|
| | 1. |
2008 Dec 16 |
Disturbance-response analysis: a method for rapid assessment of the threat to species in disturbed areas.
Martorell C, Peters EM
Conserv. Biol. 2009 Apr;23(2):377-87. Epub 2008 Dec 16.
Abstract
We developed a method with which to analyze a specie's response to chronic anthropogenic disturbance (CAD). We regressed density of individuals on the intensity of 3 disturbance agents (human activities, raising livestock, and land degradation) along CAD gradients to determine how much CAD is experienced by a species; whether species are ruderal (achieving maximum densities in disturbed sites); whether density declines as a result of CAD; which disturbance agents are responsible for this reduction; and the number of populations that decline as a result of CAD. We tested the method on 9 threatened Mammillaria species (Cactaceae). Seven species were ruderal. In 4 species, actual disturbance surpassed the CAD intensity in which plants achieved their maximum densities; thus, the density of those 4 species appeared to be declining. For 7 species, some populations were threatened by human activities or livestock, whereas others were favored by them. Land degradation negatively affected all species. Our results allowed us to distinguish 4 groups of species that had similar responses and thus may require different forms of management. Our method provided an estimation of the growth rate (lambda) of the studied populations that was significantly correlated with lambdas obtained from demographic studies. The size structures of populations were consistent with the predictions of the analysis, which suggests our results are consistent and reliable. Disturbance-response analysis provides a basis for management in heavily populated areas, where conservation must be achieved along with development activities that cause CAD. The method provides readily interpretable information, which facilitates participative decision making; the data are rapidly generated, which makes it appropriate when results are required promptly or for assessment of large numbers of species; and it provides a comprehensive perception of how threatened species behave in the real world.
[Pubmed: 19183208]
| | 2. |
1986 Apr |
Leaf and Stem CO(2) Uptake in the Three Subfamilies of the Cactaceae.
Nobel PS, Hartsock TL
Plant Physiol. 1986 Apr;80(4):913-917.
Abstract
Net CO(2) uptake over 24-hour periods was examined for the leaves and for the stems of 11 species of cacti representing all three subfamilies. For Pereskia aculeata, Pereskia grandifolia, and Maihuenia poeppigii (subfamily Pereskioideae), all the net shoot CO(2) uptake was by the leaves and during the daytime. In contrast, for the leafless species Carnegiea gigantea, Ferocactus acanthodes, Coryphantha vivipara, and Mammillaria dioica (subfamily Cactoideae), all the shoot net CO(2) uptake was by the stems and at night. Similarly, for leafless Opuntia ficus-indica (subfamily Opuntioideae), all net CO(2) uptake occurred at night. For leafy members of the Opuntioideae (Pereskiopsis porteri, Quiabentia chacoensis, Austrocylindropuntia subulata), at least 88% of the shoot CO(2) uptake over 24 hours was by the leaves and some CO(2) uptake occurred at night. Leaves responded to the instantaneous level of photosynthetically active radiation (PAR) during the daytime, as occurs for C(3) plants, whereas nocturnal CO(2) uptake by stems of O. ficus-indica and F. acanthodes responded to the total daily PAR, as occurs for Crassulacean acid metabolism (CAM) plants. Thus, under the well-watered conditions employed, the Pereskioideae behaved as C(3) plants, the Cactoideae behaved as CAM plants, and the Opuntioideae exhibited characteristics of both pathways.
[Pubmed: 16664741]
| | 3. |
2002 Dec 07 |
Epidermal and hypodermal characteristics in North American Cactoideae (Cactaceae).
