Internal secretory spaces in thickened underground systems of Asteraceae species

2009 ◽  
Vol 57 (3) ◽  
pp. 229 ◽  
Author(s):  
Graziela Cury ◽  
Beatriz Appezzato-da-Glória
Keyword(s):  
Vascular Plants ◽  
Chemical Nature ◽  
Secondary Xylem ◽  
Plant Defence ◽  
Tropical Savanna ◽  
Defence Mechanism ◽  
Secondary Phloem ◽  
Secretory Structures ◽  
Histochemical Tests ◽  
Aerial Systems

Secretory structures are present in many vascular plants and have an important ecological role as a plant defence mechanism against herbivors and pathogens. Internal secretory spaces of lipid substances are widespread in the Asteraceae. However, information about the occurrence of these structures in thickened underground systems is sparse, compared with what we know about aerial systems. The main objective of the present paper was to investigate the occurrence, formation and chemical nature of the secretory structures in six Asteraceae species belonging to the following tribes: Eupatorieae (Mikania cordifolia and M. sessilifolia), Mutisiae (Trixis nobilis), Plucheeae (Pterocaulon alopecuroides) and Vernonieae (Vernonia elegans and V. megapotamica). The samples were collected in areas of Cerrado (tropical savanna) in the state of São Paulo, Brazil. The secretory structures found were cortical canals in roots (T. nobilis, P. alopecuroides, V. elegans and V. megapotamica), cortical cavities in roots (M. cordifolia, M. sessilifolia and P. alopecuroides), cavities in the secondary phloem of roots (T. nobilis), cortical cavities in the xylopodium (M. cordifolia, M. sessilifolia, P. alopecuroides and V. megapotamica) and in the underground stem (T. nobilis), and canals in the secondary xylem in the xylopodium (M. cordifolia and M. sessilifolia). Histochemical tests showed the presence of lipid substances in all structures.

Localization of phenols and polyphenol oxidase in 'Jewel' sweet potatoes (Ipomoea batatas 'Jewel')

1981 ◽  
Vol 59 (10) ◽  
pp. 1961-1967 ◽  
Author(s):  
W. E. Schadel ◽  
W. M. Walter Jr.
Keyword(s):  
Phenolic Compounds ◽  
Polyphenol Oxidase ◽  
Ipomoea Batatas ◽  
Secondary Xylem ◽  
Root Tissue ◽  
Secondary Phloem ◽  
Sweet Potatoes ◽  
Parenchyma Cells ◽  
Histochemical Tests ◽  
Xylem Elements

Histochemical tests for phenols and polyphenol oxidase were performed on fresh root tissue of Ipomoea batatas (L.) Lam. 'Jewel.' The phenolic compounds were localized in the phellem, phellogen, and phelloderm, in approximately 1 mm (ca. 10–15 cells) of the tissue directly beneath the periderm, in the latex of laticifers, in the phloem, in the cambium which separates the secondary phloem from the secondary xylem, in the anomalous secondary cambia of the central core, in the parenchyma cells adjacent to the xylem elements, and in the walls of the xylem elements. Polyphenol oxidase was localized primarily in the phellogen and phelloderm and most prominently in the latex of laticifers.

Wood and Bark Anatomy of Lauraceae. ii. Licaria Aublet

IAWA Journal ◽  
1985 ◽  
Vol 6 (3) ◽  
pp. 187-199 ◽  
Author(s):  
Hans Georg Richter
Keyword(s):  
Diagnostic Tool ◽  
Secondary Xylem ◽  
Secondary Phloem ◽  
Structural Profile ◽  
Quantitative Characters ◽  
Important Diagnostic Tool ◽  
Species Groups ◽  
Bark Anatomy

Qualitative features of the secondary xylem of Licaria present a rather uniform structural profile. Constant differences in primarily quantitative characters lead to the formation of speeies groups wh ich loosely correspond to infrageneric sections based on floral and vegetative morphology. This subdivision is strongly corroborated by the highly variable secondary phloem structurc revealing considerable diversity in type and distribution of sc1erenchymatic tissues. Inorganic inclusions in the secondary xylem, crystals and silica, constitute an important diagnostic tool for differentiating certain species and species groups, but are hardly of importance in the bark.

scholarly journals Floral morphology and anatomy of Dalechampia alata Klotzsch ex Baill. (Euphorbiaceae), with emphasis on secretory structures

