Influence of auxin and phenolic accumulation on the patterns of cell differentiation in distinct gall morphotypes on Piptadenia gonoacantha (Fabaceae)

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.

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.


2015 ◽  
Vol 63 (7) ◽  
pp. 608 ◽  
Author(s):  
Graziela Fleury ◽  
Bruno G. Ferreira ◽  
Geraldo L. G. Soares ◽  
Denis C. Oliveira ◽  
Rosy M. S. Isaias

The modulation of plant development has been the focus of research on insect galls because galling insects induce distinct shapes to acquire the same necessities, shelter and food. Due to the variety of gall morphotypes, it can be assumed that the key processes for their development rely on plant cells’ morphogenetical potentialities. In the present study we investigated the rosette bud galls induced by Pisphondylia brasiliensis on Guapira opposita to check whether two morphogenetical pathways – the shortening of the internodes and the over differentiation of axillary buds – are independent or whether they are concomitant events towards the morphogenesis of the galls. Biometrical measures were made to test whether the final size of the galls is correlated with the number of inducers per gall. We noted that two patterns of activity were observed in gall meristems: the first differentiated pairs of leaves with opposite phyllotaxy, and the other differentiated new buds at the base of each leafy projection, with the development of sequential leafy projections, in a disorganised phyllotaxy. This second pattern repeated until gall maturation, when a master cambium, typical of the Nyctaginaceae, differentiated in larger galls. The two morphogenetical pathways occurred concomitantly, leading to the overproduction of leafy projections. Cell responses at gall development site produce mechanical protection to P. brasiliensis individuals. The larger galls have the higher number of inducers, and the coalescence of galls allows an increase in gall size by precociously triggering the master cambium activity, a developmental peculiarity of G. opposita uncommon for Cecidomyiidae galls.


Author(s):  
Anthony G. Davies ◽  
Jillian A. Sleep

There is now a substantial body of evidence that the growth rates of phytoplankton in culture are more closely related to the cellular levels of the rate-limiting constituent, be it a nutrient, micronutrient or toxic metal, than to the concentrations in the supporting medium; nitrate, Caperon (1968); phosphate, Fuhs (1969); silicate, Paasche (1973); vitamin B12, Droop (1968); iron, Davies (1970); mercury, Davies (1974); cadmium, Davies (1978a). This has suggested the requirement for a technique which would allow the determination of comparable relationships for natural populations of phytoplankton - how, for instance, their carbon fixation rates depend upon the metal contents of the plant cells. Although the effects of metals upon carbon fixation in phytoplankton assemblages from several different sea areas have already been examined (Knauer & Martin, 1972; Patin et al. 1974; Zingmark & Miller, 1975; Ibragim & Patin, 1976) no data seem to have been obtained on the levels of the metals present in the phytoplankton at the time of the measurements.


2009 ◽  
Vol 58 (S2) ◽  
pp. S244-S248 ◽  
Author(s):  
Daiji Sakata ◽  
Chengcan Yao ◽  
Yoshiyasu Esaki ◽  
Youxian Li ◽  
Toshiyuki Matsuoka ◽  
...  

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.


2006 ◽  
Vol 31 (3) ◽  
pp. 343-348 ◽  
Author(s):  
ANA PAULA ALBANO ARAUJO ◽  
JOANA D'ARC DE PAULA ◽  
MARCO ANTONIO ALVES CARNEIRO ◽  
JOSE HENRIQUE SCHOEREDER

2018 ◽  
Vol 66 (2) ◽  
pp. 161 ◽  
Author(s):  
Elaine Cotrim Costa ◽  
Renê Gonçalves da Silva Carneiro ◽  
Juliana Santos Silva ◽  
Rosy Mary dos Santos Isaias

Analyses of gall biology and development allow determination of morphogenesis events in host-plant organs that are altered by galling insects. Currently, we assume that there is a correlation between Lopesia sp. instars and the alterations in gall tissues on Mimosa gemmulata that generate the gall shape. The development of Lopesia sp. (three larval instars, pupae and adult) correlates positively with gall growth, especially on the anticlinal axis. First-instar larvae are found in galls at the stage of induction, Instar 2 in galls at early growth and development, Instar 3 in galls at late growth and development, pupae in galls at maturation, and the adult emerges from senescent galls. At induction, the larva stimulates cell differentiation in pinnula and pinna-rachis tissues on M. gemmulata. At early growth and development stages, cell division and expansion are increased, and non-glandular trichomes assist gall closing. Homogenous parenchyma and neoformed vascular bundles characterise late growth and development. At maturation, tissues are compartmentalised and cells achieve major expansion through elongation. At senescence, galls open by the falling of trichomes, and mechanical and nutritive cells have thickened walls. The neoformed nutritive tissue nurtures the developing Lopesia sp., whose feeding behaviour influences the direction of cell elongation, predominantly periclinal, determinant for gall bivalve shape.


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