Loza-Cornejo S, Terrazas T
J. Plant Res. 2003 Feb;116(1):27-35. Epub 2002 Dec 07.
Abstract
Dermal and hypodermal anatomical features of 70 species representing 21 genera of North American Cactoideae were studied. Results show that all species examined have parallelocytic stomata and anticlinal wall surface varies from straight to undulate. Cuticle thickness is mostly narrow (1-10 microm) contrary to the general opinion that cuticle is thick in most cacti; however, few species such as Ariocarpus fissuratus and several species of Pachycereus show a distinctive thick cuticle. More than 80% of the species studied have a single-layered epidermis. Papillae occur in eight species belonging to four genera. Notable papillae are a feature shared by all members of Peniocereus subg. Peniocereus. Other species show a bullate surface produced by irregular patches of secondary epidermal cell divisions. Commonly, the hypodermis is composed of more than two cell layers with distinctive collenchymatous walls as reported in many South American species. Silica bodies, prismatic crystals, druses, sphaerocrystals, and tannins are the most common cellular inclusions that distinguish several genera and appear to have taxonomic value. However, a more thorough search in species of Cephalocereus, Coryphantha, Echinocereus, Mammillaria, Neobuxbaumia, Pilosocereus, and Turbinicarpus is needed to support the previous assertion.
[Pubmed: 12605297]
| | 4. |
2008 Mar 29 |
Extensive 5.8S nrDNA polymorphism in Mammillaria (Cactaceae) with special reference to the identification of pseudogenic internal transcribed spacer regions.
Harpke D, Peterson A
J. Plant Res. 2008 May;121(3):261-70. Epub 2008 Mar 29.
Abstract
The internal transcribed spacer (ITS) region (ITS1, 5.8S rDNA, ITS2) represents the most widely applied nuclear marker in eukaryotic phylogenetics. Although this region has been assumed to evolve in concert, the number of investigations revealing high degrees of intra-individual polymorphism connected with the presence of pseudogenes has risen. The 5.8S rDNA is the most important diagnostic marker for functionality of the ITS region. In Mammillaria, intra-individual 5.8S rDNA polymorphisms of up to 36% and up to nine different types have been found. Twenty-eight of 30 cloned genomic Mammillaria sequences were identified as putative pseudogenes. For the identification of pseudogenic ITS regions, in addition to formal tests based on substitution rates, we attempted to focus on functional features of the 5.8S rDNA (5.8S motif, secondary structure). The importance of functional data for the identification of pseudogenes is outlined and discussed. The identification of pseudogenes is essential, because they may cause erroneous phylogenies and taxonomic problems.
[Pubmed: 18373158]
| | 5. |
2008 |
Severe hypoxia and multiple infarctions resembling Creutzfeldt-Jakob disease.
Mittelbronn M, Capper D, Bader B, Schittenhelm J, Haybaeck J, Weber P, Meyermann R, Kretzschmar HA, Wietholter H
Folia Neuropathol. 2008;46(2):149-53.
Abstract
Although neuropathological examination is still required for the definite diagnosis of Creutzfeldt-Jakob disease (CJD), specialised clinical assessment predicts probable CJD. Here we present a 73-year-old female patient presenting with rapid cognitive decline, visual, acoustic and cerebellar disturbances, ataxia and EEG changes compatible with early CJD stages. MRI revealed hyperintensities within the thalami, hypothalami, corpora mammillaria, the tectum and the cortex. Initial neuropathological examination showed severe cortical and subcortical spongiosis. However, both immunohistochemistry and Western blotting showed no pathological prion protein. Finally, small infarctions affecting the tectum, tegmentum, corpora mammillaria and global hypoxic-ischaemic changes could be identified as the probable reason for the changes interpreted as CJD-related pathology. Hypoxic-ischaemic CNS alterations mainly affecting the supply area of the basilar artery should be ruled out in case of probable CJD. In addition, severe spongiosis can be misleading in the histological examination, suggesting the diagnosis of a prion-induced spongiform encephalopathy.
[Pubmed: 18587709]
| | 6. |
2007 Aug 21 |
Mammillarinin: a new malonylated betacyanin from fruits of Mammillaria.