2016 ◽  
Vol 76 (1) ◽  
pp. 233-244 ◽  
Author(s):  
F. M. Martins ◽  
I. L. Cunha-Neto ◽  
T. M. Pereira
Keyword(s):  
Light Microscope ◽  
Chemical Nature ◽  
Floral Morphology ◽  
Staminate Flower ◽  
Ovary Wall ◽  
Transmitting Tissue ◽  
Secretory Structures ◽  
First Report ◽  
Meristematic Activity ◽  
Secretory Glands

Abstract The morphology and anatomy of the flower of Dalechampia alata, as well as the chemical nature of the exudates secreted in the inflorescence were studied using light microscope. This is the first report showing the presence of colleters in the genus Dalechampia. In the staminate flower occur a group of small secretory glands. The histochemical results indicate that the substance secreted from the glands is lipidic and resinuous in nature, while in the colleters it consists of polysaccharides and lipid-rich substances. The ovule of D. alata are anatropous, subglobose and bitegmic. It presents obturator, micropyle occluded by nucellar beak and meristematic activity in the ovary wall. The secretion produced in the stigmatic and transmitting tissue consists of polysaccharides.

scholarly journals RESILIENCE OF FERNS: WITH REFERENCE TO DESICCATION AND REHYDRATION STRESS OFFER NEW INSIGHTS

2017 ◽  
Vol 4 (2) ◽  
pp. 89-94
Author(s):  
Kavitha C.H ◽  
Meenu Krishnan ◽  
Murugan K
Keyword(s):  
Vascular Plants ◽  
Stress Proteins ◽  
Secondary Xylem ◽  
Plant Water Relations ◽  
Vascular Bundles ◽  
Late Cenozoic ◽  
Primary Xylem ◽  
Hydraulic Failure ◽  
Pit Membrane ◽  
Selection For

Ferns are one of the oldest vascular plants in existence and they are the second most diverse group of vascular plants followed to angiosperms. To unravel fern success has focused on the eco-physiological power and stress tolerance of their sporophyte and the gametophyte generations. In this context, those insightsencompass plant water relations, as well as the tolerance to and recovery from drought or desiccation stresses in the fern life cycle are reviewed. Lack of secondary xylem in ferns is compensated by selection for efficient primary xylem composed of large, closely arranged tracheids with permeable pit membranes.Protection from drought-induced hydraulic failure appears to arise from a combination of pit membrane traits and the arrangement of vascular bundles. Features such as tracheid-based xylem and variously sized megaphylls are shared between ferns and more derived lineages, and offer an opportunity to compare convergent and divergent hydraulic strategies critical to the success of xylem-bearing plants. Similarly the synthesis and accumulation of sugar, proline and stress proteins along with the production of pool of polyphenols add strength to desiccation stress. Thus, it can possible to suggest that selection acted on the physiology in a synchronous manner that is consistent with selection for drought tolerance in the epiphytic niche, and the increasingly diverse habitats of the mid to late Cenozoic.

scholarly journals The Biosynthesis of Phenolic Compounds Is an Integrated Defence Mechanism to Prevent Ozone Injury in Salvia officinalis

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1274
Author(s):  
Alessandra Marchica ◽  
Lorenzo Cotrozzi ◽  
Rebecca Detti ◽  
Giacomo Lorenzini ◽  
Elisa Pellegrini ◽  
...  
Keyword(s):  
Plant Defence ◽  
Phenol Oxidase ◽  
Tyrosine Aminotransferase ◽  
Phenylpropanoid Metabolism ◽  
Defence Mechanism ◽  
Ozone Injury ◽  
End Of Treatment ◽  
Oxidative Damage To Proteins ◽  
Induced Changes ◽  
Rosmarinic Acid Synthase

