Winteraceae) leaves. Scanning electron microscopy showed nanotubular wax crystals lining the entire abaxial side of the leaf (including stomatal pores), while the adaxial side had patches of mixed platelet/tubule crystals and smooth areas between them. Consecutive treatments for wax removal and cutin depolymerization revealed that the waxes were deposited on a cutin network with micron-scale cavities across the entire abaxial surface including the stomata pores, and on a microscopically smooth cutin surface on the adaxial side of the leaf. Gas chromatography coupled to mass spectrometry and flame ionization detection showed that the wax mixtures on both sides of the leaf were complex mixtures of very-long-chain compounds dominated by the secondary alcohol nonacosan-10-ol and alkanediols with one hydroxyl on C-10. It is therefore very likely that the characteristic tubular wax crystals of both leaf sides are formed by these alcohols and diols. Further secondary alcohols and alkanediols, as well as ketols and alkanetriols with one functional group on C-10, were identified based on mass spectral fragmentation patterns. The similarities between all these mid-chain-functionalized compounds suggest that they are derived from nonacosan-10-ol via regio-specific hydroxylation reactions, likely catalyzed by three P450-dependent monooxygenases with different regio-specificities.

Sepal shape variability is robust to cell size heterogeneity in Arabidopsis.

How organisms produce organs with robust shapes and sizes is still an open question. In recent years, the Arabidopsis sepal has been used as a model system to study this question because of its highly reproducible shape and size. One interesting aspect of the sepal is that its epidermis contains cells of very different sizes. Previous reports have qualitatively shown that sepals with more or less giant cells exhibit comparable final size and shape. Here, we investigate this question using quantitative approaches. We find that a mixed population of cell size modestly contribute to the normal width of the sepal but is not essential for its shape robustness. Furthermore, in a mutant with increased cell and organ growth variability, the change in final sepal shape caused by giant cells is exaggerated but the shape robustness is not affected. This formally demonstrates that sepal shape variability is robust to cell size heterogeneity.

Lamiales epidermal dynamics: Unveiling antimicrobial resilience in a structural symphony.

This research on Lamiales epidermal anatomy not only provides in-depth understanding of their structural traits but also highlights the significance of uncovering the inherent antimicrobial resilience embedded within these plants. Such insights hold promise for advancing natural product-based approaches in medicine, potentially contributing to the development of novel antimicrobial agents inspired by Lamiales unique biological defense mechanisms. Scanning microscopic tools were utilized to conduct foliar epidermal anatomy of nine species that belong to seven genera and four families within the Lamiales order, Plantaginaceae, Scrophulariaceae, Verbenaceae, and Lamiaceae. This approach aimed to gather both qualitative and quantitative data, facilitating the assessment of taxonomic microanatomical significance. The shape of epidermal cells and their anticlinal walls; number of epidermal cells, stomata, and trichomes; type of stomata and trichomes; length and width of epidermal cells, trichomes, stomatal pore, guard cells, and subsidiary cells; and stomatal index were determined statistically. Most of the species examined were amphistomatous and showed extensive array of trichomes diversity. The exploration of Lamiales epidermal micromorphology and their antimicrobial potential were significant for their implications in multidisciplinary fields. The pharmacological research to utilize sustainable agricultural practices prompts avenues to strengths of Lamiales order for the development of novel antimicrobial solutions and ecological benefits. RESEARCH HIGHLIGHTS: Diverse trichome morphometry reveals a wide array of trichome structures across Lamiales species. Epidermal microscopic architecture variability of epidermal cell shapes and sizes signifies the interspecies variability. Secondary metabolite localization within microanatomical structures elucidates potential hotspots for antimicrobial compound production.

The cuticular wax composition and crystal coverage of leaves and petals differ in a consistent manner between plant species.