Wybraniec S, Nowak-Wydra B
J. Agric. Food Chem. 2007 Oct 3;55(20):8138-43. Epub 2007 Aug 21.
Abstract
A new betacyanin endogenously occurring in fruits of nine Mammillaria species, i.e., M. roseo-alba (Boedecker), M. donatii (Berge), M. coronata (Scheidweiler), M. karwinskiana (Martius), M. gummifera (Engelmann), M. infernillensis (Craig), M. centricirrha (Lemaire), M. krameri (Muehlenpfordt), and M. magnimamma (Haworth), was studied by means of spectroscopic techniques. The betacyanin was identified as betanidin 5-O-(6'-O-malonyl)-beta-sophoroside for which the trivial name mammillarinin is proposed. In some Mammillaria species this compound was reported as a dominating pig-ment. Except for its epimer, two other isomers of mammillarinin were tentatively identified as betanidin/isobetanidin 5-O-(4'-O-malonyl)-beta-sophoroside present in the fruits as acyl migration products.
[Pubmed: 17711293]
| | 7. |
2007 Jul |
Assessment of N-glycan heterogeneity of cactus glycoproteins by one-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
Balen B, Krsnik-Rasol M, Zamfir AD, Zadro I, Vakhrushev SY, Peter-Katalinic J
J Biomol Tech. 2007 Jul;18(3):162-72.
Abstract
Artificial environmental conditions in tissue culture, such as elevated relative humidity and rich nutrient medium, can influence and modify tissue growth and induce spontaneous changes from characteristic organization pattern to unorganized callus. As succulent plants with crassulacean acid metabolism, cacti are particularly susceptible to this altered growth environment. Glycosylated proteins of Mammillaria gracillis tissues cultivated in vitro, separated by SDS-PAGE, were detected with Con A after the transfer of proteins onto the nitrocellulose membrane. The glycan components were further characterized by affinity blotting with different lectins (GNA, DSA, PNA, and RCA(120)). The results revealed significant differences in glycoprotein pattern among the investigated cactus tissues (shoot, callus, hyperhydric regenerant, and tumor). To test whether the N-glycosylation of the same protein can vary in different developmental stages of cactus tissue, the N-glycans were analyzed by MALDI-TOF MS after in-gel deglycosylation of the excised 38-kDa protein band. Paucimannosidic-type N-glycans were detected in oligosaccharide mixtures from shoot and callus, while the hyperhydric regenerant and tumor shared glycans of complex type. The hybrid oligosaccharide structures were found only in tumor tissue. These results indicate that the adaptation of plant cells to artificial environment in tissue culture is reflected in N-glycosylation, and structures of N-linked glycans vary with different developmental stages of Mammillaria gracillis tissues.
[Pubmed: 17595312]
| | 8. |
2006 Jun 06 |
Non-concerted ITS evolution in Mammillaria (Cactaceae).
Harpke D, Peterson A
Mol. Phylogenet. Evol. 2006 Dec;41(3):579-93. Epub 2006 Jun 06.
Abstract
Molecular studies of 21 species of the large Cactaceae genus Mammillaria representing a variety of intrageneric taxonomic levels revealed a high degree of intra-individual polymorphism of the internal transcribed spacer region (ITS1, 5.8S rDNA, ITS2). Only a few of these ITS copies belong to apparently functional genes, whereas most are probably non-functional (pseudogenes). As a multiple gene family, the ITS region is subjected to concerted evolution. However, the high degree of intra-individual polymorphism of up to 36% in ITS1 and up to 35% in ITS2 suggests a non-concerted evolution of these loci in Mammillaria. Conserved angiosperm motifs of ITS1 and ITS2 were compared between genomic and cDNA ITS clones of Mammillaria. Some of these motifs (e.g., ITS1 motif 1, 'TGGT' within ITS2) in combination with the determination of GC-content, length comparisons of the spacers and ITS2 secondary structure (helices II and III) are helpful in the identification of pseudogene rDNA regions.
[Pubmed: 16843685]
| | 9. |
2006 Jul |
Glycoproteomic survey of Mammillaria gracillis tissues grown in vitro.
