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In Metrodorea nigra, a Rutaceae species with rhythmic growth, the shoot apex in the dormant stage is enclosed by modified stipules. The young organs are fully covered with peltate secretory trichomes, and these structures remain immersed in a hyaline exudate within a hood-shaped structure. Our study focused on the morpho-functional characterization of the peltate trichomes and cytological events associated with secretion. Shoot apices were collected during both dormant and active stages and processed for anatomical, cytochemical and ultrastructural studies. Trichomes initiate secretion early on, remain active throughout leaf development, but collapse as the leaves expand; at which time secretory cavities start differentiation in the mesophyll and secretion increases as the leaf reaches full expansion. The subcellular apparatus of the trichome head cells is consistent with hydrophilic and lipophilic secretion. Secretion involves two vesicle types: the smaller vesicles are PATAg-positive (periodic acid/thiocarbohydrazide/silver proteinate) for carbohydrates and the larger ones are PATAg-negative. In the first phase of secretory activity, the vesicles containing polysaccharides discharge their contents through exocytosis with the secretion accumulating beneath the cuticle, which detaches from the cell wall. Later, a massive discharge of lipophilic substances (lipids and terpenes/phenols) results in their accumulation between the wall and cuticle. Release of the secretions occurs throughout the cuticular microchannels. Continued protection of the leaves throughout shoot development is ensured by replacement of the collapsed secretory trichomes by oil-secreting cavities. Our findings provide new perspectives for understanding secretion regulation in shoot apices of woody species with rhythmic growth.

Nuptial and extranuptial nectaries are involved in interactions with different animal functional groups. Nectar traits involved in pollination mutualisms are well known. However, we know little about those traits involved in other mutualisms, such as ant–plant interactions, especially when both types of nectaries are in the same plant organ, the flower. Here we investigated if when two types of nectaries are exploited by distinct functional groups of floral visitors, even being within the same plant organ, the nectar secreted presents distinct features that fit animal requirements. We compared nectar secretion dynamics, floral visitors and nectar chemical composition of both nuptial and extranuptial nectaries in natural populations of the liana Amphilophium mansoanum (Bignoniaceae). For that we characterized nectar sugar, amino acid and specialized metabolite composition by high-performance liquid chromatography. Nuptial nectaries were visited by three medium- and large-sized bee species and extranuptial nectaries were visited mainly by ants, but also by cockroaches, wasps and flies. Nuptial and extranuptial nectar differed regarding volume, concentration, milligrams of sugars per flower and secretion dynamics. Nuptial nectar was sucrose-dominated, with high amounts of γ-aminobutyric acid and β-aminobutyric acid and with theophylline-like alkaloid, which were all exclusive of nuptial nectar. Whereas extranuptial nectar was hexose-rich, had a richer and less variable amino acid chemical profile, with high amounts of serine and alanine amino acids and with higher amounts of the specialized metabolite tyramine. The nectar traits from nuptial and extranuptial nectaries differ in energy amount and nutritional value, as well as in neuroactive specialized metabolites. These differences seem to match floral visitors’ requirements, since they exclusively consume one of the two nectar types and may be exerting selective pressures on the composition of the respective resources of interest.

Made available in DSpace on 2022-04-29T08:34:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The bark (all tissues outside the cambium) is a morphologically diverse and functionally important part of the stem. Outer bark (periderm) has a protective function, and inner bark (secondary phloem) is involved in the long-distance transport. In savannas, the relationship between bark structure, life form and habitat is controversial. We studied the morphology and anatomy of bark of Melastomataceae species with different habits growing at different sites in the Brazilian Cerrado (a neotropical savanna), from well-drained to temporarily or permanently waterlogged soils. Bark samples were processed by standard anatomical techniques. Regarding the outer bark, the species studied are grouped into two main categories: with a single periderm (with nonstratified or stratified phelem) and with multiple periderms, that is, with a rhytidome. Although a formal test has not been carried out in this work to assess the existence of a correlation between the microscopic structure of the periderm and the habit and growth distribution of plants, there seems to be no correlation for most of the species studied here, except for a subshrub species inhabiting waterlogged soils. Sclerified cells, calcium oxalate crystals, and phenolic content are abundant through the secondary phloem. Microscopic bark features are useful to distinguish species. 2021 Departamento de Ciências Biológicas UFES - Universidade Federal Do Espírito Santo Faculdade de Ciências Agronômicas Departamento de Ciência Florestal Solos e Ambiente UNESP - Universidade Estadual Paulista, CP 237 Departamento de Botânica UNESP - Univ Estadual Paulista Instituto de Biociências, CP 510 Faculdade de Ciências Agronômicas Departamento de Ciência Florestal Solos e Ambiente UNESP - Universidade Estadual Paulista, CP 237 Departamento de Botânica UNESP - Univ Estadual Paulista Instituto de Biociências, CP 510

The study combines a range of light and electron microscopy methods to access variation in secretion and ultrastructure in the secretory canals in the above- and belowground stems of Anacardium humile, which here serves as a model system. The aboveground stem canals show epithelial cells with ultrastructural characteristics typical of cells active in secretion, while in the belowground stems, the subcellular characteristics are typical of cells with low rates of metabolism. The secretory canals of the belowground stems show uniformity in size and shape, a large central vacuole, a cytoplasm reduced to a thin layer at the cell periphery, and a reduced population of organelles. The aboveground stem canals had voluminous nuclei with evident nucleoli, a very dense cytoplasm with free ribosomes, polyribosomes, mitochondria with developed cristae, and ellipsoid plastids with electron-opaque droplets surrounded by a periplastid reticulum. The vacuoles were of different sizes and often had membranous contents and the dictyosomes were very developed with dilated ends to the cisternae, rough endoplasmic reticulum, and numerous vesicles. The results show that particularities in above- and belowground environment have significant implications for ultrastructural morphology and functioning of secretory canals in the stems of A. humile.

Made available in DSpace on 2021-06-25T15:01:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Nissolia rondonensis, a new critically endangered species from the state of Rondonia, Brazil, is described and illustrated. Its distribution, informal conservation status, phenology, and morphological and anatomical affinities with its closest relative, Nissolia klugii, are discussed. In addition, a new combination, Nissolia subulata is proposed. A key to the Brazilian species of Nissolia is presented. Sao Paulo State Univ, UNESP, IBB Inst Biosci Botucatu, Dept Bot, POB 510, BR-18618970 Botucatu, SP, Brazil Royal Bot Gardens, Comparat Plant & Fungal Biol Dept, Richmond TW9 3AE, Surrey, England Sao Paulo State Univ, UNESP, Program Postgrad Biol Sci Bot, IBB Inst Biosci Botucatu, BR-18618000 Botucatu, SP, Brazil Inst Fed Goiano, IFG, Urutai Campus, BR-75790000 Urutai, Go, Brazil Missouri Bot Garden, 4344 Shaw Blvd, St Louis, MO 63110 USA Sao Paulo State Univ, UNESP, IBB Inst Biosci Botucatu, Dept Bot, POB 510, BR-18618970 Botucatu, SP, Brazil Sao Paulo State Univ, UNESP, Program Postgrad Biol Sci Bot, IBB Inst Biosci Botucatu, BR-18618000 Botucatu, SP, Brazil CNPq: 400567/2016-4 FAPESP: 2015/13386-0 CAPES: 88887.373155/2019-00 CNPq: 304396/2015-0

