The effect of administration of methanol extract of T. orientalis leaf on liver function parameters and histology of cadmium induced toxicity in Wistar rats was investigated. In the study, 125 male ...Wistar albino rats weighing 180 ± 10.00 g were randomly grouped into 5 groups (A - E) with twenty-five (25) rats in each group. Group A rats were administered distilled water and feed only and served as control. Group B rats were given oral administration of 10 mg/kg body weight of Cadmium (Cd), while group C rats were administered 100 mg/kg body weight of methanol extract of T. orientalis leaf. Group D and E rats were concurrently given orally, 10 mg/kg body weight of Cd with 100 mg/kg body weight and 200 mg/kg body weight extract respectively. The serum total protein, albumin and bilirubin concentration and the activity of alanine aminotransferase (ALT) were significantly (P < 0.05) decreased in Cd-treated group. Though the concentration of total protein and albumin in serum showed insignificant increase following the immediate co- administration of Cd and the extract, further administration up to the final day resulted in significant (P < 0.05) increased in these parameters. The activity of the serum ALT significantly increased following co-treatment with Cd and the leaves extract. Also the serum concentration of total and conjugated bilirubin were significantly (P < 0.05) decreased on co-administration of Cd and the extract when compared with the Cd administration. Histological examination revealed congestion of the group hepatic venule, with blood cells in the hepatocytes accompanied with hypercellularity and diffused cellular balloon. Also there was degeneration and necrosis of hepatic cells in the Cd group. In contrast, the administration of the leaves extract to rats reversed the adverse effect of Cd to the rats. Continuous administration of the plant extract alone caused a mild toxicity in rats liver tissues. This is an indication that dose regulation is critical to monitoring the T. orientalis therapy. Relatively, the plant extract demonstrated a reasonable level of ability to alleviate the risk of Cd toxicity in rats.
Agriculture was introduced into the Central African rainforest from the drier West African savanna, in concert with a major climatic change that amplified seasonality just after 2500 BP. The savanna ...crop pearl millet (Pennisetum glaucum), dated to 2400–2200 BP, could only be cultivated due to the development of a distinct dry season. Increasing seasonality and the replacement of mature forests by pioneer formations is indicated by Trema orientalis in the pollen diagram of Nyabessan after 2400 BP. However, charcoal data do not point to the existence of savannas in South Cameroon during this period, but rather to a mosaic of mature and pioneer forests. The early rainforest farmers combined the cultivation of pearl millet with the exploitation of wild oil-containing tree fruits, such as oil palm and Canarium. The existence of pioneer formations that can be easily cut favoured the establishment of shifting cultivation. The archaeobotanical finds fit into a linguistic scenario of West-Bantu speakers making the cultivation of pearl millet one of their food production strategies before expanding further to the South. The reconstructed inherited pearl millet vocabulary for the early phases of Bantu language history provides strong circumstantial evidence for an overlap of the major stages of the Bantu expansion with the dispersal of food production.
All plants contain hemoglobins that fall into distinct phylogenetic classes. The subset of plants that carry out symbiotic nitrogen fixation expresses hemoglobins that scavenge and transport oxygen ...to bacterial symbiotes within root nodules. These "symbiotic" oxygen transport hemoglobins are distinct in structure and function from the nonoxygen transport ("nonsymbiotic") Hbs found in all plants. Hemoglobins found in two closely related plants present a paradox concerning hemoglobin structure and function. Parasponia andersonii is a nitrogen-fixing plant that expresses a symbiotic hemoglobin (ParaHb) characteristic of oxygen transport hemoglobins in having a pentacoordinate ferrous heme iron, moderate oxygen affinity, and a relatively rapid oxygen dissociation rate constant. A close relative that does not fix nitrogen, Trema tomentosa, expresses hemoglobin (TremaHb) sharing 93% amino acid identity to ParaHb, but its phylogeny predicts a typical nonsymbiotic hemoglobin with a hexacoordinate heme iron, high oxygen affinity, and slow oxygen dissociation rate constant. Here we characterize heme coordination and oxygen binding in TremaHb and ParaHb to investigate whether or not two hemoglobins with such high sequence similarity are actually so different in functional behavior. Our results indicate that the two proteins resemble nonsymbiotic hemoglobins in the ferric oxidation state and symbiotic hemoglobins in the ferrous oxidation state. They differ from each other only in oxygen affinity and oxygen dissociation rate constants, two factors key to their different functions. These results demonstrate distinct mechanisms for convergent evolution of oxygen transport in different phylogenetic classes of plant hemoglobins.
