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1.
J Sci Food Agric ; 102(4): 1488-1497, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34402073

RESUMO

BACKGROUND: Acerola cherry is a famous functional fruit containing plentiful antioxidants and other nutrients. However, studies on the variations among nutrients during the ripening process of acerola fruit are scare. RESULTS: Comparative metabolomic and transcriptomic analyses were performed and identified 31 331 unigenes and 1896 annotated metabolite features in acerola cherry fruit. K Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that several antioxidant and nutrient-related metabolic pathways, such as the flavonoids, vitamins, carotenoids, amino acids, and fatty acids metabolic pathways, were significantly changed during the ripening process. The metabolites related to the vitamin, carotenoid, and fatty acid metabolic pathways were downregulated during the ripening process. Several flavonoid biosynthesis-related genes (including dihydroflavonol 4-reductase, chalcone synthase, flavanone 3-hydroxylase, and anthocyanidin synthase), were significantly upregulated, suggesting their essential functions in the accumulation of flavonoids in mature fruit. CONCLUSION: Most of the vitamin and carotenoid metabolism-related metabolites significantly accumulated in immature fruit, suggesting that immature acerola fruit is a good material for the extraction of vitamins and carotenoids. For macronutrients, most of the amino acids accumulated in mature fruit and most of the fatty acids greatly accumulated in immature fruit. Our data revealed the differential accumulation of antioxidants and nutrients during the ripening process of acerola cherry fruit. © 2021 Society of Chemical Industry.


Assuntos
Malpighiaceae , Antioxidantes , Ácido Ascórbico , Frutas/genética , Regulação da Expressão Gênica de Plantas , Malpighiaceae/genética , Transcriptoma
2.
Mol Biol Rep ; 48(5): 4039-4046, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34014470

RESUMO

Byrsonima Rich. is one of the largest genera of the Malpighiaceae family with 97 species occurrence in Brazil and multiple potentialities, including pharmaceutical and food industries. In this study, 17 microsatellite markers characterized in Byrsonima cydoniifolia were tested for seven related taxa, all species are native to Brazil and four are endemic. Genomic DNA was extracted from leaves tissues and 17 microsatellite markers were used to cross-amplification of microsatellite regions. Polymorphism and genetic diversity were evaluated for B. intermedia, B. verbascifolia, B. laxiflora, B. subterranea, B. umbellata, B. linearifolia. from 16 individuals and for B. viminifolia from 14 individuals. Transferred microsatellite markers panels ranged from 11 (64.8%) in B. viminifolia to 6 (35.2%) in B. umbellata. The total number of alleles per locus ranged from 5 (B. linearifolia) to 8 (B. subterranea) alleles. B. umbellata showed lower values of observed and expected heterozygosity (HO = 0.312; HE = 0.436) and B. subterranea presented the highest values (HO = 0.687; HE = 0.778). A greater number of microsatellite markers should be developed for B. umbellata. The microsatellite marker panels transferred to the species B. intermedia, B. verbascifolia, B. laxiflora, B. subterranea, B. viminifolia and B. linearifolia are very informative, with a high combined probability of exclusion of paternity (Q ≥ 0.976) and the low combined probability of identity (I ≤ 9.91 × 10-6), potentially suitable for future genetic-population studies, supporting strategies for maintaining the genetic diversity and for exploration of Byrsonima species as genetic resources.


Assuntos
Malpighiaceae/genética , Repetições de Microssatélites/genética , Alelos , Brasil , DNA de Plantas/genética , Variação Genética/genética , Polimorfismo Genético/genética
3.
Biochem Genet ; 59(1): 283-299, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33011918

RESUMO

Aspidopterys obcordata var. obcordata, a medicinal plant endemic to China, is a narrowly distributed species and wild resources are extremely limited. To evaluate the genetic variability and degree of genetic divergence of A. obcordata var. obcordata, and to make rational scientific decisions on its harvest and germplasm conservation, we collected 122 samples from across nearly all of its distribution area and studied genetic diversity using inter-simple sequence repeats (ISSRs), sequence-related amplified polymorphisms (SRAPs), and a method combining the two techniques. The results revealed the high genetic diversity of A. obcordata var. obcordata, mainly due to its intra-population diversity, and the top two populations with the highest levels of intra-population diversity were ML and DH, individuals of which can serve as excellent germplasm candidates during the processing of germplasm screening and conservation. In general, the combining method was prior to the ISSR analyses and SRAP analyses results, except for a slight difference in the genetic structure of individual populations. Therefore, we suggest that a combination analysis of the two marker methods is ideal for evaluating the genetic diversity and genetic relationships of A. obcordata var. obcordata.


