Chemical quality of common beans as influenced by genotype and aluminium rates under two soil liming regimes

Soil acidity affects seed yield and crop quality negatively due to aluminium toxicity in most humid tropics where the crop is cultivated for food and cash income by smallholder farmers. This study was conducted to assess the effect of different exchangeable aluminium concentrations on bean chemical quality of two common bean genotypes grown on lime-treated and lime-untreated soils. Factorial combinations of five aluminium rates (0.0, 12.5, 25.0, 50.0, and 100.0 mg Al/ kg soil) and two common bean genotypes (New BILFA 58 and Roba 1) were laid out in a completely randomized design with three replications. For each treatment, four plants were raised per pot in the vegetation hall of Nekemte Soil Laboratory, western Ethiopia. The experiment was established in two sets: lime-treated soil and lime-untreated soil. The results revealed that aluminium toxicity caused major changes in the composition of the common beans. Significant differences (P < 0.01) were found among the different aluminium rates and between the two genotypes for bean crude protein, crude fibre, crude fat, and ash, carbohydrate, calcium, magnesium, and aluminium contents under both liming regimes. The interaction of aluminium and genotype also influenced most of the bean chemical quality attributes negatively. New BILFA 58 (acidic soil tolerant genotype) had better bean chemical quality attributes (except aluminium and condensed tannins contents) than Roba 1 (acidic soil sensitive genotype) under both liming regimes. On the average, lime application increased bean crude protein, crude fat, ash, and calcium contents by 4.1%, 20.7%, 7.9%, and 11.7%, respectively. However, it decreased bean crude fibre and aluminium contents. Bean carbohydrate and condensed tannin contents of the genotypes increased in response to increasing aluminium application under both liming regimes. The total ash, which is an indirect indicator of the mineral content of foodstuffs, was found to be higher for New BILFA 58 than Roba 1 under both liming regimes. In conclusion, the results of this study have demonstrated that increased soil aluminium contents have significant negative effects on common bean quality, but integrated use of tolerant genotypes and application of lime can simultaneously alleviate the problem of low yield and reduced bean nutritional quality of the crop.Keywords: Aluminium, proximate, Lime, soil, Phaseolusvulgari

Household Fertilizers Use and Soil Fertility Management Practices in Vegetable Crops Production: The Case of Central Rift Valley of Ethiopia

Large areas of farms are covered by variety of vegetable crops in the Central Rift Valley of Ethiopia. With a view to improve current vegetable production fertilizer use efficiency, survey has been conducted through collections of baseline information to describe household fertilizer uses and soil fertility management in vegetable production system using descriptive statistics. Multistage samplings were made to select  representative growers in the six districts of East Showa zone. Based on field observations and group discussions, vegetable growers grouped their farm land into four local categories. The survey revealed that tomato growers apply variable rates of urea and DAP fertilizers for tomato cultivation. Survey results indicated that highest 43.61% of onion growers apply 200 kg of DAP fertilizer on their onion field, while 30.85% of growers apply 300 kg DAP per ha, another 39.35% apply, 400 kg and above DAPfertilizer, still 8.5% of onion growers apply 600 kg DAP fertilizer on their onion farm. This survey indicated that fertilizers were not wisely used in the vegetable crops production systems and the applications are in excess rate, which could leads to pollution of the environment from over dose application and from runoff in to the water bodies and leaching in to the ground water with economic loss. Most of the tomato and onion growers use three splits application of UREA and DAP mainly at transplanting, at first and second cultivation for both crops as top-dressing. The survey results indicated that 54.44% of onion growers apply an average of 230.35 kg ha-1 DAP at transplanting, while 46.53% apply an average of 188.29kg ha-1 DAP at second split application, and finally 17.82% apply an  average of 119.44 kg ha-1 DAP at last third split applications. This is the first document come across that vegetable growers in the CRV area apply DAP fertilizer as much as three splits. This indicates that there are no  systems of updating of frontline development workers; poor extension services with shallow development workers knowledge made the growers totally depend on their own innovations for vegetable production

Irrigation Water Management Practices in Smallholder Vegetable Crops Production: The Case of the Central Rift Valley of Ethiopia