Balen B, Krsnik-Rasol M, Zamfir AD, Milosević J, Vakhrushev SY, Peter-Katalinić J
J. Proteome Res. 2006 Jul;5(7):1658-66.
Abstract
The structure elucidation of protein-linked N-glycans in plants has raised interest in the past years due to remarkable physiological roles attributed to these modifications. However, little information about the glycoprotein patterns related to plant cell differentiation, dedifferentiation and transformation is available. In this work, the use of two-dimensional polyacrylamide gel electrophoresis in conjunction with matrix assisted laser/desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS) for the characterization of carbohydrates released from plant glycoproteins is described. Proteins from different Mammillaria tissues (shoot, callus, hyperhydric regenerant, and TW tumor) were separated by 2D SDS-polyacrylamide gel electrophoresis, transferred to a nitrocellulose membrane and incubated with Con A to detect N-glycosylated proteins. To discover if the same protein can have various N-glycan structures depending on the organization status of the tissue, the selected glycoprotein spot, which was common for all investigated tissues, was excised from the gels and digested by PNGase A. The released oligosaccharides were analyzed by MALDI-TOF-MS. The results obtained in this study indicate that the N-glycosylation pattern of the protein is clearly dependent on level of plant tissue organization and can be related to the specific morphogenic status.
[Pubmed: 16823973]
| | 10. |
|
Genomic relations among 31 species of Mammillaria haworth (Cactaceae) using random amplified polymorphic DNA.
Mattagajasingh I, Mukherjee AK, Das P
Z. Naturforsch., C, J. Biosci.;61(7-8):583-91.
Abstract
Thirty-one species of Mammillaria were selected to study the molecular phylogeny using random amplified polymorphic DNA (RAPD) markers. High amount of mucilage (gelling polysaccharides) present in Mammillaria was a major obstacle in isolating good quality genomic DNA. The CTAB (cetyl trimethyl ammonium bromide) method was modified to obtain good quality genomic DNA. Twenty-two random decamer primers resulted in 621 bands, all of which were polymorphic. The similarity matrix value varied from 0.109 to 0.622 indicating wide variability among the studied species. The dendrogram obtained from the unweighted pair group method using arithmetic averages (UPGMA) analysis revealed that some of the species did not follow the conventional classification. The present work shows the usefulness of RAPD markers for genetic characterization to establish phylogenetic relations among Mammillaria species.
[Pubmed: 16989321]
| | 11. |
2003 Nov |
Isoenzymes of peroxidase and esterase related to morphogenesis in Mammillaria gracillis Pfeiff. tissue culture.
Balen B, Krsnik-Rasol M, Simeon-Rudolf V
J. Plant Physiol. 2003 Nov;160(11):1401-6.
Abstract
In vitro propagated plants of the cactus Mammillaria gracillis Pfeiff. (Cactaceae) spontaneously produced callus. The habituated callus regenerated normal and hyperhydric shoots without the addition of grown regulators. Tumours were obtained by infecting cactus explants with Agrobacterium tumefaciens; the wild strain B6S3 (tumour TW) or with the rooty mutant GV3101 (tumour TR). Both tumour lines grew vigorously, never expressing any morphogenic potential. In this study, cactus shoots, callus, normal and hyperhydric regenerants and TW and TR tumours were compared with regard to peroxidase (EC 1.11.1.7) and esterase activity, and isoenzyme patterns. Guaiacol peroxidase activity was the lowest in the cactus shoots and in the normal regenerants. Callus, hyperhydric regenerants and tumours had peroxidase activity of 6 to 7 times higher. Esterase activity was measured with 1- and 2-naphthylacetate as broad-spectrum substrates. The highest esterase activity was determined in tumours with both substrates. All tissues, except the TR tumour, had higher esterase activity for 2-compared to 1-naphtylacetate. Peroxidase and esterase isoenzyme patterns were not completely identical among the investigated tissues.
[Pubmed: 14658394]
| | 12. |
|
Histochemical demonstration of folic acid metabolism, some lysosomal activities and NADH2-cytochrome-C-reductase in corpora mammillaria in the ageing process.
Onicescu D, Popescu M
Rom J Morphol Embryol.;39(1-2):3-7.