Both leaves and petals are covered in a cuticle, which itself contains and is covered by cuticular waxes. The waxes perform various roles in plants' lives, and the cuticular composition of leaves has received much attention. To date, the cuticular composition of petals has been largely ignored. Being the outermost boundary between the plant and the environment, the cuticle is the first point of contact between a flower and a pollinator, yet we know little about how plant-pollinator interactions shape its chemical composition. Here, we investigate the general structure and composition of floral cuticular waxes by analysing the cuticular composition of leaves and petals of 49 plant species, representing 19 orders and 27 families. We show that the flowers of plants from across the phylogenetic range are nearly devoid of wax crystals and that the total wax load of leaves in 90% of the species is higher than that of petals. The proportion of alkanes is higher, and the chain lengths of the aliphatic compounds are shorter in petals than in leaves. We argue these differences are a result of adaptation to the different roles leaves and petals play in plant biology.

Taxonomic implications of normal and abnormal stomatal complexes in Indigofera L. (Indigofereae, Faboideae, Fabaceae).

This study is the first to report the foliar and stem epidermal micro-morphology of 13 taxa of Indigofera L. (Fabaceae) using light (LM) and scanning electron microscopy (SEM). The micro-morphological characteristics studied here are related to the epidermal cell shape, size, frequency, anticlinal wall pattern, and stomatal complex types, size, position, frequency, and index. The study revealed 19 major normal stomatal types with eight subtypes and seven major abnormal stomatal types with 13 subtypes. The stomatal index was lower on the abaxial leaf surface than on the adaxial surface. Notably, the adaxial surface of I. hochstetteri had the highest stomatal index (27.46%), while the abaxial surface of I. oblongifolia had the lowest (9.95%). The adaxial surface of I. hochstetteri also displayed the highest average stomatal frequency (38.67), while the adaxial surface of I. spinosa had the lowest average frequency (9.37). SEM analysis revealed that most leaves had slightly sunken to sunken stomata, while stem stomata were positioned at the same level as epidermal cells in most taxa. Indigofera's foliar and stem epidermal anatomy recommends their application as baseline data coupled with other taxonomic data for the delimitation and differentiation of closely related taxa in the genus. The study provides a comprehensive description, illustrations, images, and micrographs of the stomatal types, as well as a taxonomic key for distinguishing the studied taxa of Indigofera.

Anatomical features of ecological importance and taxonomic value revealed by scanning electron microscopy and light microscopy in Camonea umbellata (L.) A.R. Simões & Staples (Convolvulaceae).

This article describes detailed and novel data on the anatomy and histochemistry of leaves, stems, and roots of Camonea umbellata (L.) A.R.Simões & Staples in different environments for the identification of characters with taxonomical value and of ecological importance, with provision of light and scanning electron microscopy images. To analyze the characters, we collected samples of the vegetative organs of three individuals in each of three populations, which were in a grazing area, an urban environment, and a biological reserve. The main diagnostic anatomical markers for the identification of C. umbellata include amphistomatic leaves, tetracytic and brachyparatetracytic stomata, peltate trichomes, long simple trichomes, epidermis with striated cuticle ornamentation, mesophyll with acute borders, presence of druses, secretory channels, angular collenchyma, fibrous pericycle in the stem, intraxylary phloem in the vegetative organs, oil bodies throughout the midrib, petiole, stem and root, and epicuticular waxes of the crust and coiled rodlet types. Since the characters above did not show variation in the environments evaluated, we consider these characters taxonomically useful for the identification of C. umbellata. RESEARCH HIGHLIGHTS: The anatomy of the aerial vegetative organs of Camonnea umbellata retains common Convolvulaceae characters. The sinuosity of the epidermal cell walls and the density of trichomes in the epidermis of the petiole were visually variable characters among the analyzed individuals. Amphistomatic leaves, tetracytic and brachyparatetracytic stomata, peltate trichomes, epidermis with striated cuticle ornamentation, dorsiventral mesophyll with border acute, presence of druses, secretory structures, angular collenchyma, fibrous pericycle in the stem, intraxillary phloem, presence of oil bodies in all organs, and epicuticular waxes of the crust type and coiled rods were considered important anatomical markers for the recognition and correct identification of Camonea umbellata.