Volcanic eruptions disturb vegetation at a time it is needed for preventing mudflows. A resilient indigenous non-legume nitrogen-fixing tree that is adapted to the ash and spreads rapidly protects ...areas downstream in a volcanic landscape in Indonesia. Within the volcanic ring of fire both the long-term benefits (including densely populated, fertile agricultural soils) and short-term ecological disturbance of volcanic ash deposition are clear. Mount Kelud in East Java has erupted on a 15–37-years cycle for the past centuries, most recently in 2014, causing damage to settlements, agricultural land, agroforestry, and watershed protection forests, as the ash deposits caused tree mortality, restricted infiltration, and led to ash flows. Rapid “restoration” or recovery of tree-based vegetation with planted Legume trees (such as
Calliandra
spp.) has been attempted but is not very effective. However, the non-legume nitrogen-fixing
Parasponia rigida
, symbiotic with rhizobium bacteria, contrasted to its non-symbiotic sibling
(Trema orientalis)
has been studied in laboratory conditions, but not in its native environment. We mapped and sampled
P. rigida
in various locations (upper, middle, and lower elevation positions in ridge-slope-valley toposequences) on the Kelud complex starting 1 year after the latest eruption, estimated biomass development, and quantified
P. rigida
root nodules in relation to N availability in the ash/soil mixtures in these locations.
P. rigida
was found as a pioneer tree at elevations between 600 and 1,700 m a.s.l. (above sea level) along ridges, in slope, and valley positions. At lower elevations
T. orientalis
dominated. Within 3 years of the eruption, stem diameters were 3–10 cm. Up to 93% of
P. rigida
root nodules were found to be effective, based on the hemoglobin color on cross-sections.
Rhizobium
bacteria were found in root nodule tissue at densities of two to a hundred times higher than in rhizosphere soil. Between a total soil N content from 0.01 to 0.04% the density of effective nodules decreased from 1,200 to 200 m
−2
.
P. rigida
stands in the area, especially at ridges close to the crater deserve to be managed proactively as future seed sources, given the high frequency of eruption episodes, while recovery after eruptions on similar volcanoes can likely be facilitated by tactical assisted seed dispersal if effective seed collection and storage methods can be established.
The pathogens associated with citrus Huanglongbing symptoms, including yellowing and mottled leaves in Citrus maxima, an important economic crop on Hainan Island of China, were identified and ...characterized. In the study, detection, genetic variation and phylogenetic relationship analysis of the pathogens were performed based on 16S rRNA and β-operon gene fragments specific to phytoplasma and Candidatus Liberibacter asiaticus. The results indicated that the pathogens—such as phytoplasma strains of CmPII-hn belonging to the 16SrII-V subgroup and CmPXXXII-hn belonging to the 16SrXXXII-D subgroup, as well as Candidatus Liberibacter asiaticus strains CmLas-hn—were identified in the diseased plant samples, with numbers of 12, 2 and 6 out of 54, respectively. Among them, mixed infection with the 16SrII-V subgroup phytoplasma and Candidatus Liberibacter asiaticus was found in the study, accounting for 7.4% (four samples). The phytoplasma strains of CmPII-hn—Tephrosia purpurea witches’ broom, Melochia corchorifolia witches’ broom and Emilia sonchifolia witches’ broom—were clustered into one clade belonging to the 16SrII-V subgroup, with a 99% bootstrap value. The phytoplasma strains of CmPXXXII-hn and Trema tomentosa witches’ broom belonging to 16SrXXXII-D, and the other 16SrXXXII subgroup strains were clustered into one clade belonging to the 16SrXXXII group with a 99% bootstrap value. There were 16 variable loci in the 16S rRNA gene sequences of the tested 16SrXXXII group phytoplasma strains, of which two bases had an insertion/deletion. The strains of Candidatus Liberibacter asiaticus, identified in the study and the strains that had been deposited in GenBank, were in one independent cluster with a 99% bootstrap value. To our knowledge, this is the first report showing that Citrus maxima can be infected by 16SrII-V and16SrXXXII-D subgroup phytoplasmas in China. Moreover, this is also the first report in which the plants are co-infected by 16SrII-V subgroup phytoplasmas and Candidatus Liberibacter asiaticus. More comprehensive and detailed identification and characterization of the pathogens associated with the diseased symptoms in Citrus maxima on the island in China would be beneficial for epidemic monitoring and for the effective prevention and control of related plant diseases.
► Pioneers differentiated along disturbance characteristics and canopy light environment. ► Differentiation was observed in all size classes: seedlings, saplings and larger trees. ► Historical ...condition of disturbance was more important than light for larger trees. ► Disturbance type predicted occurrence better than history and intensity in juvenile plants. ► Conclusion: to restore or reforest, pioneers should be matched carefully to site conditions.