Made available in DSpace on 2022-04-29T08:38:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 The legume tree Schizolobium parahyba from the Brazilian Atlantic Forest shows young aerial organs covered with a sticky exudate. Aiming to clarify the functional aspects of the sticky secretions, we performed analyses on the dynamics of secretion through the plant development and characterized the chemical nature of the exudates by histochemical tests. We also studied the secretory tissue using light and electron microscopy. The production of the exudates starts soon after seed germination, being evident in the epicotyl but not in the hypocotyl and cotyledons. The secretory activity extends throughout the juvenile and pre-reproductive phase, in primary stems and leaf portions. After the first flowering, secretion was no longer observed. The lipid exudates are secreted by the epidermis and are composed of mixtures of essential oils and oleoresins. Modified plastids, extensive rough endoplasmic reticulum, proliferated smooth endoplasmic reticulum, enlarged vacuoles containing flocculant materials, membrane debris, and convoluted tubules/lamellae membranes covered with osmiophilic deposits are the main features of the secretory epidermal cells. Secretion exits the protoplast by exocytosis and accumulates in the cuticle, resulting in a sheath of concentric bands of electron-dense deposits, and is released by cuticle peeling. The hydrophobic nature of the secretion, which forms an impermeable layer on the epidermis of young organs, is a relevant attribute of the aerial organs of S. parahyba. In addition to protecting against desiccation, this exudate effectively captures particles and immobilizes insects and other arthropods. Departamento de Botânica Instituto de Ciências Biológicas Universidade Federal de Minas Gerais, Minas Gerais Departamento de Botânica Instituto de Biologia Universidade Federal do Rio de Janeiro Instituto de Biociências de Botucatu Centro de Microscopia Eletrônica Botucatu Universidade Estadual Paulista Instituto de Biociências de Botucatu Centro de Microscopia Eletrônica Botucatu Universidade Estadual Paulista

Made available in DSpace on 2020-12-12T01:40:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Ministério da Ciência e Tecnologia Universidade Estadual Paulista Gelatinous fibers (G-layer) occur widely in various organs and plant tissues of both primary and secondary origin, but they are best known in tension wood. Here, we describe the occurrence, distribution patterns, and structural features of G-fibers in non-woody species of xerophytes and hydrophytes in Brazilian Cerrado (dry soil) and Chaco (wet or periodically waterlogged soils). G-fibers were present in all of the studied species, but were more abundant and more developed in xerophytes. They were associated with the phloem of leaves and primary stems and with the xylem of three xerophytic species that exhibited incipient secondary growth. The G-layer was non-lignified and characterized by greater thickness, lower density, and loose appearance in relation to the secondary layers. Under a transmission electron microscope, G-fibers displayed two secondary parietal layers (S1 and S2) in Prosopis rubriflora Hassle. (xerophyte), three secondary layers (S1, S2, and S3) in Eriosema campestre Benth. var. campestre (xerophyte), and a single secondary layer (S1) in Ludwigia leptocarpa Nutt. (hydrophyte). In P. rubriflora, mature G-fibers exhibited a loose-appearing electron-lucent region (transition zone) between G-and S-layers (secondary layers). In addition to mechanical support, this study suggests the involvement of G-fibers in water storage. Federal University of Mato Grosso do Sul – UFMS Center of Biological and Health Sciences São Paulo State University – UNESP Institute of Biosciences Department of Botany and Centro de Microscopia Eletrônica UNESP – Universidade Estadual Paulista Instituto de Biociências (Campus de Botucatu) Departamento de Botânica, R. Prof. Dr. Antônio Celso Wagner Zanin, 250, Bairro: Distrito de Rubião Junior São Paulo State University – UNESP Institute of Biosciences Department of Botany and Centro de Microscopia Eletrônica UNESP – Universidade Estadual Paulista Instituto de Biociências (Campus de Botucatu) Departamento de Botânica, R. Prof. Dr. Antônio Celso Wagner Zanin, 250, Bairro: Distrito de Rubião Junior CNPq: 02657/ 2011-8 CAPES: 1386382 Ministério da Ciência e Tecnologia: 470649/2008-9

Made available in DSpace on 2020-12-10T19:42:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Reproduction in flowering plants is closely related to the megagametophyte, since the megagametophyte is involved in pollen tube reception and contains the two female gametes-egg cell and central cell. Previous conventional light microscopy methods have shown that female sterility in perfect flowers of Maytenus obtusifolia is associated with the occurrence of sterile ovules whose megagametophytes have hypertrophied synergids. Here, using transmission electron microscopy and cytochemical methods, we compare the megagametophytes in fertile and sterile ovules from perfect and pistillate flowers, and investigate the cellular events that result in the degradation of the megagametophyte cells from sterile ovules. In fertile ovules of perfect and pistillate flowers, mature megagametophytes have two synergids, egg cell and central cell. In fertile ovules, the synergids present an extensive rough endoplasmic reticulum (RER) profile, large populations of mitochondria, when compared to egg cells, vesicles, Golgi bodies, plastids and a nucleus with heterochromatin. Besides that, the egg cell has a small population of organelles and the central cell exhibits cytoplasm with free ribosomes, RER, vesicles originating from the RER, Golgi bodies and oil inclusions. In mature megagametophytes from sterile ovules of perfect and pistillate flowers, massive autophagy occurs by tonoplast rupture promoting hydrolase release, leading to protoplast and cell wall degradation-typical evidence of programmed cell death (PCD). Therefore, female sterility in the majority of M. obtusifolia sterile ovules is the result of PCD by massive autophagy in the megagametophyte cells. In a few other sterile ovules, sterility is due to the delayed or the absence of megagametophyte development. Univ Fed Rio de Janeiro, Museu Nacl, Dept Bot, BR-22940040 Rio De Janeiro, RJ, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Bot, BR-18618000 Sao Paulo, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Bot, BR-18618000 Sao Paulo, SP, Brazil CNPq: 304396/20150 FAPERJ: E-26/111.207/2014 CNPq: 447624/2014-8

