scholarly journals Compartmentalization of Metabolites and Enzymatic Mediation in Nutritive Cells of Cecidomyiidae Galls on Piper Arboreum Aubl. (Piperaceae)

2016 ◽  
Vol 6 (1) ◽  
pp. 11 ◽  
Author(s):  
Gracielle Pereira Bragança ◽  
Denis Coelho Oliveira ◽  
Rosy Mary dos Santos Isaias

Galling insects commonly change the chemical profile of their host plant tissues during gall induction and establishment. As a consequence, galls accumulate a wide range of metabolites in specialized cells, which may be organized in a nutritive tissue and in outer storage cells. The nutrients compartmentalized in nutritive cells may be directly assessed or metabolized via enzymatic mediation, while the gall outer cortex may accumulate secondary metabolites. These secondary metabolitesmay configure a specialized chemical barrier against the attack of natural enemies. Either the nutritive inner cells or the outer cortical cells, with their specific metabolic apparatus, should differentiate under the chemical constraints of each host plant-galling herbivore interaction. This premise is herein addressed by the investigation of the histochemical profile of the non-galled leaves and galls induced by Diptera: Cecidomyiidae on Piper arboreum. The spatial compartmentalization of the nutritive and defensive metabolites indicates the new functions assumed during the redifferentiation of the host plant cells. The enzymatic mediation of the primary metabolites by sucrose synthase and invertases favors the nutritive requirements of the galling Cecidomyiidae or the structural maintenance of the gall. The accumulation of secondary metabolites is restrict to the tissue layers not involved in nutrition, and may act in the chemical protection against predators or parasitoids. Current results systematically document metabolites compartmentalization, evidence the impairment of toxic compounds storage in cells surrounding the larval chamber, as well as, detect the redirection of nutritive substances to the site of the Cecidomyiidae feeding. The activity of sucrose synthase is restrict to the nutritive tissue in the galls on Piper arboreum, and reinforces previous detection of this enzyme mediation in carbohydrate metabolism in Cecidomyiidae galls.

2017 ◽  
Vol 65 (5) ◽  
pp. 411 ◽  
Author(s):  
Cibele Souza Bedetti ◽  
Gracielle Pereira Bragança ◽  
Rosy Mary dos Santos Isaias

The cascade of biochemical changes occurring at sites of gall development seems to involve a group of common metabolites in plants, namely, the phenolics. Phenolic accumulation has been commonly related to chemical defence, but their primary role seems to be the regulation of cell hypertrophy in galls. Such regulation implies phenolics–auxin (IAA) association at some cell re-differentiation sites, and determines final gall shapes. Herein, we investigated phenolic and auxin accumulation in four gall systems, grouped in two morphotypes, namely lenticular and globoid, induced on pinnulas of Piptadenia gonoacantha (Mart.) J.F.Macbr. Changes in the direction and type of cell expansion between non-galled pinnula and galls were also evaluated. Galling insects associated to lenticular and globoid gall morphotypes promoted changes in host plant cells, leading to the development of different cell sizes, different degrees of anisotropy, and different directions of cell expansion. The accumulation of IAA–phenolics compartmentalised on the basis of gall morphotype, i.e. in the cells of superior and lateral inferior cortices in the lenticular gall morphotypes, and throughout the outer cortex in the globoid gall morphotypes. The sites of accumulation of IAA and phenolics coincided with the most hypertrophied regions, influencing on the determination of the final gall shape.


2021 ◽  
Vol 7 (12) ◽  
pp. 1004
Author(s):  
Lakshmipriya Perincherry ◽  
Natalia Witaszak ◽  
Monika Urbaniak ◽  
Agnieszka Waśkiewicz ◽  
Łukasz Stępień