Abstract
In bovine corpora mammillaria of young animals, a folic acid positive reaction was found in the neurons and in the neuroglia, in parallel with high dihydrofolate-reductase activity in the nerve cells. In old animals, folate and lysosome enzymes were different in the lateral and in medial nucleus, the highest amount being observed in the lateral nucleus; in the glial cells the lysosomal enzymes increased and in the nerve cells the concentration of folic acid increased. In the medial nucleus only relatively few enzyme modifications in the process of senescence were noticed.
[Pubmed: 8032017]
| | 13. |
1979 Jan |
Hallucinogenic plants of the Tarahumara.
Bye RA
J Ethnopharmacol. 1979 Jan;1(1):23-48.
Abstract
Plants used by the Mexican Tarahumara Indians to alter their perception are discussed from an ethnobotanical viewpoint. Reports from earlier workers are reviewed. Recent field work has corroborated many of the early observations. In addition, five Tarahumara plants are reported for the first time as hallucinogenic. They include species of Coryphantha, Echinocereus, Mammillaria, and Scirpus. Other plants are suspected of producing hallucinations or are associated with hallucinogenic plants.
[Pubmed: 544948]
| | 14. |
1973 Sep |
Cactus alkaloids. 28. Phenolic beta-phenethylamines from Mammillaria elongata.
West LG, McLaughlin JL
Lloydia. 1973 Sep;36(3):346-8.
[Pubmed: 4761751]
| | 15. |
1967 Nov |
A chemical study of Mammillaria runyoni. The isolation of acetovanillone and a new triterpenoid, mamillarol.
Domínguez XA, Pugliese O
Planta Med. 1967 Nov;15(4):401-3.
[Pubmed: 5603482]
| | 16. |
1951 Aug |
Anhidrotic heat exhaustion (anhidrotic asthenia) and mammillaria (miliaria profunda).
O'BRIEN JP
Trans. R. Soc. Trop. Med. Hyg. 1951 Aug;45(1):139-43.
[Pubmed: 14876775]
| | 17. |
1951 Aug |
Comparative physiological observations on prickly heat, mammillaria and anhidrotic heat exhaustion.
HORNE GO, MOLE RH
Trans. R. Soc. Trop. Med. Hyg. 1951 Aug;45(1):79-90.
[Pubmed: 14876767]
| | 18. |
1951 Feb |
Mammillaria.
HORNE GO, MOLE RH
Trans. R. Soc. Trop. Med. Hyg. 1951 Feb;44(4):465-71.
[Pubmed: 14817822]
| | 19. |
2010 Jan |
Neurological picture. Acute Wernicke's encephalopathy with hyperechogenic corpora mammillaria in brain sonography.
Günther A, Berg D, Joachimski F, Ragoschke-Schumm A, Redecker C
J. Neurol. Neurosurg. Psychiatr. 2010 Jan;81(1):114-5.
[Pubmed: 20019230]
| | 20. |
1983 Jun |
Regional patterns of blood-brain barrier breakdown during epileptiform seizures induced by various convulsive agents.
Nitsch C, Klatzo I
J. Neurol. Sci. 1983 Jun;59(3):305-22.
Abstract
In unrestrained rabbits with generalized epileptic seizures induced by systemic application of convulsant drugs, regional changes in blood-brain barrier (BBB) permeability to macromolecules were investigated using Evans Blue (EB) as indicator. BBB leakage due to seizures was present only in animals in which the mean arterial blood pressure rose about 50 mm Hg with the onset of convulsive motor activity. However, a blood pressure increase was not necessarily associated with the occurrence of BBB opening. Pentylenetetrazole-induced seizures resulted in bilateral EB leakage mainly in the hypothalamus, with exception of the mammillary bodies, and the preoptic area, and they were associated, in most cases, with an intensive staining of the cerebellum and also of the midbrain tegmentum. In contrast, seizures due to the GABA receptor blocker bicuculline brought about a penetration of the dye in the region of the pallidum, whereas the GABA synthesis inhibitor methoxypyridoxine produced BBB breakdown in the hippocampus. Methionine-sulfoximine convulsions resulted in a selective stain of the corpora mammillaria, and kainic acid induced a diffuse leakage in neocortical brain areas. As a rule, BBB breakdown was bilateral and confined to anatomically limited brain areas, suggesting that BBB integrity was not only disturbed by abrupt increases in the intraluminal pressure, but was also influenced from the brain tissue. The fluorescence microscopic observations revealed that the tracer penetrated into the neuropil through larger vessels. It had the tendency to accumulate in neurons. In case of the hippocampus, CA2 pyramidal cells revealed more intense uptake of EB than those of the adjacent fields.