Made available in DSpace on 2019-10-06T16:10:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-02-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Although the outer bark is important for protecting the inner tissues of stems of woody plants, especially from fire, the variation of outer bark in environments with different water availability, wind intensities, and solar radiation is little understood. Here, we examined the outer bark structure of Moquiniastrum polymorphum (Asteraceae) and Zanthoxylum rhoifolium (Rutaceae), co-occurring species in cerrado sensu stricto, cerradão, semi-deciduous seasonal forest and rainforest. Cerrado sensu stricto is a savanna with relatively intense solar radiation and winds. Cerradão, semi-deciduous seasonal forest and rainforest are progressively more closed and humid. We tested if trees in cerrado sensu stricto have relatively thicker outer and total bark than trees in the other three environments. For individuals of each species from each habitat, we described the morphological and anatomical features of the outer bark, including the origin of the first periderm. We compared the relative thickness of outer and total bark among habitats by means of ANOVA. In both species, we observed no qualitative differences in the morphological and anatomical features of the outer bark; therefore, these features are diagnostic for each species. For all habitats, the deep-seated origin of the first periderm and formation of a rhytidome in M. polymorphum produce a grooved bark with a loose appearance, whereas the subepidermal origin and formation of a single periderm in Z. rhoifolium produce a more uniform and smooth-appearing bark. Zanthoxylum rhoifolium trees in cerrado sensu stricto and cerradão have a thinner periderm, whereas M. polymorphum trees do not vary in rhytidome thickness among the habitats. In summary, trees from cerrado sensu stricto did not have relatively thicker outer bark and total bark than trees in cerradão, semi-deciduous seasonal forest and rainforest, suggesting that seasonal drought, intense solar radiation and winds do not seem to affect the total thickness of the outer bark. UNESP - São Paulo State University Faculdade de Ciências Agronômicas Departamento de Ciência Florestal Laboratório de Anatomia da Madeira, Avenida Universitária, 3780 UNESP - São Paulo State University Instituto de Biociências de Botucatu Departamento de Botânica, Distrito de Rubião Junior UNESP - São Paulo State University Faculdade de Ciências Agronômicas Departamento de Ciência Florestal Laboratório de Anatomia da Madeira, Avenida Universitária, 3780 UNESP - São Paulo State University Instituto de Biociências de Botucatu Departamento de Botânica, Distrito de Rubião Junior FAPESP: 2015/14954-1 CNPq: 304396/2015-0

Made available in DSpace on 2021-06-25T11:13:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Regrowth via production of epicormic shoots is an important strategy for many woody plants after environmental disturbances such as fire, drought, and herbivory. Populations spreading across a broad latitudinal gradient offer opportunities to investigate if essential traits vary with heterogenous environmental conditions, such as in savanna ecosystems. This information can help us predict plant responses to climate change. Here, we evaluated if epicormic bud protection traits varied among populations of three focal savanna species (Miconia albicans, Solanum lycocarpum, and Zeyheria montana) that have a wide distribution and grow under variable climatic conditions. We randomly sampled 225 individuals over five spatially independent sites (7°, 10°, 15°, 18°, and 24° S) in Brazil, totaling 15 individuals per species per area. We analyzed anatomical transverse sections of five buds per species per area to assess the relative area occupied by crystal and phenolic idioblasts, the thickness of the trichome boundary layer, and to test if these traits were associated with climatic conditions. The buds were protected by cataphylls and composed of a variable number of undeveloped leaves enveloping the shoot apex. For M. albicans, we found an association between maximum temperature and both phenolic idioblasts and trichome boundary layer, but no association with crystal idioblasts. In S. lycocarpum, only the trichome boundary layer was associated with maximum temperature plus high radiation. Z. montana showed no variation. Combination of two or more traits can lead to the development of adaptative strategies to different climatic conditions. We present for the first time an analysis of epicormic bud traits in plant populations occurring in an extensive latitudinal gradient and shed light on how maximum temperature is associated with these traits, contributing to a better understanding of plant resprouting capabilities in widespread savanna plant species. Graduate Program in Biological Sciences (Botany) Institute of Biosciences UNESP – São Paulo State University, Rua Prof. Dr. Antonio Celso Wagner Zanin, s/n 18618-689 Laboratory of Ecology and Evolution of Plant-Animal Interactions Institute of Biosciences São Paulo State University Laboratory of Plant Anatomy Institute of Biosciences São Paulo State University Graduate Program in Biological Sciences (Botany) Institute of Biosciences UNESP – São Paulo State University, Rua Prof. Dr. Antonio Celso Wagner Zanin, s/n 18618-689 Laboratory of Ecology and Evolution of Plant-Animal Interactions Institute of Biosciences São Paulo State University Laboratory of Plant Anatomy Institute of Biosciences São Paulo State University

Made available in DSpace on 2021-06-25T10:37:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The neem tree (Azadirachta indica A.Juss.) contains a range of biologically active compounds—mainly triterpenoids produced in single secretory cells, which are distributed among all plant parts. Neem secretions are toxic to animal cells, triggering autolytic mechanisms that culminate in cell disruption. However, little is known about the self-toxicity of these secretions to the cells that produce them. We carried out an anatomical, histochemical, and ultrastructural investigation of neem’s single secretory cells in the shoot apex and in young leaves. We evaluated the morphological changes as possible evidences of stress reactions to their own secretions. The subcellular apparatus involved in synthesis and compartmentation was consistent with hydrophilic and lipophilic secretions. Polymorphic plastids devoid of thylakoids and abundant smooth endoplasmic reticulum in the later stages of differentiation are comparable with previous reports on neem cotyledons with regard to terpenoid synthesis. However, secretions were compartmentalized within autophagic vacuoles and periplasmic spaces instead of in terpenoid vesicles. Cellular swelling, increased vesiculation, dilatation of endoplasmic reticulum cisternae, mitochondrial hypertrophy in the cristolysis process, autolytic vacuoles, and vacuolar degeneration culminating in protoplast autolysis are all consistent with early indications of autotoxicity. The signaling stress reaction mechanism was expressed as cytoplasmic deposits of calcium salt and by the expression of a 70-kDa heat-shock protein. The morphological and histochemical changes in the secreting cells are comparable with those described in animal cells exposed to neem oil. Our data provide evidence of cell damage and signaling reactions linked to these cells’ own secretions before autolysis. IBB - Institute of Biosciences of Botucatu Laboratory of Plant Anatomy UNESP - São Paulo State University, PO Box 510 IBB - Institute of Biosciences of Botucatu Laboratory of Insects UNESP - São Paulo State University, PO Box 510 IBB - Institute of Biosciences of Botucatu Laboratory of Plant Anatomy UNESP - São Paulo State University, PO Box 510 IBB - Institute of Biosciences of Botucatu Laboratory of Insects UNESP - São Paulo State University, PO Box 510 CNPq: 304396/2015-0 CNPq: 401053/2016-4

Made available in DSpace on 2020-12-12T02:43:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The oily resin produced by Copaifera langsdorffii, commonly called oil of copaiba, is widely exploited by the drug, cosmetic, and biodiesel industries. The distribution of oily secretory cavities and canals (secretory spaces) over the vegetative body characterizes this species. Oil is stored inside the lumen of the secretory spaces and only reaches the organ surface after injuries. Nonetheless, translucent oily deposits occur on the adaxial surface of intact young leaves. In this study, we searched for further sources of oil production in C. langsdorffii leaves in addition to the well-known secretory cavities and investigated the mechanisms of secretion. Leaves in different developmental stages were collected from adult plants and processed for studies on light and transmission electron microscopies. The primary finding of this study was the involvement of the chlorenchyma cells in lipid biosynthesis, in addition to the secretory cavities. The secretory activity of cavities and chlorenchyma cells overlapped in young leaves. Ultrastructurally, secretory cavity cells exhibited abundant smooth endoplasmic reticulum profiles and oleoplasts, whereas the chlorenchyma cells had large chloroplasts with oil inclusions. Our data suggest that the oily material on the leaf surface arose from the chlorenchyma and was transported via the apoplast. These findings open new avenues for understanding oil biosynthesis regulation in mesophyll cells and planning of future strategies for the biotechnological application of C. langsdorffii leaves. Graduate Program in Biological Sciences (Botany) Institute of Biosciences São Paulo State University (UNESP) Goiás State University (UEG) Department of Botany Institute of Biosciences São Paulo State University (UNESP) Graduate Program in Biological Sciences (Botany) Institute of Biosciences São Paulo State University (UNESP) Department of Botany Institute of Biosciences São Paulo State University (UNESP) CAPES: 001 CNPq: 02657/2011-8 FAPESP: 2008/55434-7 CNPq: 303981/2018-0

