Founder effect in 20 Afrikaner kindreds with pseudoxanthoma elasticum

The pedigrees of 20 families with pseudoxanthoma elasticum (PXE) were investigated. The analyses involved 13 generations up to and including the initial settlers, who arrived in the Cape before 1660. Four settler surnames predominate in these pedigrees. Because of the marriage patterns of the settlers' descendants it was necessary to classify the four surnames Into two groups. It is suggested that these two groups are the founder groups of present-day PXE patients. Similar genealogical studies have been performed on kindreds with familial polyposis, familial heart block and familial hyper. cholesterolaemia, among other disorders. Due to geographical isolation, political developments and cultural factors in the Afrikaner, these investigations are feasible and often lead to the identification of founder origin

Effect of oral fructose on ethanol elimination from the bloodstream

Alcohol has been identified as a major factor contributing to traffic accidents in South Africa, affecting both drivers and pedestrians alike. An agent capable of facilitating ethanol metabolism safely and effectively is of potential value in reducing the frequency of such incidents, and for individuals wishing to reduce their blood alcohol to levels below the legal limit before taking control of a vehicle. Here we show that fructose, at a dose of 1 g/kg, fulfils the criteria for such an agent. When ingested by healthy volunteers who had imbibed ethanol equivalent to 8 standard tots, it reduced the time required to attain a legal blood alcohol level (50 mg%) by approximately 70 min (n = 9). When ingested before a dose of alcohol equivalent to a double tot, fructose reduced both the magnitude and duration of the subsequent increase in blood alcohol; mean peak height, area under the curve, and time taken to reach zero were 39%, 32% and 51%, respectively, of that observed in the absence of fructose (n = 12). We conclude that, whether taken after imbibing alcoholic beverages or prophylactically before commencing drinking, oral fructose significantly lowers blood alcohol levels and reduces the time required for alcohol to disappear from the bloodstream

Leaching of phthalate acid esters from plastic mulch films and their degradation in response to UV irradiation and contrasting soil conditions

Phthalate acid esters (PAEs) are commonly used plastic additives, not chemically bound to the plastic that migrate into surrounding environments, posing a threat to environmental and human health. Dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) are two common PAEs found in agricultural soils, where degradation is attributed to microbial decomposition. Yet the impact of the plastic matrix on PAE degradation rates is poorly understood. Using 14C-labelled DBP and DEHP we show that migration from the plastic matrix into soil represents a key rate limiting step in their bioavailability and subsequent degradation. Incorporating PAEs into plastic film decreased their degradation in soil, DBP (DEHP) from 79% to 21% (9% to <1%), over four months when compared to direct application of PAEs. Mimicking surface soil conditions, we demonstrated that exposure to ultraviolet radiation accelerated PAE mineralisation twofold. Turnover of PAE was promoted by the addition of biosolids, while the presence of plants and other organic residues failed to promote degradation. We conclude that PAEs persist in soil for longer than previously thought due to physical trapping within the plastic matrix, suggesting PAEs released from plastics over very long time periods lead to increasing levels of contamination

Differential gene expression in East African highland bananas (Musa spp.): interactions between nonpathogenic Fusarium V5w2 and Radopholus similis

Endophytic non-pathogenic Fusarium oxysporum isolates are known to control Radopholus similis through induced resistance. Using complementary (c)DNA-amplified fragment length polymorphism (cDNA-AFLP), we identified genes induced in nematode-susceptible and -tolerant bananas following colonization by non-pathogenic endophytic F. oxysporum isolate V5w2. Quantitative real-time polymerase chain reactions (qRT-PCR) were then used to analyze expression profiles of selected genes. Accumulated gene transcripts included those involved in signal transduction, cell wall strengthening, Jasmonic acid (JA) pathway and transport of defense molecules. Endophyte colonization primed the expression of b-1,3-glucan synthase and Coronatine insensitive 1 (COI1) in the susceptible cultivar, and that of COI1 and Lipoxygenase (LOX) in the tolerant.We isolate and identify for the first time genes involved in the interaction between endophytic non-pathogenic F. oxysporum and banana

Defenserelated gene expression in susceptible and tolerant bananas (Musa spp.) following inoculation with nonpathogenic Fusarium oxysporum endophytes and challenge with Radopholus similis

Radopholus similisis a major pest of East African highland cooking bananas (Musaspp.) in Uganda. Non-pathogenic Fusariumoxysporumendophytes, isolated from bananas in farmers’ fields, have shown potential to reduceR. Similis numbers in tissue culture banana. The mechanism through which endophytes confer resistance to nematodes has previously been demonstrated to involve inducedresistance. In this study, the expression of eight defense-related genes in banana was investigated using quantitative real-time reverse transcription PCR. Plants of susceptible (cv. Nabusa, genomic group AAA-EA) and tolerant (cv. Kayinja, genomic group ABB) banana cultivars were inoculated with endophyticF. Oxysporum strain V5w2. Gene expression levels were analysed following endophyte inoculation and nematode challenge. Endophyte colonization of roots of the tolerant cultivar induced transient expression of POX and suppressed expression ofPR-3,lectin, PAE, PALandPIR7A. CatalaseandPR-1activities were up-regulated in the tolerant cultivar 33days after endophyte colonization of roots, but their expressions were further up-regulated following nematode challenge. Apart from POX andlectin, the other genes analysed were not responsive to endophyte colonization orR. Similis challenge in the susceptible cv.Nabusa. This is the first report of endophyte-induced defense-related gene expression in banana