[Pubmed: 6875604]
| | 21. |
2010 Jul 1 |
Spine micromorphology of normal and hyperhydric Mammillaria gracilis Pfeiff. (Cactaceae) shoots.
Peharec P, Posilović H, Balen B, Krsnik-Rasol M
J Microsc. 2010 Jul 1;239(1):78-86.
Abstract
Artificial conditions of tissue culture affect growth and physiology of crassulacean acid metabolism plants which often results in formation of hyperhydric shoots. In in vitro conditions Mammillaria gracilis Pfeiff. (Cactaceae) growth switches from organized to unorganized way, producing a habituated organogenic callus which simultaneously regenerates morphologically normal as well as altered hyperhydric shoots. In this study, influence of tissue culture conditions on morphology of cactus spines of normal and hyperhydric shoots was investigated. Spines of pot-grown Mammillaria plants and of in vitro regenerated shoots were examined with stereo microscope and scanning electron microscope. The pot-grown plants had 16-17 spines per areole. In vitro grown normal shoots, even though they kept typical shoot morphology, had lower number of spines (11-12) and altered spine morphology. This difference was even more pronounced in spine number (six to seven) and morphology of the hyperhydric shoots. Scanning electron microscopy analysis revealed remarkable differences in micromorphology of spine surface between pot-grown and in vitro grown shoots. Spines of in vitro grown normal shoots showed numerous long trichomes, which were more elongated on spines of the hyperhydric shoots; the corresponding structures on spine surface of pot-grown plants were noticed only as small protrusions. Scanning electron microscopy morphometric studies showed that the spines of pot-grown plants were significantly longer compared to the spines of shoots grown in tissue culture. Moreover, transverse section shape varies from elliptical in pot-grown plants to circular in normal and hyperhydric shoots grown in vitro. Cluster and correspondence analyses performed on the scanning electron microscope obtained results suggest great variability among spines of pot-grown plants. Spines of in vitro grown normal and hyperhydric shoots showed low level of morphological variation among themselves despite the significant difference in shoot morphology.
[Pubmed: 20579272]
| | 22. |
1985 Mar |
[Structure of the mammillary bodies of the hypothalamus of the bottlenosed dolphin].
Kalinina AV, Khimina GA, Ul'ianov MIu, Biriukova MA
Arkh Anat Gistol Embriol. 1985 Mar;88(3):34-9.
Abstract
In the bottlenosed dolphin (Tursiops truncatus) the hypothalamic corpus mammillaris has been studied using interperpendicular, sagittal, frontal and horizontal serial sections, impregnated in silver and stained with cresil-violet. Comparatively small dimentions of the corpora mammillaria in the bottlenosed dolphin are explained by presence of only two nuclei, medial and lateral. The lateral nucleus is nearly three times as large as the medial one. The size of the neurons in the medial nucleus is on the average two times as large as that of neurons in the lateral nucleus. The density of the neural cells distribution is a little greater in the lateral nucleus. The structure of the bottlenosed dolphin corpora mammillaria is compared with similar structures in other animals and the human being.
[Pubmed: 3924008]
| | 23. |
1981 |
[Juvenile type of subacute necrotizing encephalomyelinopathy (Leigh) with unusual CNS-localisation].
Lahl R
Acta Neuropathol. 1981;55(3):237-42.