Made available in DSpace on 2020-12-12T02:08:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 G-fibers have been widely studied in tension wood, but few studies are available on aerial and underground organs of shrub and subshrub, specially comparing those organs of the same plant. The goal of this study is to compare the general pattern of G-fibers distribution, and the structure and histochemistry of G-fibers walls between aerial and underground organs in 19 Eriosema taxa occurring in the tropical savanna, locally called cerrado. The samples were processed according to standard techniques in plant anatomy and histochemistry. G-fibers occurred throughout the vegetative body and were exclusively extraxylary in organs with primary growth and extraxylary and xylary in organs with incipient secondary growth. G-fibers were more abundant and had a thicker G-layer in the underground organs. In all the organs analyzed, the G-fibers were identified by the presence of a non-lignified internal translucent layer (G-layer) sometimes occupying the entire lumen of the fiber. The abundance and wide occurrence of G-fibers in the vegetative axis of Eriosema plants may represent an adaptive mechanism and may explain why plants that belong to this genus are able to survive in adverse Cerrado conditions. We suggest that the conditions of the Cerrado environment may stimulate the differentiation of gelatinous fibers in these plants. In addition, the ecophysiological significance of the G-fibers, we emphasize their taxonomic value as a unifying character of the Eriosema genus. UNESP – São Paulo State University IBB – Institute of Biosciences of Botucatu Postgraduate Program in Biological Sciences (Botany) UNESP – São Paulo State University IBB – Institute of Biosciences of Botucatu Department of Botany, PO Box 510 UNESP – São Paulo State University IBB – Institute of Biosciences of Botucatu Postgraduate Program in Biological Sciences (Botany) UNESP – São Paulo State University IBB – Institute of Biosciences of Botucatu Department of Botany, PO Box 510

Made available in DSpace on 2020-12-12T02:37:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Floral fragrances play an important role in pollinator attraction; they serve as signals for primary rewards such as nectar. The presence of osmophores (a specialized glandular tissue that produces fragrance) in the terrestrial orchid Cyclopogon has only been described in a single species. There are fragrant and odorless species within this genus, but no data on the similarities or differences between them has been published. Here, we present new data on the lip morphology and ultrastructure from eight Cyclopogon species to better understand the mechanisms of pollinator attraction of this group. To achieve this goal, we used light, scanning, and transmission electron microscopy. Five out of eight species presented globular trichomes associated with fragrance production on the abaxial side of the labellum. Together with subepidermal cells, they compose the secretory tissue. Despite the absence of globular trichomes, C. apricus also presented cells associated with fragrance production. Lipid droplets, plastids containing plastoglobuli, and starch were indicators of secretory activity present in these species. This same pattern of fragrance production and release, associated with flower morphology, may result in the restriction of pollination by halictid bees. Institute of Biosciences Department of Botany São Paulo State University – UNESP Institute of Biosciences Department of Botany São Paulo State University – UNESP CNPq: 304396/2015-0 CAPES: 88882.317776/2019-01

Made available in DSpace on 2019-10-04T12:37:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Perfect flowers of Maytenus obtusifolia have partial sterility of pollen grains, resulting in collapsed and developed free microspores. However, the cellular events resulting in partial male sterility have not been determined. In pistillate flowers of this species, male sterility is related to the premature programmed cell death (PCD) in tapetum and sporogenic cells. The process occurs through autophagy via macroautophagy and massive autophagy and is associated with sporophytic cytoplasmic male sterility (CMS). Here, we characterised the development of pollen grains and investigated the cellular events that result in tapetum cells and free microspores PCD in perfect flowers, using light and transmission electron microscopy combined with the TUNEL (Terminal deoxynucleotidyl transferase mediated dUDP end-Labeling) assay and the ZIO (Zinc iodide-osmium tetroxide) method. Pollen grain development in perfect flowers was divided into eight developmental stages based on the characteristics of the pollen grains. Tapetum cells undergo PCD at the free microspore stage, through a macroautophagic process, by formation of autophagosomes and by autophagosomes giving rise to lytic vacuoles at maturity. In the final stage of PCD, massive autophagy occurs by rupture of the tonoplast. The development of viable and inviable microspores diverges at the vacuolated microspore stage, when PCD occurs in some free microspores, causing interruption of pollen development through necrosis. These events result in the observed partial male sterility. Viable microspores undergo mitosis and develop into tricellular pollen grains. Male sterility in hermaphrodite individuals is here interpreted as gametophytic CMS. Univ Fed Rio de Janeiro, Dept Bot, Museu Nacl, BR-22940040 Rio De Janeiro, RJ, Brazil Univ Estadual Paulista, Dept Bot, Inst Biociencias, BR-18618000 Botucatu, SP, Brazil Univ Estadual Paulista, Dept Bot, Inst Biociencias, BR-18618000 Botucatu, SP, Brazil FAPERJ: E-26/111.207/2014 CNPq: 447624/2014-8 CNPq: 304396/2015-0

Made available in DSpace on 2019-10-04T12:36:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-03-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The subtribe Cajaninae of papilionoid legumes has a pantropical distribution and comprises approximately 490 species. These species have diversified throughout dry environments where there are high temperatures and strong light. The subtribe stands out because all its representatives have vesicular glands. In addition, bulbous-based and capitate trichomes are important secretory structures present in all genera of the Cajaninae. We analyzed the ultrastructure and histochemistry of these glandular trichome types in leaflets of the three species of the subtribe. Using transmission electron microscopy and histochemical analyses, we link the glandular secretions to subcellular structures. We here report for the first time the type of exudate and ultrastructure of the glands of subtribe Cajaninae. Terpenoids and phenolics were confirmed by histochemistry tests, and we observed that the organelles responsible for biosynthesis of oils are the most representative in these glands. Each glandular trichome showed particular ultrastructural features compatible with the compounds produced. We suggest that these glandular trichomes, with their respective exudates, act in defense against herbivory and against possible damage by ultraviolet radiation. Univ Estadual Paulista, Inst Biociencias, Programa Posgrad Ciencias Biol Bot, Dept Bot,Inst Biociencias, BR-18618000 Botucatu, SP, Brazil Univ Estadual Campinas, Inst Biol, Dept Biol Vegetal, Programa Posgrad Biol Vegetal, BR-13083862 Campinas, SP, Brazil Royal Bot Gardens, Comparat Plant & Fungal Biol Dept, Richmond TW9 3AB, Surrey, England Smithsonian Inst, NMNH, Dept Bot, US Natl Herbarium US, MRC 166,10th & Constitut Ave, Washington, DC 20560 USA Univ Copenhagen, Dept Geosci & Nat Resource Management, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark Univ Estadual Paulista, Inst Biociencias, Programa Posgrad Ciencias Biol Bot, Dept Bot,Inst Biociencias, BR-18618000 Botucatu, SP, Brazil FAPESP: 2015/13386-0 CNPq: 457911/2013-1 CNPq: 400567/2016-4 CNPq: 304396/2015-0 CNPq: 140598/2015-4