Assuntos
Variação Genética , Genética Populacional , Malpighiaceae/genética , China , Análise por Conglomerados , Marcadores Genéticos , Geografia , Medicina Tradicional Chinesa , Repetições de Microssatélites , Filogenia , Plantas Medicinais/genética , Polimorfismo Genético , Análise de Componente Principal
4.
Mol Biol Rep ; 47(2): 953-965, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31741258

RESUMO

Understanding into acerola (Malpighia emarginata) molecular and biochemical bases is still obscure, despite it is one of the most important natural source of vitamin C for humans. Recently, our research group published the first data on acerola transcriptome generating valuable information to identify reference genes for RT-qPCR in this species. Hence, this study aimed to identify the most stably expressed genes based on acerola transcriptome data, and further to evaluate the suitability of F-box, U3, Merad50-ATPase, TGD4, NOB1, PA-RNA, RCC1, RBL and PGAL candidates for accurate gene expression normalization in leaf, flower and fruit at 12, 16 and 20 days after anthesis using RT-qPCR analysis. Three algorithms, geNorm, NormFinder, and BestKeeper confirmed the expression stability of all nine candidate reference genes, whereas RefFinder consensually summarized a comprehensive gene ranking. Based on geNorm, the combination of the most stable reference genes RBL and U3 for leaf/flower group, TGD4, F-box and PGAL (fruit developmental stages or fruit/leaf), RCC1, PGAL and RBL (fruit/flower) and RCC1, RBL, TGD4 and PGAL (total samples) were required for accurate normalization. Moreover, the use of these reference genes to assess the expression profile of GMP1 and NAT3 genes confirmed the reliability of ranking and defined the best combination of genes recommended by geNorm and RefFinder. This work will benefit further RT-qPCR studies in these acerola organs by offering a foundation for accurate normalization of gene expression profiling.


Assuntos
Perfilação da Expressão Gênica/normas , Malpighiaceae/genética , Transcriptoma/genética , Algoritmos , Flores/genética , Frutas/genética , Expressão Gênica/genética , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Folhas de Planta/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Padrões de Referência , Reprodutibilidade dos Testes
5.
Plant Mol Biol ; 101(3): 269-296, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31338671

RESUMO

KEY MESSAGE: The first transcriptome coupled to metabolite analyses reveals major trends during acerola fruit ripening and shed lights on ascorbate, ethylene signalling, cellular respiration, sugar accumulation, and softening key regulatory genes. Acerola is a fast growing and ripening fruit that exhibits high amounts of ascorbate. During ripening, the fruit experience high respiratory rates leading to ascorbate depletion and a quickly fragile and perishable state. Despite its growing economic importance, understanding of its developmental metabolism remains obscure due to the absence of genomic and transcriptomic data. We performed an acerola transcriptome sequencing that generated over 600 million reads, 40,830 contigs, and provided the annotation of 25,298 unique transcripts. Overall, this study revealed the main metabolic changes that occur in the acerola ripening. This transcriptional profile linked to metabolite measurements, allowed us to focus on ascorbate, ethylene, respiration, sugar, and firmness, the major metabolism indicators for acerola quality. Our results suggest a cooperative role of several genes involved in AsA biosynthesis (PMM, GMP1 and 3, GME1 and 2, GGP1 and 2), translocation (NAT3, 4, 6 and 6-like) and recycling (MDHAR2 and DHAR1) pathways for AsA accumulation in unripe fruits. Moreover, the association of metabolites with transcript profiles provided a comprehensive understanding of ethylene signalling, respiration, sugar accumulation and softening of acerola, shedding light on promising key regulatory genes. Overall, this study provides a foundation for further examination of the functional significance of these genes to improve fruit quality traits.


