Leaf ontogenesis of Trembleya phlogiformis DC. (Microlicieae, Melastomataceae): functional aspects and indumentum characterization

Leaf ontogenesis is determinant for the establishment and regulation of its structural and functional properties, in addition to being an excellent tool for assignment to different groups of angiosperms. Even though the importance of leaf morphology and anatomy for taxonomic use is well known, few studies have addressed the processes of leaf ontogeny in Melastomataceae. Herein, we sought to define the ontogenetic steps of leaf of Trembleya phlogiformis, highlighting the indumentum, to understand the main functional traits. Shoot apex, young and fully expanded leaves were processed by usual light microscopy procedures. At the first node, leaf primordia are densely covered with trichomes and emergences. The adaxial layer of ground meristem gives rise to the palisade parenchyma, the procambium originates from median layers of ground meristem and the spongy parenchyma develops from abaxial layers of ground meristem. The differentiation of isobilateral mesophyll on leaves of T. phlogiformis, a common feature in Microlicieae, comes from ground meristem stratification. However, T. phlogiformis stands out by showing in the leaf mature spongy parenchyma cells with irregular shapes. The leaf ontogeny reveals distinct mechanisms of cell differentiation and may be important for the establishment of functional adaptive traits.

Contribution to the identification of the species Myrcia hatschbachii D. Legrand (Myrtaceae): anatomical and histochemical analyses

The genus Myrcia is used in folk medicine to treat diabetes. The plants used in folk medicine require morphological and anatomical references to attest to its authenticity. This is the first report of the microscopic study of Myrcia hatschbachii. In this sense, the aim of the present study was to describe the anatomical characteristics, in order to contribute to the species' identification. For anatomical and surface analyses free-hand sections were prepared and observed using optical microscopy, simultaneously some materials were processed and observed under scanning electron microscopy. In addition, histochemical tests were performed. The anatomical features described here correspond with previously reported features found in other species of the genus Myrcia. Furthermore, the following anatomical markers were observed in Myrcia hatschbachii: druses in the spongy parenchyma, concave-convex midrib, heart-shaped petiole, oval-shaped stem, C-shaped vascular bundle in the midrib and open arc shape with invaginated ends in the petiole; phenolic compounds in the phloem and lignified cells in the pith. The results of anatomical and histochemical analyses provide micromorphological and microchemical features that can help in the taxonomy and proper identification of the species.

Anatomical and physiological characteristics of leaves from Eugenia dysenterica DC. can predict nutritional deficiency symptoms

Plants receiving insufficient concentrations of the different essential nutrients may respond symptomatically to this stress. However, when the first visible symptoms of nutritional deficiency appear, plants already exhibit significant changes in their structure. As seedlings of E. dysenterica are important for the recovery of degraded areas and as the fruits of this species are widely exploited commercially, we decided to evaluate whether the omission of nutrients may affect the leaf anatomical ultrastructure, dry matter production and the synthesis of photosynthetic pigments in this plant, in an attempt to use data of this nature to predict symptoms of nutritional deficiency in seedlings of this species. For this purpose, we grow seedlings in a hydroponic system, offering all nutrients and also omitting each nutrient individually. Thus, we evaluated the effect of the omission of each nutrient on the anatomical leaf structure, dry mass production and the synthesis of photosynthetic pigments. Seedlings that grew in the absence of Ca and Mn exhibited compromised spongy parenchyma and mesophyll development, while the omission of K and Mg increased the number of epidermal cells and stomata. Low dry mass production in E. dysenterica was related to the omission of S and Mn, while P, N and Fe deficiencies directly affected the synthesis of pigments. Thus, leaf anatomical and physiological data can predict nutritional deficiency conditions, enabling the user to diagnose the deficiency before the onset of symptoms in E. dysenterica seedlings. Our results may help investigators to understand the effects of nutritional omissions on other native Cerrado plants

The Morphological and Anatomical Traits of the Leaf in Representative Vinca Species Observed on Indoor- and Outdoor-Grown Plants

Morphological and anatomical traits of the Vinca leaf were examined using microscopy techniques. Outdoor Vinca minor and V. herbacea plants and greenhouse cultivated V. major and V. major var. variegata plants had interspecific variations. All Vinca species leaves are hypostomatic. However, except for V. minor leaf, few stomata were also present on the upper epidermis. V. minor leaf had the highest stomatal index and V. major had the lowest, while the distribution of trichomes on the upper epidermis was species-specific. Differentiated palisade and spongy parenchyma tissues were present in all Vinca species’ leaves. However, V. minor and V. herbacea leaves had a more organized anatomical aspect, compared to V. major and V. major var. variegata leaves. Additionally, as a novelty, the cellular to intercellular space ratio of the Vinca leaf’s mesophyll was revealed herein with the help of computational analysis. Lipid droplets of different sizes and aspects were localized in the spongy parenchyma cells. Ultrastructural characteristics of the cuticle and its epicuticular waxes were described for the first time. Moreover, thick layers of cutin seemed to be characteristic of the outdoor plants only. This could be an adaptation to the unpredictable environmental conditions, but nevertheless, it might influence the chemical composition of plants.