Dual inoculation of Fusarium oxysporum endophytes in banana: effect on plant colonization, growth and control of the root burrowing nematode and the banana weevil

The burrowing nematode (Radopholus similis (Cobb) Thorne) and the banana weevil (Cosmopolites sordidus Germar, Coleoptera: Curculionidae) are major pests of banana (Musa spp.) in the Lake Victoria basin region of Uganda. Among biological options to control the two pests is the use of non-pathogenic Fusarium oxysporum Schltdl.: Fries endophytes of banana. We investigated the ability of endophytic F. oxysporum isolates Emb2.4o and V5w2 to control the banana weevil and the burrowing nematode, alone and in combination. Plant colonization by the endophytes was determined by inoculating their chemical-resistant mutants separately and in combination, onto banana roots. Plant growth promotion was determined by measuring plant height, girth, number of live roots and fresh root weight at harvest, and control of the nematode and weevil was determined by challenging endophyte-inoculated plants with the pests 8 weeks after endophyte inoculation. Endophytic root colonization was highest in plants inoculated with both endophytes, compared with those inoculated with only one of the endophytes. Root colonization was better for isolate V5w2 than Emb2.4o. Dually inoculated plants showed a significant increase in height, girth, fresh root weight and number of functional roots following nematode challenge. Nematode numbers in roots were reduced 12 weeks after challenge of 8-week-old endophyte-inoculated plants. Significant reductions in weevil damage were observed in the rhizome periphery, inner and outer rhizomes, compared with endophyte non-inoculated controls. We conclude that dual inoculation of bananas with endophytic isolates Emb2.4o and V5w2 increases root colonization by the endophytes, reduces nematode numbers and weevil damage, and enhances plant growth in the presence of nematode infestation

Effect of dual endophyte inoculations on plant colonization, and control of Radopholus similis and the banana weevil

The root burrowing nematode Radopholus similis and the banana weevil Cosmopolites sordidus are major pests of banana in the Lake Victoria basin region. An integrated pest management approach that includes habitat management, biological control, host plant resistance and chemical control is currently used to control populations of the two pests. Biological control strategies with potential to control the banana weevil and R. similis include the use of entomopathogenic fungi Beauveria bassiana and non-pathogenic Fusarium oxysporum endophytes of banana. The current study was designed to investigate the effect of dual endophyte inoculations on control of the two pests in ‘Nabusa’ ( spp., AAA-EA group). Endophytic F. oxysporum isolate V5w2 known to reduce R. similis numbers in screenhouse pot trials was inoculated together with isolate Emb2.4o, known to be effective against the banana weevil. Root and rhizome colonization was higher

Efficacy of chemical and flourescent protein markers in studying plant colonization by endophytic nonpathogenic Fusarium oxysporum isolates

In studying plant colonization by inoculated Fusarium oxysporum endophytes, it is important to be able to distinguish inoculated isolates from saprophytic strains. In the current study, F. oxysporum isolates were transformed with the green (GFP) and red fluorescent protein (DsRed) genes, and benomyl- and chlorate-resistant mutant isolates were also developed. The benomyl- and chlorate-resistant mutants, and the fluorescently labelled transformants, were able to grow on potato dextrose agar amended with 20 mg Benlate® l−1, 30 g chlorate l−1 and 150 μg hygromycin ml−1, respectively. Single spores of all mutants remained stable after several transfers on non-selective media. Most mutants and transformants produced colony diameters that did not differ significantly from that of their wild-type progenitors after 7 days of growth on non-selective media. Few mutants, however, had growth rates that were either slower or faster than for their wild-types. Plant colonization studies showed that root and rhizome tissue colonization by most benomyl- and chlorate-resistant mutants was similar to that of their wild-type isolates. Unlike GFP transformants, DsRed transformants were difficult to visualize in planta. Both the mutants and transformants can be used for future studies to investigate colonization, distribution and survival of biocontrol F. oxysporum endophytes in banana plants

Banana diseases and pests: field guide for diagnostics and data collection

Improvement of banana for smallholder farmers in the Great Lakes Region of Africa This unique project seeks to improve the production and productivity of banana in Tanzania and Uganda, through the development of hybrid banana varieties that are expected to have 30% higher yield compared to the current varieties grown by farmers under the same conditions through improved resistance against key pests and diseases. In particular, the project will strengthen the banana breeding programs in the two countries, towards developing new high-yielding and disease-resistant hybrid banana varieties, primarily focusing on the two most popular cooking bananas in the region: East Africa highland banana (EAHB), also known as Matooke, and on Mchare