Assuntos
Ácido Ascórbico/química , Etilenos/química , Frutas/fisiologia , Malpighiaceae/genética , Malpighiaceae/metabolismo , Transcriptoma , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Transdução de Sinais
6.
Biosci Biotechnol Biochem ; 83(9): 1713-1716, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31023155

RESUMO

Acerola fruits contain abundant ascorbic acid (AsA). The gene expression levels of three upstream enzymes in the primary AsA biosynthesis pathway were correlated with AsA contents in the fruits of two acerola cultivars. Multiple overexpression of the enzymes increased AsA contents, suggesting their high expression is important for high AsA accumulation in acerola fruits and the breeding of AsA-rich plants. Abbreviations: AsA: ascorbic acid; PMI: phosphomannose isomerase; PMM: phosphomannomutase; GMP: GDP-d-mannose pyrophosphorylase; GME: GDP-d-mannose 3',5'-epimerase; GGP: GDP-l-galactose phosphorylase; GPP: l-galactose-1-phosphate phosphatase; GDH: l-galactose dehydrogenase; GLDH: l-galactono-1,4-lactone dehydrogenase.


Assuntos
Ácido Ascórbico/metabolismo , Malpighiaceae/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Malpighiaceae/enzimologia , Malpighiaceae/genética
7.
Sci Rep ; 8(1): 2210, 2018 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-29396532

RESUMO

Byrsonima is the third largest genus (about 200 species) in the Malpighiaceae family, and one of the most common in Brazilian savannas. However, there is no molecular phylogeny available for the genus and taxonomic uncertainties at the generic and family level still remain. Herein, we sequenced the complete chloroplast genome of B. coccolobifolia and B. crassifolia, the first ones described for Malpighiaceae, and performed comparative analyses with sequences previously published for other families in the order Malpighiales. The chloroplast genomes assembled had a similar structure, gene content and organization, even when compared with species from other families. Chloroplast genomes ranged between 160,212 bp in B. crassifolia and 160,329 bp in B. coccolobifolia, both containing 115 genes (four ribosomal RNA genes, 28 tRNA genes and 83 protein-coding genes). We also identified sequences with high divergence that might be informative for phylogenetic inferences in the Malpighiales order, Malpighiaceae family and within the genus Byrsonima. The phylogenetic reconstruction of Malpighiales with these regions highlighted their utility for phylogenetic studies. The comparative analyses among species in Malpighiales provided insights into the chloroplast genome evolution in this order, including the presence/absence of three genes (infA, rpl32 and rps16) and two pseudogenes (ycf1 and rps19).


Assuntos
Variação Genética , Genoma de Cloroplastos , Malpighiaceae/classificação , Malpighiaceae/genética , Filogenia , Brasil , Ordem dos Genes , Genes de Cloroplastos , Sintenia
9.
Genet Mol Res ; 15(4)2016 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-27819718

RESUMO

Malpighia emarginata is cultivated in almost all Brazil and is considered an important agricultural crop. The root-knot nematode Meloidogyne enterolobii has been described as a major threat to this crop, causing great production losses. Due to the scarcity of information about the severity of this parasite in M. emarginata plants in Brazil, this study investigated M. enterolobii resistance of ten M. emarginata genotypes from the active germplasm bank of Universidade Federal Rural de Pernambuco. The experiment was conducted adopting a completely randomized design in a factorial arrangement of 11 x 2 x 5, where M. emarginata cuttings were inoculated with 10,000 eggs in a greenhouse. After 150 days, plants were evaluated for the following parameters: gall index, egg mass index, number of eggs per root system, number of eggs per gram of root, and reproduction factor. The accessions showed different responses depending on host x pathogen interaction, from susceptibility to moderate tolerance. Accessions 027-CMF and 031-CMF were considered tolerant to the nematode and could be of great value in new breeding programs for resistance to M. enterolobii infection.


Assuntos
Malpighiaceae/parasitologia , Parasitos/fisiologia , Sementes/parasitologia , Tylenchoidea/fisiologia , Análise de Variância , Animais , Resistência à Doença , Genótipo , Malpighiaceae/genética , Malpighiaceae/crescimento & desenvolvimento , Doenças das Plantas/parasitologia
10.
Genet Mol Res ; 15(4)2016 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-27813596