Smallholder irrigated vegetable production in the Central Rift Valley region of Ethiopia is instrumental in ensuring the year-round availability of fresh vegetables in the local market in the country. However, a number of  problems constrain irrigated vegetable production in the region. Therefore, asurvey was conducted with the objectives of assessing smallholder  irrigated vegetable production practices and identifying factors associated with problems of irrigation water management. The survey was conducted in December 2011. A multistage purposive sampling procedure was  employed to select sample districts, peasant associations, and sample respondents that grew vegetables using small-scale irrigation. Key  informants were interviewed and group discussions were conducted with smallholder vegetable farmers. Data were collected on household irrigation knowledge, experiences, skills, irrigation water sources as well as on  irrigation water management practices such as methods, time, depth and frequency of irrigation. Data were also collected on supplemental irrigation practices under rain-fed vegetable production. In addition, household perceptions on the environmental impacts of irrigation, on-farm irrigation water related challenges, and related information were also recorded. About 16.5% of the respondents indicated that their knowledge and skills on irrigation water management practices were mainly drawn from experiences of trial and error.About 38.1% of the respondents indicated that they  irrigated their vegetable fields both in the morning and the afternoon  whereas 35.1% replied that they irrigated only in the afternoon. A large number of the respondents (89.6%) replied that they determined irrigation intervals based on specific crop needs. About 90.9% of the respondents replied that they applied enough irrigation water up to the point where the water level reached the furrow basin head. The survey result also indicated that 51.7% of the respondents practiced supplemental irrigation when shortage of moisture occurred in the soil during the rainy season as well at the end of the rainy season. One hundred percent of the respondents replied that they faced problems commonly related with the use of  irrigation, namely, soil salinity, waterlogging, soil erosion and degradation, sedimentation, and build-up of pests and diseases. In conclusion, the survey results revealed that extension services on irrigation water  management were almost non-existent, and the smallholder vegetable farmers managed irrigation water merely by intuition.Therefore,  participatory on-farm irrigation research and extension on irrigation water management practices should be formulated to generate appropriate technologies for enhanced and sustainable irrigated vegetable production in the region

Dynamic regulation of glucocorticoid signalling in health and disease

Activation of the glucocorticoid receptor (GR) by endogenous and synthetic glucocorticoids regulates hundreds of genes to control regulatory networks in development, metabolism, cognition and inflammation. Elucidation of the mechanisms that regulate glucocorticoid action has highlighted the dynamic nature of hormone signalling and provides novel insights into genomic glucocorticoid actions. The major factors that regulate GR function include chromatin structure, epigenetics, genetic variation and the pattern of glucocorticoid hormone secretion. We review our current understanding of the mechanisms that contribute to GR signalling and how these contribute to glucocorticoid sensitivity, resistance and side effects

Targeted analysis of four breeds narrows equine Multiple Congenital Ocular Anomalies locus to 208 kilobases

The syndrome Multiple Congenital Ocular Anomalies (MCOA) is the collective name ascribed to heritable congenital eye defects in horses. Individuals homozygous for the disease allele (MCOA phenotype) have a wide range of eye anomalies, while heterozygous horses (Cyst phenotype) predominantly have cysts that originate from the temporal ciliary body, iris, and/or peripheral retina. MCOA syndrome is highly prevalent in the Rocky Mountain Horse but the disease is not limited to this breed. Affected horses most often have a Silver coat color; however, a pleiotropic link between these phenotypes is yet to be proven. Locating and possibly isolating these traits would provide invaluable knowledge to scientists and breeders. This would favor maintenance of a desirable coat color while addressing the health concerns of the affected breeds, and would also provide insight into the genetic basis of the disease. Identical-by-descent mapping was used to narrow the previous 4.6-Mb region to a 264-kb interval for the MCOA locus. One haplotype common to four breeds showed complete association to the disease (Cyst phenotype, n = 246; MCOA phenotype, n = 83). Candidate genes from the interval, SMARCC2 and IKZF4, were screened for polymorphisms and genotyped, and segregation analysis allowed the MCOA syndrome region to be shortened to 208 kb. This interval also harbors PMEL17, the gene causative for Silver coat color. However, by shortening the MCOA locus by a factor of 20, 176 other genes have been unlinked from the disease and only 15 genes remain

The CRE1 carbon catabolite repressor of the fungus Trichoderma reesei: a master regulator of carbon assimilation