Winter Nights during Summer Time: Stress Physiological Response to Ice and the Facilitation of Freezing Cytorrhysis by Elastic Cell Wall Components in the Leaves of a Nival Species

Ranunculus glacialis grows and reproduces successfully, although the snow-free time period is short (2–3 months) and night frosts are frequent. At a nival site (3185 m a.s.l.), we disentangled the interplay between the atmospheric temperature, leaf temperatures, and leaf freezing frequency to assess the actual strain. For a comprehensive understanding, the freezing behavior from the whole plant to the leaf and cellular level and its physiological after-effects as well as cell wall chemistry were studied. The atmospheric temperatures did not mirror the leaf temperatures, which could be 9.3 °C lower. Leaf freezing occurred even when the air temperature was above 0 °C. Ice nucleation at on average −2.6 °C started usually independently in each leaf, as the shoot is deep-seated in unfrozen soil. All the mesophyll cells were subjected to freezing cytorrhysis. Huge ice masses formed in the intercellular spaces of the spongy parenchyma. After thawing, photosynthesis was unaffected regardless of whether ice had formed. The cell walls were pectin-rich and triglycerides occurred, particularly in the spongy parenchyma. At high elevations, atmospheric temperatures fail to predict plant freezing. Shoot burial prevents ice spreading, specific tissue architecture enables ice management, and the flexibility of cell walls allows recurrent freezing cytorrhysis. The peculiar patterning of triglycerides close to ice rewards further investigation.

Foliar anatomy of ten genotypes of the plant Manihot esculenta (Euphorbiaceae)

Introduction: Cassava Manihot esculenta (Crantz) is a perennial shrub native to South America that is an essential source of carbohydrates for more than 600 million people in tropical countries. Objective: The aim of this study was to describe and compare the leaf blade anatomy of ten genotypes of cassava. Methods: The methodology for anatomical descriptions was processed and 30 leaves of each of the varieties were included and sectioned according to paraffin impregnation protocols. Results: The results showed that the leaf blade anatomical structure of all the varieties in general terms show differences. All varieties had monostratified epidermis, leaf mesophyll consisted of a palisade parenchyma in a single layer and multiple layers of spongy parenchyma. Polyphenolic idioblasts were observed immersed in the palisade parenchyma and spongy parenchyma. Between 3-7 xylem ribs with their respective phloem were found in the midrib in almost all varieties. Trichomes were only found in two varieties (NAT31-ECU72) and leaves were all hipostomatic. Conclusions: The results reveal that NAT31 is the material with the most anatomically marked differences (i.e. presence of trichomes, papillary cell, and, on the adaxial face, special provision in the arrangement of stomata and epicuticle wax patterns), characteristics that might be related to pest resistance.

Anatomical aspects of the ginger flower Etlingera elatior (Jack.) RM Smith, acclimatization with the usage of different nutritive solutions

The Ginger flower, Etlingera elatior (Jack.) RM Smith (also known as torch ginger, ginger flower, red ginger lily, torch lily, wild ginger), belonging to the Zingiberaceae family, stands out with one of the main ornamental tropical species. The objectives of the present study were to establish an acclimatization methodology for in vitro cultivated cane seedlings, and to compare the internal structure of leaves of seedlings submitted to different nutrient solutions. The seedlings from the in vitro culture were transplanted into trays with inert substrate (expanded vermiculite + 10% sand), where they remained in a growth room with controlled temperature of 25 ± 2 °C and photon irradiance of 67 μm m-2 s-1. Moisture control was carried out by using a transparent plastic bag, which was removed after 15 days and shortly thereafter, the experiments were started with the use of nutritive solutions MS (Murashige & Skoog), BJ (Bolle-Jones) and HO (Hoagland & Arnon) at 35% of their ionic strength. For the anatomical study, transverse and paradermal sections were realized in the foliar laminae of seedlings in vitro, in period of acclimatization and in plants already established. The in vitro seedlings showed survival at 100% when transferred to the ex vitro condition. In the cross sections and leaf parser, anatomical differences between the seedlings of the different environments were observed. The abaxial and adaxial epidermis presented significant differences in the environments in which the seedlings developed, showing themselves to be thicker as the acclimatization period increased. The thickness averages of the palisade parenchyma did not differ statistically in the acclimatization periods and in the different nutrient solutions tested. On the other hand, those ones of the spongy parenchyma´s presented significant differences in relation to the nutrient solutions tested, evidencing in all evaluations the MS solution, which contributed the most to the development of the internal structures of the leaf (spongy parenchyma and central vascular cylinder). The highest stomatal density was observed in seedlings developed in vitro (250 stomata per mm2) when compared to those ones already acclimatized or even to that one of field, 200 and 190 stomata per mm2 respectively. The stomata of the Ginger flower leaves developed in vitro presented with polar and equatorial diameters greater than the stomata of leaves already acclimatized and as well as of field.