RESUMO

Native of the Amazon, the nanche (Byrsonima crassifolia) is a fruit cultivated by family farmers and used in cooking; as such, it represents an opportunity for regional agribusiness. The Embrapa Eastern Amazon set up an active germplasm bank (BAG) consisting of 22 accessions sampled in 11 municipalities of Pará State. Due to its economic potential, there is an interest to advance the genetic breeding program of this species. The aim of this study was to characterize the BAG nanche collection using inter-simple sequence repeat (ISSR) markers. Accessions were genotyped using 23 pre-selected ISSR primers resulting in 109 amplified polymorphic and 51 monomorphic bands. With eight polymorphic bands each, the most polymorphic primers were UBC 809 and UBC 848. An unweighted pair-group method with arithmetic average cluster analysis based on Jaccard's coefficient indicated that the individuals clustered into two distinct groups. Accessions Igarapé Açu-2 and Augusto Corrêa-Pl 1 were most similar. The genetic dissimilarity values ranged from 0.10 to 0.59. We conclude that the ISSR markers were efficient in detecting polymorphisms in the nanche accessions, and that it is possible to infer the genetic variability among accessions of the collection. This demonstrate the importance of using molecular markers in poorly studied species and the advantages that this information can bring to the genetic improvement of such species.


Assuntos
Variação Genética , Malpighiaceae/genética , Repetições de Microssatélites/genética , Sementes/genética , Ecótipo , Marcadores Genéticos , Geografia , Filogenia , Polimorfismo Genético , Temperatura
11.
C R Biol ; 337(1): 62-70, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24439552

RESUMO

Malpighiaceae ovules have a well-developed nucellus; previous observations indicate that during seed development, the endosperm does not proliferate, thus, remaining scarce. This study aimed at identifying the nutritive tissues during seed development in Malpighiaceae, focusing especially on the endosperm. We analysed the seed development of Janusia mediterranea, J. occhionii, Mascagnia cordifolia, and Tetrapterys chamaecerasifolia, which were collected and processed by traditional methods for light microscopy. Ovules are subcampylotropous, crassinucellate and unitegmic in Janusia and bitegmic in M. cordifolia and T. chamaecerasifolia. The nucellus is well developed and protrudes through the micropyle, touching the funicular obturator. During development, a pachychalaza is formed, and the integuments coalesce in bitegmic species. Through a series of nucellar cell divisions, the perisperm is formed. In Janusia species, the endosperm is not produced. In M. cordifolia and T. chamaecerasifolia, the endosperm is nuclear, but it is scarce and ephemeral. The mature seed is exalbuminous, and the perisperm is consumed, and thus, the mature embryo is total. The absence of endosperm in Janusia is newly observed for the family and indicates functional transfer for the abundant perisperm.


Assuntos
Malpighiaceae/fisiologia , Sementes/crescimento & desenvolvimento , Brasil , Endosperma , Flores/química , Frutas/química , Histocitoquímica , Malpighiaceae/genética , Valor Nutritivo , Óvulo Vegetal/química , Sementes/química
12.
Genet Mol Res ; 12(4): 5145-51, 2013 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-24301774

RESUMO

Brazil is the world's largest producer of acerola, Malpighia emarginata (Malpighiaceae); the Northeast is responsible for 60% of the national production. The culture of acerola in Brazil has great genetic variability; plantings have high phenotypic diversity and are not very productive, often originating from propagation by seed. We evaluated the genetic diversity of 42 accessions from the Acerola Active Germplasm Bank of Universidade Federal de Pernambuco. Using 15 RAPD primers, 182 markers were obtained, of which 166 were polymorphic and 16 were monomorphic. We found high genetic variability among the accessions (HE = 0.29), with no redundancy. Considering the accessions from the states of Pernambuco, Bahia and Pará as distinct groups, there was greater diversity in accessions from Bahia than from the other two states.


Assuntos
Bancos de Espécimes Biológicos , Variação Genética , Malpighiaceae/genética , Brasil , Geografia , Malpighiaceae/classificação , Filogenia , Locos de Características Quantitativas
13.
Phytochemistry ; 92: 42-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23747094

RESUMO

We have characterised the FAD2 gene family from Hiptage benghalensis, a tropical plant that accumulates high levels of ricinoleic acid in its seeds. Functional characterisation of six FAD2 gene family members showed that two of them were capable of functioning as Δ12-hydroxylases while the other FAD2 members were confirmed to be Δ12-desaturases. The Δ12-hydroxylation function of these two genes was confirmed in yeast cells, using C16:1(Δ9) and C18:1(Δ9) monounsaturated fatty acids as substrates. These Δ12-hydroxylases, like the other Δ12-hydroxylases previously cloned from plants Ricinus communis (castor), Physaria fendleri and fungus Claviceps purpurea, also showed some Δ12-desaturase activity. The hydroxylation activity of the two Hiptage hydroxylases was further confirmed by their expression in the Arabidopsis fad2/fae1 double mutant where they were able to produce equivalent or higher levels hydroxylated fatty acids in the seed oil when compared with the other known hydroxylases.