Fusarium species present ubiquitously in the environment are capable of infecting a wide range of plant species. They produce several mycotoxins targeted to weaken the host plant. While infecting some resistant plants, the host can alter the expression of toxin-related genes and accumulate no/very low amounts of mycotoxins. The ability of the host plant to modulate the biosynthesis of these toxins is entirely depending on the secondary metabolites produced by the plant, often as a part of systemic acquired resistance (SAR). A major role plays in the family of metabolites called phenyl propanoids, consisting of thousands of natural products, synthesized from the phenylalanine or tyrosine amino acids through a cascade of enzymatic reactions. They are also famous for inhibiting or limiting infection through their antioxidant characteristics. The current study was aimed at identifying the differentially expressed secondary metabolites in resistant (Sokolik) and susceptible (Santana) cultivars of pea (Pisum sativum L.) and understanding their roles in the growth and mycotoxin biosynthesis of two different Fusarium species. Although metabolites such as coumarin, spermidine, p-coumaric acid, isoorientin, and quercetin reduced the growth of the pathogen, a higher level of p-coumaric acid was found to enhance the growth of F. proliferatum strain PEA1. It was also noticeable that the growth of the pathogen did not depend on their ability to produce mycotoxins, as all the metabolites were able to highly inhibit the biosynthesis of fumonisin B1 and beauvericin.


2016 ◽  
Vol 5 (03) ◽  
pp. 4927 ◽  
Author(s):  
Shubhi Srivastava ◽  
Paul A. K.

Plant associated microorganisms that colonize the upper and internal tissues of roots, stems, leaves and flowers of healthy plants without causing any visible harmful or negative effect on their host. Diversity of microbes have been extensively studied in a wide variety of vascular plants and shown to promote plant establishment, growth and development and impart resistance against pathogenic infections. Ferns and their associated microbes have also attracted the attention of the scientific communities as sources of novel bioactive secondary metabolites. The ferns and fern alleles, which are well adapted to diverse environmental conditions, produce various secondary metabolites such as flavonoids, steroids, alkaloids, phenols, triterpenoid compounds, variety of amino acids and fatty acids along with some unique metabolites as adaptive features and are traditionally used for human health and medicine. In this review attention has been focused to prepare a comprehensive account of ethnomedicinal properties of some common ferns and fern alleles. Association of bacteria and fungi in the rhizosphere, phyllosphere and endosphere of these medicinally important ferns and their interaction with the host plant has been emphasized keeping in view their possible biotechnological potentials and applications. The processes of host-microbe interaction leading to establishment and colonization of endophytes are less-well characterized in comparison to rhizospheric and phyllospheric microflora. However, the endophytes are possessing same characteristics as rhizospheric and phyllospheric to stimulate the in vivo synthesis as well as in vitro production of secondary metabolites with a wide range of biological activities such as plant growth promotion by production of phytohormones, siderophores, fixation of nitrogen, and phosphate solubilization. Synthesis of pharmaceutically important products such as anticancer compounds, antioxidants, antimicrobials, antiviral substances and hydrolytic enzymes could be some of the promising areas of research and commercial exploitation.


2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Brahma N. Singh ◽  
Garima Pandey ◽  
Prateeksha ◽  
J. Kumar

With the advent of green pharmaceuticals, the secondary metabolites derived from plants have provided numerous leads for the development of a wide range of therapeutic drugs; however the discovery of new drugs with novel structures has declined in the past few years. Cryptogams including lichens, bryophytes, and pteridophytes represent a group of small terrestrial plants that remain relatively untouched in the drug discovery process though some have been used as ethnomedicines by various tribes worldwide. Studies of their secondary metabolites are recent but reveal unique secondary metabolites which are not synthesized by higher plants. These compounds can have the potential to develop more potential herbal drugs for prevention and treatment of diseases The present article . deals with the secondary metabolites and pharmacological activities of cryptogams with an objective to bring them forth as potential source of biodynamic compounds of therapeutic value.


Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 84
Author(s):  
Laura Rieusset ◽  
Marjolaine Rey ◽  
Florence Gerin ◽  
Florence Wisniewski-Dyé ◽  
Claire Prigent-Combaret ◽  
...  

