Showing papers by "Denis Coelho de Oliveira published in 2019"
01 Jan 2019
15 citations
TL;DR: Gall morphotypes depend on continuous chemical and feeding stimuli of the gall inducer, which promotes specific structural and metabolic changes in plant tissues, and the galling insect manipulates these stimuli.
Abstract: Gall morphotypes depend on continuous chemical and feeding stimuli of the gall inducer, which promotes specific structural and metabolic changes in plant tissues. The galling insect manipulates hos...
11 citations
TL;DR: This is the first study to demonstrate quantitatively why the galls of a specific species may be coloured: the variation in light regimes creates differential anthocyanin accumulation, influencing coloration.
Abstract: Several studies have suggested reasons why galls have conspicuous colours, but none of the ideas have been confirmed. However, what if the vibrant colours of some galls are explained simply by the effect of light exposure? This may lead to anthocyanin accumulation, functioning as a defence mechanism against the effects of high light. We studied the globoid galls induced by Cecidomyiidae (Diptera) on Qualea parviflora (Vochysiaceae), relating anthocyanin accumulation and chlorophyll fluorescence parameters to light incidence in abaxial and adaxial galls. We also tested if the anthocyanin accumulation patterns apply to another Cecidomyiidae-induced gall morphotype (intralaminar) within the same plant. Adaxial galls are exposed to higher incident light, with more anthocyanin accumulation and therefore red coloration. In galls from angled leaves, the greater the angle of the leaf, the higher the difference between anthocyanins on the sun and shade sides of galls. Photosynthetic pigment concentrations did not differ between abaxial and adaxial galls. However, we found higher (Fm ' - F')/Fm ' and Fv /Fm in the abaxial galls. Conversely, NPQ and Rfd were higher in adaxial galls. Finally, the pattern of anthocyanin accumulation was not found in the intralaminar gall. Anthocyanin accumulation in galls functions as a photoprotective strategy, maintaining tissue vitality in regions exposed to high light conditions. However, this mechanism may vary even among galls within the same host, indicating idiosyncrasy when it comes to coloration in galls. To date, this is the first study to demonstrate quantitatively why the galls of a specific species may be coloured: the variation in light regimes creates differential anthocyanin accumulation, influencing coloration.
11 citations
TL;DR: The increased labeling of homogalacturonan epitopes, especially in senescent galls, is a clear indicator that pectin methylesterase activity is maintained despite oxidative stresses imposed by the galling insect.
9 citations
TL;DR: The original version of this article unfortunately contains an error and the correct caption of Figures 2 and 3 are shown.
Abstract: The original version of this article unfortunately contains an error. The correct caption of Figures 2 and 3 are shown in this paper.
8 citations
TL;DR: Histological, cytological, histochemical and anatomical changes during the establishment and development of galls and giant cells induced by Meloidogyne javanica in the roots of Glycine max showed a disorganisation of the cells of the cortex and vascular cylinder in relation to the control root.
Abstract: Galls formed by root-knot nematodes have been studied in several cultivated species focusing on understanding the intimate relationship between parasite and the host plant. Species of Meloidogyne induce the development of a feeding site in the cortex or vascular cylinder of the host plant and are totally dependent on this site formation to complete their life cycle. Therefore, we focused on anatomical, cytological and histochemical changes during the establishment and development of galls and giant cells induced by Meloidogyne javanica in the roots of Glycine max. Seeds of soybean (susceptible cultivar M8372 IPRO) were sown in trays with coconut fibre substrate and the seedlings were removed ten days after the seeds emerged for nematode inoculation. The roots from inoculated and non-inoculated (control) were sampled at different stages of development until 55 days after inoculation. Histological, cytological, histochemical analysis were performed in light and electron microscopy in non-galled tissue and galls induced by M. javanica. The galls showed different shapes and abundance in the roots inoculated by M. javanica. The induction of galls occurs by hypertrophy of the root cortex shortly after the initial infection process. Giant cells were formed 18 days after nematode inoculation. These giant or nourishing cells are multinucleated, and have a dense cytoplasm, a thick wall with invaginations, many mitochondria and small vacuoles. The anatomical sections indicated a disorganisation of the cells of the cortex and vascular cylinder in relation to the control root.
6 citations
TL;DR: Different from other described species of Allorhogas that induce galls on fruits/seeds of Melastomataceae, the new species attacks floral bud ovules of Miconia chamissois Naudin, forming ‘fruit-like’ galls.
Abstract: Allorhogas Gahan (Hymenoptera: Braconidae) is a mainly Neotropical doryctine wasp genus whose species have been associated with 11 vascular plant families. All species of Allorhogas whose f...
6 citations
TL;DR: Galling herbivore-induced volatiles may exhibit robust effects on neighboring-plant interactions including those ones during different plant developmental or phenological periods, and information about multitrophic interactions between insects and plants is provided.