Abstract
The case of an adolescent girl aged 16 with subacute necrotizing encephalomyelopathy (Leigh) is reported. The chronic course of illness lasting for 7.5 years was characterized by visual and gait disorders progressing to blindness, incomplete spastic tetraparesis, and fatal respiratory insufficiency. Neuropathology, in addition to CNS lesions with typical pattern, revealed involvement of Ammon's horn, fornix, corpora mammillaria, tractus mammillothalamicus, and corpus callosum. The massive damage to the total Ammon's horn formation, the distribution of which correlates to none of the established patterns of lesion, is related to the primary disease given, and an additional secondary transneuronal degeneration of associated systems is suggested.
[Pubmed: 6818822]
| | 24. |
1969 Jan |
[Several characteristics of the ultrastructure of the mammillary body (corpora mammillaria) of the brain].
Mikeladze AL, Lazriev IL
Arkh Anat Gistol Embriol. 1969 Jan;56(1):28-34.
[Pubmed: 5810026]
| | 25. |
2011 Mar 29 |
Endophytic bacteria of Mammillaria fraileana, an endemic rock-colonizing cactus of the southern Sonoran Desert.
Lopez BR, Bashan Y, Bacilio M
Arch. Microbiol. 2011 Jul;193(7):527-41. Epub 2011 Mar 29.
Abstract
The small cactus Mammillaria fraileana is a pioneer rock-colonizing plant harboring endophytic bacteria with the potential for nitrogen fixation and rock weathering (phosphate solubilization and rock degradation). In seeds, only a combination of culture-independent methods, such as fluorescence in situ hybridization, scanning electron microscopy, and fluorescence vital staining, detected significant amounts of non-culturable, but living, endophytic bacteria distributed underneath the membrane covering the embryo, in the undifferentiated tissue of the embryo, and in the vascular tissue. Large populations of culturable endophytic bacteria were detected in stems and roots of wild plants colonizing rocks in the southern Sonoran Desert, but not in seeds. Among 14 endophytic bacterial isolates found in roots, four isolates were identified by full sequencing of their 16S rRNA gene. In vitro tests indicated that Azotobacter vinelandii M2Per is a potent nitrogen fixer. Solubilization of inorganic phosphate was exhibited by Pseudomonas putida M5TSA, Enterobacter sakazakii M2PFe, and Bacillus megaterium M1PCa, while A. vinelandii M2Per, P. putida M5TSA, and B. megaterium M1PCa weathered rock by reducing the size of rock particles, probably by changing the pH of the liquid media. Cultivated seedlings of M. fraileana, derived from disinfected seeds and inoculated with endophytic bacteria, showed re-colonization 105 days after inoculation. Their densities decreased from the root toward the stem and apical zones. Functional traits in planta of culturable and non-culturable endophytic bacteria in seeds remain unknown.
[Pubmed: 21445557]
| | 26. |
2009 Feb |
The adaptive value of cued seed dispersal in desert plants: Seed retention and release in Mammillaria pectinifera (Cactaceae), a small globose cactus.
Peters EM, Martorell C, Ezcurra E
Am. J. Bot. 2009 Feb;96(2):537-41.
Abstract
Serotiny, or delayed seed dispersal, is common in fluctuating environments because it hedges the risks of establishment. Mammillaria pectinifera (Cactaceae) facultatively expels fruits in the year they are produced or retains them to disperse the seed over several years. We tested whether M. pectinifera increased fruit expulsion as a response to increased rainfall. While no fruit expulsion was observed in 1997, a dry year, in the wetter 1998 around 20% of all fruits formed were expelled from the maternal plant. A greenhouse experiment showed that high moisture results in the plants expelling all their fruits. Because in 1998 establishment was five times higher than in 1997, this response seems to be highly adaptive: Active fruit expulsion and consequent seed release increases the probability of establishment during pulses of high precipitation.
[Pubmed: 21628209]
| | 27. |
2008 Oct 13 |
Isolation, characterization and cross-amplification of polymorphic microsatellite loci in the threatened endemic Mammillaria crucigera (Cactaceae).