Leaf Morphoanatomy and Biochemical Variation on Coffee Cultivars Under Drift Simulation of Glyphosate

ABSTRACT: The most widely used herbicide in coffee crop is glyphosate, it inhibits the biosynthesis of secondary metabolites, responsible for structures and substances of plant defense. This work aimed to evaluate the morphoanatomy, total phenols, flavonoids and caffeine in leaves of Arabica coffee submitted to different sub-doses of glyphosate. The treatments were combinations of three coffee cultivars (MGS Travessia, Oeiras MG 6851 and Catuaí IAC 144) and five sub-doses of glyphosate (0.0, 57.6, 115.2, 230.4 and 460.8 g a.e. ha-1). The total thickness of the leaf blade, thickness of adaxial and abaxial epidermis, palisade and spongy parenchyma, in addition to the total phenol, total flavonoids and caffeine were evaluated 30 days after spraying. Catuaí showed a reduction in the total leaf thickness, while the others cultivars had an increase. The thickness of adaxial and abaxial epidermis and palisade parenchyma was reduced, and the spongy parenchyma increased with increasing doses of glyphosate, regardless of the cultivars. There was an increase on the total phenols up to 115.2 g ha-1 glyphosate, and above this dose, the concentrations of phenols were reduced. The Travessia and Oeiras cultivars obtained a reduction of flavonoids up to 115.2 g ha-1; and above this dose, the concentration of flavonoids increased. The Catuaí cultivar showed an opposing behavior of the concentration of flavonoids. Oeiras and Catuaí showed a decrease of caffeine up to 115.2 g ha-1 and an increase at higher doses. Travessia showed an increase of caffeine in sub-doses above 115.2 g ha-1. The three cultivars showed a higher concentration of phenols in the palisade parenchyma after the application of glyphosate drift. Glyphosate reduces the thickness of the adaxial and abaxial epidermis and palisade parenchyma, and increases the thickness of spongy parenchyma. Doses of glyphosate above 230.4 g ha-1 result in the reduction of total phenols. The concentration of flavonoids and caffeine has varying effects with glyphosate application.

STRUCTURAL EVALUATION OF DAMAGE CAUSED BY HERBICIDE CLOMAZONE IN LEAVES OF ARBORESCENT SPECIES NATIVE TO BRAZIL

ABSTRACT Herbicide clomazone is highly soluble in water, which increases the risk of leaching, resulting in contamination of sources of groundwater and waterways, affecting non-target organisms, with possible degradation of riparian areas. The objective of this work was to investigate the possible anatomical modifications of the leaf tissue of twelve arborescent species native to Brazil grown in soil contaminated by clomazone, in order to microscopically characterize leaf damage caused by the herbicide, and investigate whether the structural damage precedes visible damage. Through micro morphometrics, the thickness and the area occupied by the tissues were measured in a cross section of the leaves of the forest species: adaxial and abaxial epidermis, palisade and spongy parenchyma. It has been found that the species evaluated were affected by the presence of the pesticide in the soil, and the variable with the largest negative changes was the spongy parenchyma. Among the species, Inga marginata, Schizolobium parahyba and Handroantus. serratifolius had higher tolerance to the herbicide, demonstrating potential for studies on the mechanism by which these plants exert such tolerance. Overall, the results revealed that the forest species studied demonstrate significant alterations in leaf anatomy in response to the presence of residues of herbicide clomazone in the soil, even in leaves with no visible lesions.

Schaffneria nigripes (Aspleniaceae): morfogénesis del gametofito y anatomía y morfológía del esporofito

Data about the morphology and anatomy of the sporophyte and the gametophyte development of Schaffncria nigripes Fée (Asplcniaceae) are given in this paper; the leaves are entire, rhomboid to obovate, with stomata in the abaxial side of the lamina; the mesophyll is a spongy parenchyma; the stele, with a well defined endodermis, is an ectophloic siphonostele. The spores have long viability and the germination is Vittaria type; the mature gametophytes are irregularly cordate, with non-glandular hairs in both surfaces and in the margins.