Abstract: The galling insect manipulates the host plant tissue to its own benefit, building the gall structure where it spends during most of its life cycle. These specialist herbivore insects can induce and manipulate plant structure and metabolism throughout gall development and may affect plant volatile emission. Consequently, volatile emission from altered metabolism contribute to eavesdropping cueing. Eavesdropping can be part of adaptive strategies used by evolution for both galling insects and the entire-associated community in order to cue some interaction response. This is in contrast to some herbivores associated with delayed induced responses, altering plant metabolites during the short time while they feed. Due to the different lifestyles of the galling organism, which are associated with different plant tissues and organs (e.g leaves, flowers or fruits), a distinct diversity of organisms may eavesdrop on induced volatiles interacting with the galls. Furthermore, the eavesdropping cues may be defined according to the phenological coupling between galling organism and host plant, which results from the development of a gall structure. For instance, when plants release volatile-induced defenses after galling insects' activity, another interactor may perceive these volatiles and change its behavior and interactions with host plants and galls. Thus, natural enemies could be attracted by different volatiles emitted by the gall tissues. Considering the duration of the life cycle of the galling organism and the gall, the temporal extent of gall-induced volatiles may include more persistent volatile cues and eavesdropping effects than the volatiles induced by non-galling herbivores. Accordingly, from chemical ecology perspective we expect that galling herbivore-induced volatiles may exhibit robust effects on neighboring-plant interactions including those ones during different plant developmental or phenological periods. Information about multitrophic interactions between insects and plants supports the additional understanding of direct and indirect effects, and allows insight into new hypotheses.
5 citations
TL;DR: The Ceropsylla pouteriae gall develops from cellular hypertrophy and hyperplasia of the mesophyll leaf tissue, as well as neoformation of vascular tissues, which leads to the formation of the adaxial cortex of the gall.
Abstract: Ceropsylla pouteriae Burckhardt sp. nov. is described and illustrated from Brazil: Minas Gerais. It induces pit galls on the leaves of Pouteria ramiflora (Mart.) Radlk. (Sapotaceae), a characteristic tree of the Cerrado biome. The previously artificial genus Ceropsylla is redefined and six species are transferred from Ceropsylla to Trioza as Trioza angustirerta (Li, 2011), comb. nov., Trioza celticola (Li, 2011), comb. nov., Trioza cestolemba (Li, 2011), comb. nov., Trioza discrepans (Tuthill, 1945), comb. nov., Trioza martorelli (Caldwell, 1942), comb. nov. and Trioza pulchra (Tuthill, 1945), comb. nov. The psyllids on Sapotaceae are reviewed and the phylogenetic relationships of Ceropsylla briefly discussed. The Ceropsylla pouteriae gall develops from cellular hypertrophy and hyperplasia of the mesophyll leaf tissue, as well as neoformation of vascular tissues. The hypertrophy of the palisade parenchyma cells leads to the formation of the adaxial cortex of the gall. The abaxial cortex originates from the spongy parenchyma. The elongation of the adaxial and abaxial cortex is responsible for the intralaminar gall shape. The neoformation of vascular bundles is an important feature for the phloem feeding Ceropsylla pouteriae. The intralaminar morphotype of the C. pouteriae gall showed a simple anatomical structure. It lacks defence-related compounds and nutritive tissue. The structural simplicity contrasts with the presence of chemical substances in the gall tissue.
4 citations
TL;DR: Cell wall composition in leaf tissues of Lavoisiera mucorifera is evaluated and it was showed that the distribution of cell wall components depends on tissue and leaf developmental stage.
Abstract: How does the deposition of cell wall components structure cell shape and function during leaf ontogenesis? Although this issue has been the subject of several studies, a wide variety of standards have been reported and many knowledge gaps remain. In this study we evaluated cell wall composition in leaf tissues of Lavoisiera mucorifera Mart. & Schrank ex DC. (Melastomataceae) regarding cellulose, pectin (homogalacturonans (HGs) and rhamnogalacturonans I (RGI)) and arabinogalactan protein (AGP) distribution during ontogenesis. Leaf primordium, as well as young and mature leaves, were submitted to histochemical analysis using calcofluor white and ruthenium red, and immunocytochemical analysis using primary monoclonal antibodies (JIM5, JIM7, LM2, LM5 and LM6). Results showed that the distribution of cell wall components depends on tissue and leaf developmental stage. At the beginning of cell differentiation in the leaf primordium, two main patterns of cellulose microfibril orientation occur: perpendicular and random. This initial microfibril arrangement determines final cell shape and leaf tissue functionality in mature leaves. During leaf development, especially in epidermal and collenchyma cells, the association of HGs with low methyl-esterified groups and cellulose guarantees mechanical support. As a result, cell wall properties, such as rigidity and porosity, may also be acquired by changes in cell wall composition and are associated with morphogenetic patterns in L. mucorifera.