Solórzano S, Cortés-Palomec AC, Ibarra A, Dávila P, Oyama K
Mol Ecol Resour. 2009 Jan;9(1):156-8. Epub 2008 Oct 13.
Abstract
The cactus Mammillaria crucigera is a threatened species endemic to central Mexico. As a means of assessing population genetic status of these species, eight microsatellite markers were developed. These primers were tested in 40 individual from two wild populations. The results showed that these primers will be useful to describe population structure and aid to the conservation of species. The eight primers were tested in other Mammillaria species and most of them showed successful amplification.
[Pubmed: 21564589]
| | 28. |
2004 Jul |
Phylogenetic studies of Mammillaria (Cactaceae)--insights from chloroplast sequence variation and hypothesis testing using the parametric bootstrap.
Butterworth CA, Wallace RS
Am. J. Bot. 2004 Jul;91(7):1086-98.
Abstract
The genus Mammillaria is likely the most species-rich and morphologically variable genus in the Cactaceae. There is doubt as to whether the genus is monophyletic, and past infrageneric treatments differ regarding generic circumscription. Phylogenetic questions about Mammillaria were addressed using chloroplast DNA sequence data from the rpl16 intron and the psbA-trnH intergenic spacer for 125 taxa (113 Mammillaria, 10 Coryphantha, Escobaria, Neolloydia, Pelecyphora, Ortegocactus, and two outgroup taxa from Ferocactus and Stenocactus). Parsimony analyses were conducted using various heuristic search strategies. Bayesian analyses were conducted using the F81 and F81 + I + G models of sequence evolution. Tree topologies from the parsimony and Bayesian analyses were largely congruent. Hypothesis testing was undertaken using the parametric bootstrap to test the monophyly of the genus and the taxonomic status of Mammillaria candida. Phylogenies derived from the parsimony and Bayesian analyses indicate that Mammillaria is not monophyletic and that the genus Mammilloydia (synonym Mammillaria) is embedded within a "core" group of Mammillaria species. Both these results were corroborated by the parametric bootstrap tests. The entire rpl16 intron was deleted from species in the Mammillaria crinita group.
[Pubmed: 21653464]
| | 29. |
2012 Feb 4 |
Bacterial community structure in the rhizosphere of three cactus species from semi-arid highlands in central Mexico.
Aguirre-Garrido JF, Montiel-Lugo D, Hernández-Rodríguez C, Torres-Cortes G, Millán V, Toro N, Martínez-Abarca F, Ramírez-Saad HC
Antonie Van Leeuwenhoek. 2012 Feb 4; [Epub ahead of print]
Abstract
The nature reserve of Tehuacan-Cuicatlan in central Mexico is known for its diversity and endemism mainly in cactus plants. Although the xerophytic flora is reasonably documented, the bacterial communities associated with these species have been largely neglected. We assessed the diversity and composition of bacterial communities in bulk (non-rhizospheric) soil and the rhizosphere of three cactus plant species: Mammillaria carnea, Opuntia pilifera and Stenocereus stellatus, approached using cultivation and molecular techniques, considering the possible effect of dry and rainy seasons. Cultivation-dependent methods were focused on putative N(2)-fixers and heterotrophic aerobic bacteria, in the two media tested the values obtained for dry season samples grouped together regardless of the sample type (rhizospheric or non-rhizospheric), these groups also included the non-rhizospheric sample for rainy season, on each medium. These CFU values were smaller and significantly different from those obtained on rhizospheric samples from rainy season. Genera composition among isolates of the rhizospheric samples was very similar for each season, the most abundant taxa being α-Proteobacteria, Actinobacteria and Firmicutes. Interestingly, the genus Ochrobactrum was highly represented among rhizospheric samples, when cultured in N-free medium. The structure of the bacterial communities was approached with molecular techniques targeting partial 16S rRNA sequences such as denaturing gradient gel electrophoresis and serial analysis of ribosomal sequence tags. Under these approaches, the most represented bacterial phyla were Actinobacteria, Proteobacteria and Acidobacteria. The first two were also highly represented when using isolation techniques.
[Pubmed: 22307841]
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