Pioneer tree species of tropical rain forests in the seedling and sapling size classes are generally associated with disturbances to the forest canopy. Pioneers have usually been lumped together within the same broad guild. Many studies have demonstrated differentiation of late successional shade-tolerant species within a forest but only a few studies have shown pioneers to be complex in differentiation. Most assume pioneers to be generalist and similar in growth and establishment. It is therefore not well understood, how sympatric pioneer species differ across life history stages in relation to disturbance characteristics such as canopy openness, type, intensity and historical condition of disturbance. Here we studied seedlings, saplings and larger trees of eight pioneer species common in and around the Sinharaja World Heritage Reserve in Sri Lanka to characterize species differences in relation to canopy openness, type and intensity of disturbance. We analyzed canopy hemispherical photographs and conditions of disturbance and assessed the probability of species’ occurrence and the relative importance of disturbance characteristics by fitting progressively more complex multinomial logistical regression models. Canopy openness demonstrated the greatest association with seedling and sapling distribution. Trema orientalis, was found in the highest light conditions, while all other species showed a decrease in the probability of occurrence with increasing canopy openness. For larger trees, the historical condition of disturbance was shown to be a more important factor than the light characteristics. Irrespective of size classes, T. orientalis and Macaranga peltata were restricted to high light environments and large disturbances whereas Macaranga indica, Dillenia triquetra, Schumacheria castaneifolia, and Wendlandia bicuspidata were found in relatively lower light environments and smaller disturbances. Alstonia macrophylla and Melastoma malabathricum were able to exist across wide ranging light conditions. In seedlings and saplings, disturbance type was more influential than both the historical condition of disturbance and the intensity of the disturbance, with some evidence that species do occur differentially in certain disturbance types. In summary this study provides evidence that pioneers of all life history stages differentiate in relation to amount of light and disturbance characteristics and that such differentiations are important mechanisms for the coexistence and diversity of early seral tropical tree species. Findings from our study suggests that pioneers used for reforestation and site amelioration need to be selected carefully to match degree of exposure, history and type of disturbance of the site that is to be reforested.
•The facilitation process, unexplored ecological interaction in cloud forests.•In ecological succession, early species generate microenvironments conducive to late species.•The survival of plants in ...degraded areas is a key aspect in restoration.•The facilitation process guidelines we restore the cloud forest.
The loss of primary cloud forest within the original range of this ecosystem is one of the highest worldwide. Facilitation is a process in the plant community dynamics that is potentially useful for the restoration of degraded ecosystems. Secondary cloud forest tree species possess attributes that make them suitable to be used as facilitator species for the establishment of tree species typical of intermediate and late successional stages. In this study we examined the facilitator potential of two early successional species, Alnus acuminata and Trema micrantha, both of which grow rapidly and are capable of gradually modifying physical micro-environmental conditions of open sites where forest was cleared. The aim was to assess the effects of these two species on the survival and growth of two intermediate successional species, Juglans pyriformis and Quercus insignis, and one late successional species, Oreomunnea mexicana. Open sites were used as control. Survivorship of the three target species was significantly higher under the canopies of A. acuminata and T. micrantha compared to open sites. Almost all annual growth rates (cover, diameter and height) were not different in both experiments (under the canopy of A. acuminata and T. micrantha), regarding treatment (under canopy vs. open areas) and species (target species). However, results for target species survival strongly suggest that plantations of early successional species can facilitate the establishment of intermediate and late successional trees, and thus represent a promising strategy for cloud forest restoration.
Purpose: This study aimed to analyze the anatomy and histochemistry of Trema micrantha fruit to correlate the data with its wide distribution in urban areas. Theoretical framework: T. micrantha is ...a native tree species belonging to the Cannabaceae family and grows widely in urban areas, riparian forests, and environmental recovery areas in Brazil. The fruit is of the drupe type and is mainly consumed by avifauna, however, reports on its anatomy and chemical composition are lacking, and the relationship between fruit structure and dispersion syndromes has not been studied. Method: The mature fruits were fixed, dehydrated, embedded, polymerized in methacrylate, and sectioned using a rotating microtome. The slides were mounted, stained, and analyzed under a light microscope. Surface analysis was performed using scanning electron microscopy (SEM). Results and conclusion: The pericarp consisted of an exocarp, a mesocarp, and an endocarp. The exocarp is uniseriate and contained papillae, stomata, and a cuticle. The mesocarp is parenchymatic and subdivided into three regions: external, middle, and internal. The endocarp is uniseriate and contains sclerified cells. Histochemical tests revealed the presence of lipids, proteins, starch grains, phenolic compounds, and alkaloids in the mesocarp. Research implications: The presence of lipids, proteins, and starch increases the nutritional value of the fruit, indicating its dispersion by animals, mainly birds, and the dispersion of diaspores in urban areas. Originality/value: T. micrantha contributes to the food chain of local fauna, and their population will benefit from by increasing afforestation.
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