Roots contain a wide variety of secondary metabolites. Some of them are exudated in the rhizosphere, where they are able to attract and/or control a large diversity of microbial species. In return, the rhizomicrobiota can promote plant health and development. Some rhizobacteria belonging to the Pseudomonas genus are known to produce a wide diversity of secondary metabolites that can exert a biological activity on the host plant and on other soil microorganisms. Nevertheless, the impact of the host plant on the production of bioactive metabolites by Pseudomonas is still poorly understood. To characterize the impact of plants on the secondary metabolism of Pseudomonas, a cross-metabolomic approach has been developed. Five different fluorescent Pseudomonas strains were thus cultivated in the presence of a low concentration of wheat root extracts recovered from three wheat genotypes. Analysis of our metabolomic workflow revealed that the production of several Pseudomonas secondary metabolites was significantly modulated when bacteria were cultivated with root extracts, including metabolites involved in plant-beneficial properties.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4504
Author(s):  
Muhanna Al-shaibani ◽  
Radin Maya Saphira Radin Mohamed ◽  
Nik Sidik ◽  
Hesham Enshasy ◽  
Adel Al-Gheethi ◽  
...  

The current review aims to summarise the biodiversity and biosynthesis of novel secondary metabolites compounds, of the phylum Actinobacteria and the diverse range of secondary metabolites produced that vary depending on its ecological environments they inhabit. Actinobacteria creates a wide range of bioactive substances that can be of great value to public health and the pharmaceutical industry. The literature analysis process for this review was conducted using the VOSviewer software tool to visualise the bibliometric networks of the most relevant databases from the Scopus database in the period between 2010 and 22 March 2021. Screening and exploring the available literature relating to the extreme environments and ecosystems that Actinobacteria inhabit aims to identify new strains of this major microorganism class, producing unique novel bioactive compounds. The knowledge gained from these studies is intended to encourage scientists in the natural product discovery field to identify and characterise novel strains containing various bioactive gene clusters with potential clinical applications. It is evident that Actinobacteria adapted to survive in extreme environments represent an important source of a wide range of bioactive compounds. Actinobacteria have a large number of secondary metabolite biosynthetic gene clusters. They can synthesise thousands of subordinate metabolites with different biological actions such as anti-bacterial, anti-parasitic, anti-fungal, anti-virus, anti-cancer and growth-promoting compounds. These are highly significant economically due to their potential applications in the food, nutrition and health industries and thus support our communities’ well-being.


1979 ◽  
Vol 37 (1) ◽  
pp. 411-442
Author(s):  
A.R. Hardham ◽  
B.E. Gunning

Longitudinal sections of roots of Azolla pinnata R. Br. were prepared for electron microscopy so that cortical microtubules could be counted along the longitudinal walls in cell files in the endodermis, pericycle, and inner and outer cortex, and in sieve and xylem elements. With the exception of the xylem, where there are no transverse cell divisions, each file of cells commences with its initial cell and then possesses a zone of concomitant cell expansion and transverse cell division, followed, after completion of the divisions, by a zone of terminal cell differentiation. The cells augment their population of cortical microtubules as they elongate and divide, showing a net increase of up to 0.6 micron of polymerized microtubule length per min. Two main sub-processes were found: (i) When a longitudinal wall is first formed it is supplied with a higher number of microtubules per unit length of wall than it will have later, when it is being expanded. This initial quota becomes diluted as the second sub-process commences. (ii) The cells interpolate new microtubules at a rate which is characteristic of the cell, and, in the endodermis, of the face of the cell, while the cell elongates. Most cell types thus maintain a set density of cortical microtubules while they elongate and divide. Comparisons of endodermal cells in untreated controls, and roots that had been treated with colchicine, low temperature, or high pressure indicate that the initial quota of microtubules, and the later interpolations, and differentially sensitive to microtuble perturbations. Three types of behaviour, all related to changes in the cell walls, were noted as cortex, xylem and sieve element cells entered their respective phases of cell differentiation. The cortical cells expanded in all dimensions, and the interpolation of microtubules diminished or ceased. The sieve elements continued to elongate, and interpolated at a high rate, reaching unusually high densities of microtubules when the cell walls were being thickened. During this period a net increase of 2.0 micron of polymerized microtubule length per min was calculated. Thereafter interpolation ceased and the density of microtubules declined. The sample applied to developing xylem except that, because wall-thickening is localized rather than widespread, the rise and subsequent fall in the density of microtubules was less marked. The data are discussed in relation to the participation of microtubules in wall deposition and to the hypothesis that cortical microtubules arise in discrete zones along the edges of cells.


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