<p>Abstract</p> <p>Background</p> <p>The identification and characterization of the transcriptional regulatory networks governing the physiology and adaptation of microbial cells is a key step in understanding their behaviour. One such wide-domain regulatory circuit, essential to all cells, is carbon catabolite repression (CCR): it allows the cell to prefer some carbon sources, whose assimilation is of high nutritional value, over less profitable ones. In lower multicellular fungi, the C2H2 zinc finger CreA/CRE1 protein has been shown to act as the transcriptional repressor in this process. However, the complete list of its gene targets is not known.</p> <p>Results</p> <p>Here, we deciphered the CRE1 regulatory range in the model cellulose and hemicellulose-degrading fungus <it>Trichoderma reesei </it>(anamorph of <it>Hypocrea jecorina</it>) by profiling transcription in a wild-type and a delta-<it>cre1 </it>mutant strain on glucose at constant growth rates known to repress and de-repress CCR-affected genes. Analysis of genome-wide microarrays reveals 2.8% of transcripts whose expression was regulated in at least one of the four experimental conditions: 47.3% of which were repressed by CRE1, whereas 29.0% were actually induced by CRE1, and 17.2% only affected by the growth rate but CRE1 independent. Among CRE1 repressed transcripts, genes encoding unknown proteins and transport proteins were overrepresented. In addition, we found CRE1-repression of nitrogenous substances uptake, components of chromatin remodeling and the transcriptional mediator complex, as well as developmental processes.</p> <p>Conclusions</p> <p>Our study provides the first global insight into the molecular physiological response of a multicellular fungus to carbon catabolite regulation and identifies several not yet known targets in a growth-controlled environment.</p

Histone H3 Localizes to the Centromeric DNA in Budding Yeast

During cell division, segregation of sister chromatids to daughter cells is achieved by the poleward pulling force of microtubules, which attach to the chromatids by means of a multiprotein complex, the kinetochore. Kinetochores assemble at the centromeric DNA organized by specialized centromeric nucleosomes. In contrast to other eukaryotes, which typically have large repetitive centromeric regions, budding yeast CEN DNA is defined by a 125 bp sequence and assembles a single centromeric nucleosome. In budding yeast, as well as in other eukaryotes, the Cse4 histone variant (known in vertebrates as CENP-A) is believed to substitute for histone H3 at the centromeric nucleosome. However, the exact composition of the CEN nucleosome remains a subject of debate. We report the use of a novel ChIP approach to reveal the composition of the centromeric nucleosome and its localization on CEN DNA in budding yeast. Surprisingly, we observed a strong interaction of H3, as well as Cse4, H4, H2A, and H2B, but not histone chaperone Scm3 (HJURP in human) with the centromeric DNA. H3 localizes to centromeric DNA at all stages of the cell cycle. Using a sequential ChIP approach, we could demonstrate the co-occupancy of H3 and Cse4 at the CEN DNA. Our results favor a H3-Cse4 heterotypic octamer at the budding yeast centromere. Whether or not our model is correct, any future model will have to account for the stable association of histone H3 with the centromeric DNA

The YEATS domain of Taf14 in Saccharomyces cerevisiae has a negative impact on cell growth

The role of a highly conserved YEATS protein motif is explored in the context of the Taf14 protein of Saccharomyces cerevisiae. In S. cerevisiae, Taf14 is a protein physically associated with many critical multisubunit complexes including the general transcription factors TFIID and TFIIF, the chromatin remodeling complexes SWI/SNF, Ino80 and RSC, Mediator and the histone modification enzyme NuA3. Taf14 is a member of the YEATS superfamily, conserved from bacteria to eukaryotes and thought to have a transcription stimulatory activity. However, besides its ubiquitous presence and its links with transcription, little is known about Taf14’s role in the nucleus. We use structure–function and mutational analysis to study the function of Taf14 and its well conserved N-terminal YEATS domain. We show here that the YEATS domain is not necessary for Taf14’s association with these transcription and chromatin remodeling complexes, and that its presence in these complexes is dependent only on its C-terminal domain. Our results also indicate that Taf14’s YEATS domain is not necessary for complementing the synthetic lethality between TAF14 and the general transcription factor TFIIS (encoded by DST1). Furthermore, we present evidence that the YEATS domain of Taf14 has a negative impact on cell growth: its absence enables cells to grow better than wild-type cells under stress conditions, like the microtubule destabilizing drug benomyl. Moreover, cells expressing solely the YEATS domain grow worser than cells expressing any other Taf14 construct tested, including the deletion mutant. Thus, this highly conserved domain should be considered part of a negative regulatory loop in cell growth

SS18 Together with Animal-Specific Factors Defines Human BAF-Type SWI/SNF Complexes

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