Made available in DSpace on 2018-12-11T17:37:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-07-11 The cellular mechanisms of laticifer growth are of particular interest in plant biology but are commonly neglected. Using transmission electron microscopy and immunocytochemical methods, we recorded cytological differentiation and evaluated the cell wall involvement in the growth of articulated laticifers with intrusive growth in the mature embryo and plant shoot apex of Tabernaemontana catharinensis. The incorporation of adjacent meristematic cells into the laticifer system occurred in the embryo and plant shoot apex, and the incorporated cells acquired features of laticifer, confirming the laticifers’ action-inducing mechanism. In the embryo, this was the main growth mechanism, and began with enlargement of the plasmodesmata and the formation of pores between laticifers and meristematic cells. In the plant shoot apex, it began with loose and disassembled walls and the reorientation of the cortical microtubules of the incorporated cell. Plasmodesmata were absent in these laticifers. There was stronger evidence of intrusive growth in undifferentiated portions of the plant shoot apex than in the embryo. The numerous plasmodesmata in laticifers of the embryo may have been related to the lower frequency of intrusive growth. Intrusive growth was associated with presence of arabinan (increasing wall flexibility and fluidity), and absence of galactan (avoiding wall stiffness), and callose (as a consequence of reduction in symplastic connections) in the laticifer walls. The abundance of low de-methyl-esterified homogalacturonan in the middle lamella and corners may reestablish cell-cell bonding in the laticifers. The cell wall features differed between embryo and plant shoot apex and are directly associated to laticifer growth mechanisms. Department of Botany Institute of Biosciences Universidade Estadual Paulista – UNESP Laboratory of Plant Anatomy Department of Botany Universidade Federal do Rio Grande do Sul Department of Botany Institute of Biosciences Universidade Estadual Paulista – UNESP

Made available in DSpace on 2018-12-11T17:16:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Plant species have been classified as being either heterobaric or homobaric based on the presence or absence (respectively) of bundle sheath extensions (BSE) in leaf veins. These leaf types differ in their physiological performance, and their occurrences tend to be associated with environment. This study investigated the presence/absence of BSE and their structural peculiarities in 49 woody species (28 angiosperm families) in the Brazilian Cerrado using anatomical methods. We measured the gas exchange indices and stomatal density. In addition to typical homobaric (61.2%) and heterobaric (22.4%) species, we also found species with intermediate BSE features. These we call “larger heterobaric” (12.2%) and “semi-heterobaric” (4.1%) species. In the former, BSE occurs around only the secondary veins, whereas in the latter the BSE projects only towards the adaxial leaf surface. The net CO2 assimilation rates, the stomatal conductance, the transpiration rates, and the carboxylation efficiencies were statistically higher in heterobaric than in homobaric species. In the larger heterobaric species, the photosynthetic indices were similar to those in the heterobaric species. Meanwhile, semi-heterobaric species showed photosynthetic indices similar to the homobaric species. We demonstrated that structural variation in the BSE is linked to physiological leaf performance, suggesting some correlation between leaf morphology and plant adaptations. São Paulo State University (UNESP) Institute of Biosciences of Botucatu (IBB) Centro de Microscopia Eletrônica (CME) São Paulo State University (UNESP) Institute of Biosciences of Botucatu (IBB) São Paulo State University (UNESP) Institute of Biosciences of Botucatu (IBB) Centro de Microscopia Eletrônica (CME) São Paulo State University (UNESP) Institute of Biosciences of Botucatu (IBB) FAPESP: 2014/12482-2 FAPESP: 2015/16307-3

Made available in DSpace on 2018-12-11T17:15:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-10-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Abscisic acid (ABA) attenuates stomatal conductance (gs) and transpiration (E) in response to drought. Broadly known as ‘Brazilian savanna’, the Cerrado sensu lato is a mosaic of landscapes, including savanna-type vegetation, such as the cerrado sensu stricto (s. str.), and riparian forests occurring along rivers. These habitats share floristic elements, and congeneric species are adapted to grow in these drought- and flood-prone environments. We assessed leaf concentration of ABA and its metabolites, as well as gs, E and leaf water potential (Ψw) in shrubs of Styrax ferrugineus in a cerrado s. str. (savanna species) and in trees of S. pohlii in a riparian forest (forest species), in both the wet and dry seasons. We also quantified 9-cis epoxycarotenoid dioxygenase (NCED) gene expression in leaves, and wood anatomical features in stems. We expected that the forest species would not increase their leaf ABA content during the dry season because of the moist soil from the riparian forest. Regardless of the environment, both species expressed NCED, synthesized ABA, and exhibited reductions in both Ψw and gs in the dry season, confirming these as universal responses to the dry season. The savanna species had more xylem vessels per mm2 and these vessels were narrower than those observed in stems of the forest species, resulting in a low vulnerability to cavitation (lvul) estimated for both species. Our results demonstrate that, despite inhabiting contrasting habitats, these species display similar ecophysiological responses to the dry season and their wood anatomical features may explain their geographical distribution. Programa de Pós-Graduação em Ciências Biológicas (Biologia Vegetal) Universidade Estadual Paulista UNESP Instituto de Biociências Departamento de Botânica, Av. 24-A, 1515 Centro de P&D de Sanidade Vegetal Laboratório de Bioquímica Fitopatológica Instituto Biológico, Av. Conselheiro R. Alves, 1252 Instituto de Ciências Biológicas Universidade de Brasília UnB, Campus Universitário Darcy Ribeiro, Asa Norte Departamento de Ciência Florestal Universidade Estadual Paulista UNESP Faculdade de Ciências Agronômicas, C.P. 237 Departamento de Botânica Universidade Estadual Paulista UNESP Instituto de Biociências, C.P. 510 Department of Plant Biology Institute of Biology University of Campinas – UNICAMP, P.O. Box: 6109 Departamento de Botânica Universidade Estadual Paulista UNESP Instituto de Biociências, Av. 24-A, 1515 Programa de Pós-Graduação em Ciências Biológicas (Biologia Vegetal) Universidade Estadual Paulista UNESP Instituto de Biociências Departamento de Botânica, Av. 24-A, 1515 Departamento de Ciência Florestal Universidade Estadual Paulista UNESP Faculdade de Ciências Agronômicas, C.P. 237 Departamento de Botânica Universidade Estadual Paulista UNESP Instituto de Biociências, C.P. 510 Departamento de Botânica Universidade Estadual Paulista UNESP Instituto de Biociências, Av. 24-A, 1515 FAPESP: 2009/54208-6 CNPq: 471452/2008-4