Assuntos
Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Malpighiaceae/genética , Malpighiaceae/metabolismo , Ácidos Ricinoleicos/metabolismo , Sequência de Aminoácidos , Biocatálise , Clonagem Molecular , Malpighiaceae/enzimologia , Dados de Sequência Molecular , Ácidos Ricinoleicos/química , Sementes/química , Sementes/metabolismo
14.
Proc Natl Acad Sci U S A ; 109(43): 17519-24, 2012 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-23045684

RESUMO

The angiosperm order Malpighiales includes ~16,000 species and constitutes up to 40% of the understory tree diversity in tropical rain forests. Despite remarkable progress in angiosperm systematics during the last 20 y, relationships within Malpighiales remain poorly resolved, possibly owing to its rapid rise during the mid-Cretaceous. Using phylogenomic approaches, including analyses of 82 plastid genes from 58 species, we identified 12 additional clades in Malpighiales and substantially increased resolution along the backbone. This greatly improved phylogeny revealed a dynamic history of shifts in net diversification rates across Malpighiales, with bursts of diversification noted in the Barbados cherries (Malpighiaceae), cocas (Erythroxylaceae), and passion flowers (Passifloraceae). We found that commonly used a priori approaches for partitioning concatenated data in maximum likelihood analyses, by gene or by codon position, performed poorly relative to the use of partitions identified a posteriori using a Bayesian mixture model. We also found better branch support in trees inferred from a taxon-rich, data-sparse matrix, which deeply sampled only the phylogenetically critical placeholders, than in trees inferred from a taxon-sparse matrix with little missing data. Although this matrix has more missing data, our a posteriori partitioning strategy reduced the possibility of producing multiple distinct but equally optimal topologies and increased phylogenetic decisiveness, compared with the strategy of partitioning by gene. These approaches are likely to help improve phylogenetic resolution in other poorly resolved major clades of angiosperms and to be more broadly useful in studies across the Tree of Life.


Assuntos
Genoma de Planta , Malpighiaceae/genética , Filogenia , Funções Verossimilhança , Malpighiaceae/classificação , Dados de Sequência Molecular , Especificidade da Espécie
15.
PLoS One ; 7(4): e36033, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22558314

RESUMO

The repeated origin of similar phenotypes is invaluable for studying the underlying genetics of adaptive traits; molecular evidence, however, is lacking for most examples of such similarity. The floral morphology of neotropical Malpighiaceae is distinctive and highly conserved, especially with regard to symmetry, and is thought to result from specialization on oil-bee pollinators. We recently demonstrated that CYCLOIDEA2-like genes (CYC2A and CYC2B) are associated with the development of the stereotypical floral zygomorphy that is critical to this plant-pollinator mutualism. Here, we build on this developmental framework to characterize floral symmetry in three clades of Malpighiaceae that have independently lost their oil bee association and experienced parallel shifts in their floral morphology, especially in regard to symmetry. We show that in each case these species exhibit a loss of CYC2B function, and a strikingly similar shift in the expression of CYC2A that is coincident with their shift in floral symmetry. These results indicate that similar floral phenotypes in this large angiosperm clade have evolved via parallel genetic changes from an otherwise highly conserved developmental program.


Assuntos
Evolução Biológica , Flores/anatomia & histologia , Flores/genética , Malpighiaceae/anatomia & histologia , Malpighiaceae/genética , Flores/crescimento & desenvolvimento , Flores/ultraestrutura , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Malpighiaceae/ultraestrutura , Fenótipo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Am J Bot ; 99(3): e111-3, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22358043

RESUMO

PREMISE OF THE STUDY: We developed and characterized microsatellite markers for Byrsonima crassifolia (Malpighiaceae), a widely distributed neotropical fruit tree. METHODS AND RESULTS: Eight polymorphic and two monomorphic microsatellite loci were identified and screened in 60 samples from four geographically disparate populations (Bolivia, Brazil, Mexico, and Panama). Each locus exhibited between two and 11 alleles. Expected heterozygosity ranged from 0 to 0.839. All loci amplify in the congeners B. variabilis and B. basiloba, four amplify in B. bucidaefolia, and seven amplify in B. variabilis, although levels of polymorphism have not been assessed. CONCLUSIONS: These loci will provide novel tools for comparing genetic diversity present in cultivated and noncultivated populations of B. crassifolia throughout its range, and may prove valuable in related species.