Specialized metabolites constitute a major antioxidant system involved in plant defence against environmental constraints, such as tropospheric ozone (O3). The objective of this experiment was to give a thorough description of the effects of an O3 pulse (120 ppb, 5 h) on the phenylpropanoid metabolism of sage, at both biochemical and molecular levels. Variable O3-induced changes were observed over time among the detected phenylpropanoid compounds (mostly identified as phenolic acids and flavonoids), likely because of their extraordinary functional diversity. Furthermore, decreases in the phenylalanine ammonia-lyase (PAL), phenol oxidase (PPO), and rosmarinic acid synthase (RAS) activities were reported during the first hours of treatment, probably due to an O3-induced oxidative damage to proteins. Both PAL and PPO activities were also suppressed at 24 h from the beginning of exposure, whereas enhanced RAS activity occurred at the end of treatment and at the recovery time, suggesting that specific branches of the phenolic pathways were activated. The increased RAS activity was accompanied by the up-regulation of the transcript levels of genes like RAS, tyrosine aminotransferase, and cinnamic acid 4-hydroxylase. In conclusion, sage faced the O3 pulse by regulating the activation of the phenolic biosynthetic route as an integrated defence mechanism.

REACTION TISSUES IN GNETUM GNEMON A PRELIMINARY REPORT

IAWA Journal ◽  
2001 ◽  
Vol 22 (4) ◽  
pp. 401-413 ◽  
Author(s):  
P. B. Tomlinson
Keyword(s):  
Cell Walls ◽  
Tension Wood ◽  
Secondary Xylem ◽  
Secondary Phloem ◽  
Outer Cortex ◽  
Cortical Cells ◽  
Wood Fibres ◽  
Developmental Feature ◽  
Gnetum Gnemon ◽  
Clear Differentiation

Gnetum gnemon exhibits Rouxʼs model of tree architecture, with clear differentiation of orthotropic from plagiotropic axes. All axes have similar anatomy and react to displacement in the same way. Secondary xylem of displaced stems shows little eccentricity of development and no reaction anatomy. In contrast, there is considerable eccentricity in extra-xylary tissue involving both primary and secondary production of apparent tension-wood fibres (gelatinous fibres) of three main kinds. Narrow primary fibres occur concentrically in all axes in the outer cortex as a normal developmental feature. In displaced axes gelatinous fibres are developed abundantly and eccentrically on the topographically upper side, from pre-existing and previously undetermined primary cortical cells. They are wide with lamellate cell walls. In addition narrow secondary phloem fibres are also differentiated abundantly and eccentrically on the upper side of displaced axes. These gelatinous fibres are narrow and without obviously lamellate cell walls. Eccentric gelatinous fibres thus occupy a position that suggests they have the function of tension wood fibres as found in angiosperms. This may be the first report in a gymnosperm of fibres with tension capability. Gnetum gne-mon thus exhibits reaction tissues of unique types, which are neither gymnospermous nor angiospermous. Reaction tissues seem important in maintaining the distinctive architecture of the tree.

Anatomical characterisation of the foliar colleters in Myrtoideae (Myrtaceae)

2012 ◽  
Vol 60 (8) ◽  
pp. 707 ◽  
Author(s):  
Cleber J. da Silva ◽  
Luiz Cláudio de A. Barbosa ◽  
Ana E. Marques ◽  
Maria Cristina Baracat-Pereira ◽  
Antônio L. Pinheiro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phylogenetic Relationships ◽  
External Morphology ◽  
Secretory Structures ◽  
Reproductive Shoot ◽  
Sds Page ◽  
Histochemical Tests ◽  
Five Tribes ◽  
Scanning Electron

Colleters are secretory structures that occur in vegetative or reproductive shoot apices of many botanical families. However, in the order Myrtales, reports of colleters have considered only external morphology. We therefore evaluated apical meristems of 52 species belonging to 17 genera from seven tribes of subfamily Myrtoideae (Myrtaceae), so as to analyse the incidence and morphological types of colleters. The samples were fixed for light and scanning electron microscopy. Histochemical tests were carried out on fresh and methacrylate-embedded material. Proteins of the colleter secretions were analysed by SDS-PAGE. We have classified and described the following three new colleter types: petaloid, conic and euryform. None of the species contained all three colleter types. The petaloid colleters were present in three tribes (Syzygieae, Melaleuceae and Lophostemoneae). The conic colleters were observed in three tribes (Leptospermeae, Myrteae and Melaleuceae) and the euryform type occurred in five tribes (Leptospermeae, Syncarpieae, Myrteae, Syzygieae and Melaleuceae). In the tribe Eucalypteae, we found no evidence of colleters. The presence of mucilaginous secretion that defines colleters was confirmed by histochemical tests, and no proteins were found in the secretion. The colleters in Myrtoideae may help clarify the phylogenetic relationships of the Myrtaceae family.