Made available in DSpace on 2018-12-11T17:11:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Family Melastomataceae is an important component of the Brazilian Cerrado flora, inhabiting different environments from those with well-drained soils to swamp soil sites. Several members of this family are recognized as aluminum (Al)-accumulating. We studied the wood anatomy of six species of Melastomataceae (Miconia albicans (Sw.) Triana, M. fallax DC., M. chamissois Naudin, M. ligustroides (DC.) Naudin, Microlepis oleaefolia (DC.) Triana, Rhynchanthera dichotoma DC.), growing in different environments of Cerrado, exploring the occurrence of trabeculae and Al-accumulation sites. We processed the material following the usual techniques in wood anatomy and histochemistry.Weused a chrome azurol-S spot-test in fresh material to detect Al-accumulation. The common features were diffuse porosity, vessel elements with simple perforation plates and vestured pits, abundant parenchyma-like fiber bands and septate fibers, axial parenchyma scanty to vasicentric, and heterocellular rays. The presence of trabeculae in vessel elements, septa in parenchyma cells, and aluminum in the G-layer of the gelatinous fiber walls, in the septa of fibers, in cambial initials and derivatives cell walls, and in the vacuole of ray cells are recorded for the first time for Melastomataceae. The results of this study indicate an additional role for gelatinous fibers in Al-accumulation, and offer a new perspective on Al-compartmentalization in the wood cells from Cerrado species. UFES-Universidade Federal do Espírito Santo Departamento de Ciências Biológicas UNESP-Universidade Estadual Paulista Faculdade de Ciências Agronômicas Departamento de Ciência Florestal, CP 237 UNESP-Universidade Estadual Paulista Instituto de Biociências Departamento de Botânica, CP 510 UNESP-Universidade Estadual Paulista Faculdade de Ciências Agronômicas Departamento de Ciência Florestal, CP 237 UNESP-Universidade Estadual Paulista Instituto de Biociências Departamento de Botânica, CP 510 FAPESP: 00/12469-3 FAPESP: 03/00958-8 FAPESP: 15/14954-1 CNPq: 301464/2008-1

Made available in DSpace on 2018-12-11T17:30:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-02-01 Zeyheria tuberculosa, a Bignoniaceae tree that occurs in a broad latitudinal range in Brazilian forests, is a threatened species of seasonal tropical forest. It is crucial to enhance the knowledge on this species’ floral biology, since interactions related to reproduction of plants are critical for the long term maintenance of their populations. Thus, we investigated the sexual reproduction and floral biology of Z. tuberculosa, including nectar features, aiming to understand the ecological processes associated to this mutualistic plant-animal interaction in the current modified landscape. For this, we performed experiments under natural conditions and in the laboratory. All the evaluated plants were self-incompatible. Zeyheria tuberculosa was pollinated by Bombus pauloensis, a medium-sized bee, and offered hexose-rich nectar as resource. Flowers were also visited by small-sized bee species, Trigona spinipes, that acted as pollen thief, and Pseudoaugochlora pandora and P. graminae that acted as nectar thieves. These three bee groups exhibited temporal separation in the peak of visits throughout the day. The peak of pollinator visits occurred firstly, which may allow the pollinator to access nectar and pollen loads before they are exploited by thieves. However, bee pollinator visits were scarce, and this fact, associated to the self-incompatibility of Z. tuberculosa, may explain the low fruit set registered in the studied plants. It could be of special concern for this threatened species maintenance in the medium and long term, which depends on the offspring originated by sexual reproduction. Graduation Program in Biological Sciences (Botany) São Paulo State University (Unesp) Institute of Biosciences, Caixa Postal 510 Department of Life Sciences University of Siena, Via P. A. Mattioli 4 Department of Botany São Paulo State University (Unesp) Institute of Biosciences, Caixa Postal 510 Graduation Program in Biological Sciences (Botany) São Paulo State University (Unesp) Institute of Biosciences, Caixa Postal 510 Department of Botany São Paulo State University (Unesp) Institute of Biosciences, Caixa Postal 510

Made available in DSpace on 2020-12-12T02:47:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Cactaceae exhibit highly modified spines that are considered to be extrafloral nectaries (EFNs). Despite their ecological and taxonomical relevance in this family, little is known on their structure and function. We have described the anatomy, ontogenesis, and ultrastructure of the secretory glochids in two Opuntioideae species. Young cladodes of Brasiliopuntia brasiliensis (Willd.) A. Berger and Nopalea cochenillifera (L.) Salm-Dyck were processed for light and electron microscopy studies. The composition of the secretions was analyzed by high performance liquid chromatography. The secretory glochids were soft, massive, and barbed, as well as translucent. Hyaline droplets on the secretory glochid apex were collected by aggressive ants. The secretory glochids originated from the areolar meristem, beginning as small protuberances formed by protoderm and ground meristem. Mature secretory glochids consisted of a central multiseriate axis of ground cells covered by uniseriate epidermis with a continuous cuticle, and exhibited three regions: (i) dilated vascularized base with parenchyma cells exhibiting features associated to nectar secretion; (ii) elongated median region with juxtaposed fusiform non-lignified parenchyma cells; and (iii) tapered apical portion with immature fibers loosely arranged cells. The exudate was sucrose-dominant with a similar amino acid profile in both species. Our results shed light on the secretory activity of glochids in Cactaceae and their role in cactus–ant interactions. UNESP – São Paulo State University Institute of Biosciences Department of Botany University of Siena Department of Life Sciences UNESP – São Paulo State University Institute of Biosciences Department of Botany CAPES: 001 FAPESP: 2017 / 14891-5 CNPq: 303981/ 2018-0 CNPq: 304396/2015-0

Made available in DSpace on 2019-10-06T16:31:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-08-01 Main conclusion: Different autophagy pathways are a driver of vacuolar biogenesis and are development stage specific during the extrafloral nectary development in Citharexylum myrianthum. Abstract: Plant autophagy plays an important role in various developmental processes such as seed germination, pollen maturation and leaf senescence. However, studies that address the evidence of autophagy and its role in the development of plant glands are scarce and largely restricted to laticifers. Regarding nectary, studies have repeatedly pointed to signs of degradation associated with the end of the secretory cycle, without exploring autophagy. Likewise, the relationship between autophagy and biogenesis of vacuoles remains an unexplored issue. In this study, using conventional and microwave fixation in association with ultracytochemical methods for transmission electron microscopy, we investigated the occurrence of autophagy and its implication in the differentiation of extrafloral nectary in Citharexylum myrianthum (Verbenaceae) under natural conditions, focusing on the vacuole biogenesis. We described a variety of vacuole types associated with the stage of nectary epidermis development, which differs with respect to origin, function and nature of the products to be stored. Three distinct autophagy pathways were detected: macroautophagy, microautophagy (both restricted to the undifferentiated epidermal cells, at the presecretory stage) and megaautophagy (circumscribed to the differentiated epidermal cells, at the postsecretory stage). Our study clearly demonstrated that the vacuole variety and autophagy processes in the nectary epidermal cells are development specific. This study highlights the role of autophagy in vacuole biogenesis and its implications for the development of nectary and opens new venues for future studies on regulation mechanisms for autophagy in plant secretory structures under normal conditions. Department of Botany Institute of Biosciences of Botucatu (IBB) São Paulo State University (UNESP) Center of Electron Microscopy (CME) Institute of Biosciences of Botucatu (IBB) São Paulo State University (UNESP) Department of Botany Institute of Biosciences of Botucatu (IBB) São Paulo State University (UNESP) Center of Electron Microscopy (CME) Institute of Biosciences of Botucatu (IBB) São Paulo State University (UNESP)