Assuntos
Malpighiaceae/genética , Repetições de Microssatélites/genética , DNA de Plantas/genética , Demografia , Polimorfismo Genético , América do Sul , Especificidade da Espécie
17.
Ann Bot ; 107(8): 1323-34, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21610210

RESUMO

BACKGROUND AND AIMS: Most Neotropical species of Malpighiaceae produce floral fatty oils in calyx glands to attract pollinating oil-collecting bees, which depend on this resource for reproduction. This specialized type of pollination system tends to be lost in members of the family that occur outside the geographic distribution (e.g. Africa) of Neotropical oil-collecting bees. This study focused on the pollination ecology, chemical ecology and reproductive biology of an oil flower species, Pterandra pyroidea (Malpighiaceae) from the Brazilian Cerrado. Populations of this species consist of plants with oil-secreting (glandular) flowers, plants with non-oil-secreting flowers (eglandular) or a mix of both plant types. This study specifically aims to clarify the role of eglandular morphs in this species. METHODS: Data on pollinators were recorded by in situ observations. Breeding system experiments were conducted by isolating inflorescences and by enzymatic reactions. Floral resources, pollen and floral oils offered by this species were analysed by staining and a combination of various spectroscopic methods. KEY RESULTS: Eglandular flowers of P. pyroidea do not act as mimics of their oil-producing conspecifics to attract pollinators. Instead, both oil-producing and oil-free flowers depend on pollen-collecting bees for reproduction, and their main pollinators are bumble-bees. Floral oils produced by glandular flowers are less complex than those described in closely related genera. CONCLUSIONS: Eglandular flowers represent a shift in the pollination system in which oil is being lost and pollen is becoming the main reward of P. pyroidea flowers. Pollination shifts of this kind have hitherto not been demonstrated empirically within Neotropical Malpighiaceae and this species exhibits an unusual transition from a specialized towards a generalized pollination system in an area considered the hotspot of oil-collecting bee diversity in the Neotropics. Transitions of this type provide an opportunity to study ongoing evolutionary mechanisms that promote the persistence of species previously involved in specialized mutualistic relationships.


Assuntos
Abelhas/fisiologia , Flores/fisiologia , Malpighiaceae/fisiologia , Óleos de Plantas/metabolismo , Polinização/fisiologia , Animais , Comportamento Animal , Evolução Biológica , Brasil , Cruzamento , Ecologia , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Feminino , Funções Verossimilhança , Modelos Logísticos , Masculino , Malpighiaceae/química , Malpighiaceae/genética , Fenótipo , Óleos de Plantas/análise , Pólen/fisiologia , Reprodução/fisiologia
18.
J Plant Physiol ; 168(6): 619-27, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-20933298

RESUMO

Acerola (Malpighia glabra) is an exotic fruit cultivated primarily for its abundant ascorbic acid (AsA) content. The molecular mechanisms that regulate the metabolism of AsA in acerola have yet to be defined. Monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) are key enzymes of the ascorbate-glutathione cycle that maintain reduced pools of ascorbic acid and serve as important antioxidants. cDNAs encoding MDHAR and DHAR were isolated from acerola using RT-PCR and RACE. Phylogenetic trees associated acerola MDHAR and DHAR with other plant cytosolic MDHARs and DHARs. Expressions of the two genes correlated with their enzymatic activities and were differentially regulated during fruit ripening. Interestingly, MDHAR expression was only detected in overripe fruits, whereas the transcript level of DHAR was highest at the intermediate stage of fruit ripening. Under dark conditions, there was a sharp and significant decline in the total and reduced ascorbate contents, accompanied by a decrease in the level of transcripts and enzyme activities of the two genes in acerola leaves. MDHAR and DHAR transcripts and enzyme activities were significantly up-regulated in the leaves of acerola under cold and salt stress conditions, indicating that expression of both genes are transcriptionally regulated under these stresses.