Development of Included Phloem in the Stem of Combretum Nigricans (Combretaceae)

IAWA Journal ◽  
1995 ◽  
Vol 16 (2) ◽  
pp. 151-158 ◽  
Author(s):  
R. W. den Outer ◽  
W. L. H. van Veenendaal
Keyword(s):  
Secondary Xylem ◽  
Vascular Cambium ◽  
Secondary Phloem ◽  
Xylem Parenchyma ◽  
Long Period ◽  
Short Period ◽  
Outer Border

The development of diffuse included phloem strands in Combretum nigricans sterns is described, During a short period of time, a small phloem strand is cut off locally in an inward direction by an otherwise normal bidirectional vascular cambium. This contrasts with previous descriptions and interpretations because these strands are not formed after redifferentiation of secondary xylem parenchyma. A complementary cambium formed at the inner border of the young strand somewhat enlarges the strand and, during a relatively long period, produces secondary phloem outwards. Finally this complementary cambium stops functioning as a cambium and merges with the secondary phloem it has produced. Radial rows of cells are present within the included phloem strands which continue into the later-formed secondary xylem; rays transverse the strands. Crushing of the phloem takes place near the outer border of the strand, forming cap-like tissues of disorganized cells.

Laticifers of Ficus Carica and Their Potential Role in Plant Defense

IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 109-115 ◽  
Author(s):  
C. Kajii ◽  
T. Morita ◽  
K. Kuroda
Keyword(s):  
Potential Role ◽  
Secondary Xylem ◽  
Nile Blue ◽  
Ficus Carica ◽  
Secondary Phloem ◽  
Fast Green ◽  
Cambial Zone ◽  
A Current ◽  
Latex Production

The distribution and structure of laticifers in Ficus carica L. were investigated in a current-year branch and an 8-year-old trunk, using serial sections stained with safranin-fast green or nile blue. In the 8-year-old trunk, laticifers were found not only in the cortex, secondary phloem, and pith, but also in the secondary xylem. The laticifers in the phloem and xylem were of the branched, non-articulated type. In addition, horizontal laticifers extending from the phloem through the cambium to the xylem were found in some rays. Laticifers penetrating the cambial initial layer elongated in the cambial zone without cell division. Activation of latex production occurred after wounding of cortex and phloem, and the latex exuded from the cut site of laticifers into the surrounding wounded tissue and broken cells. The potential role of laticifers in defense of F. carica against certain pathogens is discussed.

scholarly journals Foliar colleters in Macrocarpaea obtusifolia (Gentianaceae): anatomy, ontogeny, and secretion

Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Valdnéa Casagrande Dalvi ◽  
Lucas Siqueira Cardinelli ◽  
Renata Maria Strozi Alves Meira ◽  
Aristéa Alves Azevedo
Keyword(s):  
Chemical Nature ◽  
Developmental Stages ◽  
Structure And Function ◽  
Histochemical Analysis ◽  
Secretory Structures ◽  
Standard Type ◽  
Vegetative Organs ◽  
New Information ◽  
And Function ◽  
First Time

Colleters are secretory structures located in reproductive and (or) vegetative organs of many eudicots. In Gentianaceae Juss., the presence of foliar colleters has been neglected, and anatomical and histochemical studies are scarce. The objectives of this study were to investigate the anatomy, ontogeny, and chemical nature of the secretion found in Macrocarpaea obtusifolia (Griseb.) Gilg colleters to establish a relationship between their structure and function and check whether these structures are similar to those described for other genera of the Gentianaceae and other families of the Gentianales. Samples of leaves at different developmental stages were collected and processed for anatomical and histochemical analysis using light microscopy and scanning electron microscopy. Colleters in M. obtusifolia have a protodermal origin, are of standard type, and are not vascularized. Young colleters are translucent and produce an abundant amount of sticky secretion. Later, they turn yellowish with a blackened region at the apex of the head, and the secretion, composed of polysaccharides and proteins, becomes less abundant and brownish. During senescence, the process begins with complete degradation and cell collapse of the secretory portion. The colleters of the standard type in M. obtusifolia have been observed for the first time in the Gentianaceae and represent additional evidence that reinforces how common this type of colleter is in the Gentianales. Such results provide new information on the anatomy, ontogeny, histochemistry, and colleter types of Gentianaceae.

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