Made available in DSpace on 2021-06-25T11:17:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Subcellular features of glandular trichomes have been extensively studied in plants of a variety of families, but the role that the cytoskeleton plays in gland morphology and functioning has been neglected. We investigated morphological and subcellular alterations in glandular trichomes of two species of Lamiaceae submitted to cytoskeletal polymerization-inhibiting drugs and low levels of Ca2+, a known modulator of cytoskeleton activity. Plants of Hyptis villosa and Ocimum gratissimum were submitted to Oryzalin and Cytochalasin D and 240 mgL−1, 160 mgL−1, 80 mgL−1, 40 mgL−1 and 0 mgL−1 of Ca2+. Samples were analyzed using scanning and transmission electron microscopy. Both cytoskeleton destabilizing drugs and low levels of Ca2+ led to morphological alterations of the wall structure of glandular head cells in both species, in addition to cytoplasm and organelle degradation. The results showed that cytoskeletal polymerization-inhibiting drugs and low levels of Ca2+ cause similar structural alterations in glandular trichomes which can lead to problems mainly concerning secretion release. New studies involving molecular approaches must be conducted to elucidate the role of cytoskeletal elements during the morphogenesis and functioning of glandular trichomes. UNESP - São Paulo State University Institute of Biosciences Department of Botany UFRRJ - Federal Rural University of Rio de Janeiro Institute of Biological and Health Sciences Department of Botany, BR-465 Road, Km 7, Zip Code 23897-000, P.O. Box: 549 UNESP - São Paulo State University Institute of Biosciences Department of Botany

Made available in DSpace on 2018-12-11T17:08:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-07-01 This study investigates the histology and subcellular features of secretory cavities during the development of the shoot apex of Metrodorea nigra A. St.-Hil. in order to better understand the functioning of these glands. This Rutaceae species is a very suitable model for studying secretory cavity life span, since the shoot apex exhibits both dormant and growth stages during its annual cycle. Shoot apices were collected during the dormant and growth stages from populations of M. nigra growing under natural conditions. Materials were processed using standard techniques for light and electron microscopy. The secretory cavities originate under the protodermis, and their initiation is restricted to the early developmental stage of shoot organs, which are protected by a hood-shaped structure. Secretory cavities have a multi-seriate epithelium surrounding a lumen that expands schizolysigenously. Oil production begins before lumen formation. When the shoot apex resumes development after the dormant stage, the glands remain active in oil secretion in the developing shoot apex and fully expanded leaves. The mature epithelial cells are flattened and exhibit very thin walls, large oil bodies, leucoplasts surrounded by endoplasmic reticulum, and mitochondria with unusual morphology. The tangential walls of the epithelial cells facing the lumen undergo continuous peeling. The vacuole extrusion appears to be the primary mode of release oil into the lumen, in an exocytotic way. The continuity of oil secretion is ensured by the replacement of the damaged inner epithelial cells by divisions in the parenchyma layer that surround the oil gland, likely a meristematic sheath. Departamento de Botânica Instituto de Biociências de Botucatu University Estadual Paulista UNESP Departamento de Botânica Instituto de Biociências de Botucatu University Estadual Paulista UNESP

Made available in DSpace on 2018-12-11T17:02:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-08-01 Seasonal cambial activity was investigated in one- to three-year-old branch modules (branch constructional units) of ten woody species from cerrado sensu stricto, a savanna-like ecosystem, of southern Brazil. Relationships between cambial activity and environmental factors (precipitation, temperature, day length) and leaf production were tested using generalized linear mixed model. Regardless the plant habit and leaf shedding patterns, cambial activity (about 5 months) corresponded to the core of the rainy season (when at least 66% of the annual precipitation had been reached), even though there was some delay or advance in the timing of cambial activity depending on the branch age or species. Cambial activity began in the dry season and ceased before the end of rainy season. Although cambial activity has been positively correlated with day length, precipitation, temperature, and budding for all species, day length, among the assessed factors, seems to be the best predictor of onset and cessation of cambial activity in the branch modules of cerrado species. Univ Estadual Paulista-UNESP Faculdade de Ciências Agronômicas Departamento de Ciência Florestal, Rua José Barbosa de Barros, n 1780 Univ Estadual Paulista-UNESP Instituto de Biociências Departamento de Botânica UNICAMP UNESP USDA Forest Products Laboratory Center for Wood Anatomy Research, One Gifford Pinchot Dr Univ Estadual Paulista-UNESP Faculdade de Ciências Agronômicas Departamento de Ciência Florestal, Rua José Barbosa de Barros, n 1780 Univ Estadual Paulista-UNESP Instituto de Biociências Departamento de Botânica UNESP

Made available in DSpace on 2018-12-11T17:02:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-08-01 Avicennia schaueriana, Laguncularia racemosa and Rhizophora mangle were experimentally exposed to increasing levels of iron (0, 10, 20 and 100 mg L-1 added Fe(II) in Hoagland's nutritive medium). The uptake and translocation of iron from roots to stems and leaves, Fe-secretion through salt glands (Avicennia schaueriana and Laguncularia racemosa) as well as anatomical and histochemical changes in plant tissues were evaluated. The main goal of this work was to assess the diverse capacity of these plants to detect mangroves at risk in an area affected by iron pollution (Vitoria, Espírito Santo, Brazil). Results show that plants have differential patterns with respect to bioaccumulation, translocation and secretion of iron through salt glands. L. racemosa showed the best environmental sensing capacity since the bioaccumulation of iron in both Fe-plaque and roots was higher and increased as the amount of added-iron rose. Fewer changes in translocation factors throughout increasing added-iron were observed in this species. Furthermore, the amount of iron secreted through salt glands of L. racemosa was strongly inhibited when exposed to added-iron. Among three studied species, A. schaueriana showed the highest levels of iron in stems and leaves. On the other hand, Rhizophora mangle presented low values of iron in these compartments. Even so, there was a significant drop in the translocation factor between aerial parts with respect to roots, since the bioaccumulation in plaque and roots of R. mangle increased as iron concentration rose. Moreover, rhizophores of R. mangle did not show changes in bioaccumulation throughout the studied concentrations. So far, we propose L. racemosa as the best species for monitoring iron pollution in affected mangroves areas. To our knowledge, this is the first detailed report on the response of these plants to increasing iron concentration under controlled conditions, complementing existing data on the behavior of the same plants under field exposure. Universidade Estadual Paulista Júlio de Mesquita Filho-UNESP Instituto de Biociências de Botucatu Departamento de Botânica, P.O. Box 510 Universidade Federal Do Espírito Santo Centro de Ciências Humanas e Naturais Departamento de Ciências Biológicas Universidade Federal de São Carlos Centro de Ciências Biológicas e da Saúde Departamento de Ciências Fisiológicas ICYTAC Instituto de Ciencia y Tecnología de Alimentos Córdoba CONICET Dpto. Qca. Orgánica Fac. Cs. Químicas Universidad Nacional de Córdoba Ciudad Universitaria Universidade Estadual Paulista Júlio de Mesquita Filho-UNESP Instituto de Biociências de Botucatu Departamento de Botânica, P.O. Box 510