Assuntos
Ácido Ascórbico/metabolismo , Malpighiaceae/enzimologia , Malpighiaceae/genética , NADH NADPH Oxirredutases/genética , Oxirredutases/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , DNA Complementar/genética , Frutas/genética , Frutas/metabolismo , Frutas/efeitos da radiação , Regulação da Expressão Gênica de Plantas , Malpighiaceae/metabolismo , Malpighiaceae/efeitos da radiação , Dados de Sequência Molecular , NADH NADPH Oxirredutases/química , NADH NADPH Oxirredutases/metabolismo , Oxirredutases/química , Oxirredutases/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , Salinidade , Alinhamento de Sequência , Estresse Fisiológico , Temperatura
19.
An Acad Bras Cienc ; 82(4): 868-79, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21152761

RESUMO

The genus Heteropterys is one of the major genera in Malpighiaceae. However, few cytological and palynological studies were reported. The present work described for the first time the chromosome number, heterochromatin pattern, meiotic behavior, pollen viability and palynological aspects of Heteropterys ubellata, a very spread species. One large Brazilian population was evaluated using conventional techniques for meiotic studies and acetolyse to access the pollen morphology. The species showed 2n = 20 chromosomes, normal meiotic development and viable pollens. Great blocks of heterochromatin were observed around the centromers. DAPI staining was positive for centroeric heterochroatin, hile CMA3 ark as observed just at terinal regions of one pair of hoologues chromosomes. This result and the presence of one chromosome pair attached to the nucleoli during the pachytene and diakinesis suggested the presence of only one pair of NORs. Palynological analysis revealed that pollen grains are apolar, 6 porate and with colpoids associated to all pores. The pollen content was positive for the starch test, and the exine was rugulate with little psilate regions.


Assuntos
Cromossomos de Plantas/genética , Heterocromatina/genética , Malpighiaceae/citologia , Brasil , Bandeamento Cromossômico , Cariotipagem , Malpighiaceae/classificação , Malpighiaceae/genética
20.
An. acad. bras. ciênc ; 82(4): 868-879, Dec. 2010. ilus
Artigo em Inglês | LILACS | ID: lil-567797

RESUMO

The genus Heteropterys is one of the major genera in Malpighiaceae. However, few cytological and palynological studies were reported. The present work described for the first time the chromosome number, heterochromatin pattern, meiotic behavior, pollen viability and palynological aspects of Heteropterys ubellata, a very spread species. One large Brazilian population was evaluated using conventional techniques for meiotic studies and acetolyse to access the pollen morphology. The species showed 2n = 20 chromosomes, normal meiotic development and viable pollens. Great blocks of heterochromatin were observed around the centromers. DAPI staining was positive for centroeric heterochroatin, hile CMA3 ark as observed just at terinal regions of one pair of hoologues chromosomes. This result and the presence of one chromosome pair attached to the nucleoli during the pachytene and diakinesis suggested the presence of only one pair of NORs. Palynological analysis revealed that pollen grains are apolar, 6 porate and with colpoids associated to all pores. The pollen content was positive for the starch test, and the exine was rugulate with little psilate regions.


O gênero Heteropterys é um dos maiores gêneros entre as Malpighiaceae. Entretanto, poucos estudos citológicos e palinológicos foram relatados. O presente trabalho descreveu pela primeira vez o número cromossômico, o padrão heterocromático, o comportamento meiótico, a viabilidade polínica e aspectos palinológicos de Heteropterys umbellata, uma espécie muito disseminada. Uma grande população brasileira foi estudada utilizando técnicas convencionais para o estudo de cromossomos meióticos e acetólise para acessar a morfologia polínica. A espécie apresentou 2n = 20 cromossomos, desenvolvimento meiótico normal e pólens viáveis. Grandes blocos de heterocromatina foram observados ao redor dos cen-trômeros. A coloração com DAPI foi positiva para a hetero-cromatina centromérica, enquanto marcas com CMA3 foram observadas somente em um sítio terminal de um par de cromossomos homólogos. Este resultado e a presença de um par de cromossomos associados a um nucléolo durante o paquíteno e diacinese sugerem a presença de somente um par de RONs. A análise palinológica revelou que os grãos de pólen são apolar, com 6 poros e colpóides associados a todos eles. O conteúdo polínico foi positivo para o teste de amido e a exina mostrou-se rugulada com poucas regiões psiladas.


Assuntos
Cromossomos de Plantas/genética , Heterocromatina/genética , Malpighiaceae/citologia , Brasil , Bandeamento Cromossômico , Cariotipagem , Malpighiaceae/classificação , Malpighiaceae/genética
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