Made available in DSpace on 2018-11-26T16:32:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Many Velloziaceae flowers present conspicuous glands, whose taxonomic value has already been highlighted. However, until now, their micromorphology, anatomy and ultrastructure have not been investigated, nor have the natures and possible functions of their exudates. Our aim was to investigate distribution, ontogenesis, structure, and secretion mechanisms of glands of Barbacenia flava and Vellozia intermedia and to discuss their possible ecological functions. Samples were prepared according to standard methods for investigations of plant anatomy, scanning electron microscopy, and transmission electron microscopy. Histochemical tests were performed, and focal field observations were made in the study site. The capitate stalked glands on the pedicel, tepals and hypanthium are covered by a sticky secretion that is released in the gland head through the outer periclinal cell walls and cuticle. Secretions are produced in the epidermal and subepidermal cells that contain structural components typical of mixed, mainly lipophilic secretions. Bacteria were found inside the oil-resin gland cells of both species. The Meliponina bees Trigona spinipes and Tetragonisca angustula were observed collecting resin from both species, but were not involved in pollination. Our observations clearly indicate that flower glands of B. flava and V. intermedia are oil-resin secreting and remain active in secretion from very young buds, through to immature fruit. New, smaller glands replace senescent glands by divisions near the base of the original stalk cells. Oil-resin glands have a number of different, but important functions, including the interaction with Meliponina bees, protection against water loss and high temperatures by ultraviolet screening, and anti-desiccant properties. Univ Fed Rio de Janeiro, Museu Nacl, Dept Bot, BR-22940040 Rio De Janeiro, RJ, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Bot, Caixa Postal 510, BR-18618000 Botucatu, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Bot, Caixa Postal 510, BR-18618000 Botucatu, SP, Brazil FAPERJ: E-26/111.207/2014 CNPq: 447624/2014-8

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Made available in DSpace on 2018-11-26T17:55:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-05 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) National Council of Technological and Scientific Development The presence of nectarless flowers in nectariferous plants is a widespread phenomenon in angiosperms. However, the frequency and distribution of nectarless flowers in natural populations, and the transition from nectariferous to nectarless flowers are poorly known. Variation in nectar production may affect mutualism stability, since energetic resource availability influences pollinators' foraging behavior. Here, we described the spatial and temporal nectar production patterns of Jacaranda oxyphylla, a bee-pollinated species that naturally presents nectarless flowers. Additionally, we compared nectariferous and nectarless floral disks in order to identify histological, subcellular and chemical changes that accompanied the loss of nectar production ability. For that we used standard methods for light and transmission electron microscopy, and gas chromatography coupled to mass spectrometry for chemical analyses. We verified that 47% of flowers did not produce nectar during the whole flower lifespan (nectarless flowers). We also observed remarkable inter-plant variation, with individuals having only nectarless flowers, others only nectariferous ones and most of them showing different proportions of both flower types, with variable nectar volumes (3-21 mu l). Additionally, among nectariferous flowers, we registered two distinct rhythms of nectar production. 'Early' flowers produced nectar from 0 to 24 h, and 'late' flowers produced nectar from 24 to 48 h of anthesis. Although disks from nectariferous and nectarless flowers displayed similar histological organization, they differed strongly at subcellular level. Nectariferous ('early' and 'late') flowers exhibited a cellular apparatus typical of nectar secretion, while nectarless flowers exhibited osmophoric features. We found three aliphatic and one aromatic compound(s) that were detected in both the headspace of flowers and the disks of nectarless flowers, but not the disks of nectariferous flowers Although the remarkable variation in nectar availability may discourage pollinator visits, nectarless flowers might compensate it by producing volatile compounds that can be part of floral scent, acting as chemical attractants. Thus, nectarless flowers may be helping to maintain pollination in this scenario of trophic resource supply scarcity. We suggest that J. oxyphylla can be transitioning from a nectar-based pollination system to another resource-based or even to a deceit mechanism of pollination. Sao Paulo State Univ, Inst Biosci, Dept Bot, Lab Ecol & Evolut Plant Anim Interact, Botucatu, SP, Brazil Sao Paulo State Univ, Inst Biosci, Lab Ecol & Evolut Plant Anim Interact, Grad Program Biol Sci,Dept Bot, Botucatu, SP, Brazil Sao Paulo State Univ, Dept Pharmacol, Lab Phytomed Pharmacol & Biotechnol, Botucatu, SP, Brazil Univ Salzburg, Dept Biosci, Salzburg, Austria Sao Paulo State Univ, Dept Bot, Lab Res Plant Anat & Ultrastruct, Botucatu, SP, Brazil Sao Paulo State Univ, Inst Biosci, Ctr Electron Microscopy, Botucatu, SP, Brazil Sao Paulo State Univ, Inst Biosci, Dept Bot, Lab Ecol & Evolut Plant Anim Interact, Botucatu, SP, Brazil Sao Paulo State Univ, Inst Biosci, Lab Ecol & Evolut Plant Anim Interact, Grad Program Biol Sci,Dept Bot, Botucatu, SP, Brazil Sao Paulo State Univ, Dept Pharmacol, Lab Phytomed Pharmacol & Biotechnol, Botucatu, SP, Brazil Sao Paulo State Univ, Dept Bot, Lab Res Plant Anat & Ultrastruct, Botucatu, SP, Brazil Sao Paulo State Univ, Inst Biosci, Ctr Electron Microscopy, Botucatu, SP, Brazil FAPESP: 2008/55434-7 FAPESP: 2009/17611-7 National Council of Technological and Scientific Development: 446949/2014-0 National Council of Technological and Scientific Development: 470649/2008-9

The goal of this study was to analyse possible structural and ultrastructural differences between the secretory disk of male and functionally female flowers of Tapirira guianensis (Anacardiaceae) at different developmental stages. Studies were carried out using light, scanning and transmission electron microscopy. Biochemical tests were employed to determine the proportion of sugars in the nectar of the floral morphotypes: they were found to be similar, both predominantly composed of sucrose. In addition to sugars, lipids and phenolic substances were identified in anthetic flowers; thus, the secretory disk is a mixed secretion gland, also called a sensu lato nectary. During anthesis, granulocrine and eccrine secretory mechanisms occur in both floral morphotypes. After anthesis and fertilization of the functionally female flower, only the lipophilic and phenolic secretion continues until the early stages of fruit development. An intrastaminal secretory disk that produces both nectar and lipids is reported for the first time in Anacardiaceae. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179, 533–544.

Biotic pollination is critical for tropical ecosystem functioning, and nectar plays an essential role as it represents the main trophic resource for pollinators. Nevertheless, little is known about the mechanisms that underlie its production, which is essential for understanding the basis of nectar-mediated interactions in ecological and evolutionary approaches. Therefore, this study explores the relationship between the nectar secretion pattern and nectary functional changes in Anemopaegma album, a bee-pollinated species. We analysed the pattern of nectar production under field conditions and investigated floral nectary structural changes in two different developmental stages using light, transmission and scanning electron microscopy. We measured 30.95 ± 23.02 μl (mean ± SD, n = 30) of nectar accumulated inside the nectar chamber (29.26 ± 3.48% sucrose equivalents) at the moment of flower opening. Nectar removal did not influence the pattern of floral nectar production in terms of volume or total sugar but reduced the concentration of the nectar produced during the first 24 h of anthesis. The nectary consisted of an epidermis, a nectary parenchyma and a subnectary parenchyma supplied only by phloem. Starch grains decreased in size and abundance from the subnectary parenchyma toward the epidermis. We observed the degradation of starch grains and incorporation of amyloplasts into vacuoles at the pre-anthesis stage as well as the transformation of amyloplasts into elaioplasts during anthesis. Nectar secretion was continuous during the A. album flower life span, which was related to the functional features of its floral nectary, especially the presence of starch stored in the parenchyma.