10 research outputs found
Ascertaining of Optimum Pyrolysis Conditions in Producing Refuse Tea Biochar as a Soil Amendment
No full textAbstractRefused tea is a waste product of tea processing. Manufacturing of biochar from organic waste is an emerging technology where biochar can be used as a soil amendment for environmental remediation and carbon sequestration. As such the aim of this study was to determine the optimum pyrolysis conditions in producing refuse tea biochar for the said uses. Three refused tea samples were collected randomly from the bulk from tea processing factory in Gampola area of Sri Lanka and basic physical and proximate analysis were done. Initially, refused tea was packed tightly in the pyrolytic reactor which was designed to pyrolysis refused tea and pyrolysis was carried out by using five combinations of temperature (300, 350, 400, 450, 500 oC) and four retention times (15min, 30min, 45min and 1 hour). The physical and chemical characteristics of biochar were analysed in line with the biochar quality standards proposed by International Biochar Initiatives (IBI). Results showed that the yield of biochar varied with the residence time for a given temperature treatment. The chemical, physical and morphological properties of biochar are largely influenced by the residence time for a given temperature treatment. Temperatures between 450oC and 500oC, and residence time between 45 and 60minutes showed the highest biochar mass recovery. This research revealed that refuse tea can be effectively converted to biochar between 450 to 500 oC temperatures subjected to a residence time of 45 to 60minutes. It also showed that higher volatilization rates at optimum temperature and residence time combination can be positively used for up scaling the pyrolysis reactor
Soil Carbon Sequestration and Nutrient Status of Different Landuse Types in Knuckles Mountain Range, Sri Lanka
No full textCarbon can be stored in carbon pools for long periods of time through carbon sequestration.Vegetation, soil, ocean and atmosphere are the main sinks for storage of carbon. Amongthem, soil is a significant C sink that absorbs more C than the others. This study aimed atassessing the potential of soil carbon sequestration in selected landuse types in the Knucklesmountain range, where a variety of climatic conditions and landuse types exist. Montaneforests (MF), sub-montane forests (SMF), open and sparse forests (OSF) and grasslands (GL)were selected for the study. In addition to C sequestration, the soil nutrient levels of theselanduse types were also assessed. Soil samples were collected from each landuse type fromtwo depths (0-15 cm and 15-30 cm) and analysed for soil moisture content, soil pH andconductivity, bulk density, total organic carbon (TOC), microbial biomass carbon (MBC),labile carbon (LC), water soluble carbon (WSC) and soil available macro nutrients (NO3-,NH4+,K,Ca,Mg). Results showed that TOC content was significantly highest in MF andlowest in OSF and GL. The montane forests also recorded higher MBC, LC and WSCcontents (0.14%, 715.2 mg/kg, 0.46% respectively) compared to other studied landuse types.Open and Sparse forests showed the highest NO3- level (0.89 mg/kg) and the highest NH4+level (5.79×10-5 mg/kg) was recorded in MF. The lowest levels of NO3- and NH4+ (0.3 mg/kgand 2.6×10-5 mg/kg) were recorded in GL and OSF respectively. Both Ca and Mg contentswere significantly high in MF. Soil C stocks varied significantly (p<0.05) among theselanduse types, where MF recorded the highest soil C stock of 126.7 t/ha in top soil layer (0-15 cm). Carbon stocks of other three vegetation types SM, OS and GL were 122.4, 98.5 and99.1 t/ha, respectively. The results showed that MF and SM forests have the greater ability ofsequestering C compared to other studied landuse types in the Knuckles mountain range.Keywords: Soil carbon sequestration, Carbon stocks, Nutrients, Knuckles fores
Integrating Indicators in Agricultural Vulnerability Assessment to Climate Change
No full textAbstract
Climate change stands as one of the most pressing challenges confronting global ecosystems and human livelihoods. The agriculture sector of Anuradhapura district, Sri Lanka, well renowned for its pivotal role in the nation’s food production, faces an increasing threat from the changing climate. This study aims to incorporate the indicator system method which uses a set of indicators to assess the agricultural vulnerability (AV) to climate change in Anuradhapura district. The AV assessment used in this study involves three principal components exposure, sensitivity, and adaptive capacity. The indicators are normalized to allow spatial analysis and smooth integration within a geographic information system (GIS) framework. The AV of Anuradhapura district ranged from 0.32 to 0.67 and was divided among five levels very low, low, moderate, high, and very high. The findings suggest that Anuradhapura’s agricultural sector was significantly impacted by climate change as the majority of the total area was found to have very high, high, and moderate levels of AV with 25, 28, and 24%, respectively. The results obtained from this study are essential for formulating plans to improve Anuradhapura’s agricultural sector resilience and adaptability to ensure food security and livelihood sustainability considering the ever-changing climate.Abstract
Climate change stands as one of the most pressing challenges confronting global ecosystems and human livelihoods. The agriculture sector of Anuradhapura district, Sri Lanka, well renowned for its pivotal role in the nation’s food production, faces an increasing threat from the changing climate. This study aims to incorporate the indicator system method which uses a set of indicators to assess the agricultural vulnerability (AV) to climate change in Anuradhapura district. The AV assessment used in this study involves three principal components exposure, sensitivity, and adaptive capacity. The indicators are normalized to allow spatial analysis and smooth integration within a geographic information system (GIS) framework. The AV of Anuradhapura district ranged from 0.32 to 0.67 and was divided among five levels very low, low, moderate, high, and very high. The findings suggest that Anuradhapura’s agricultural sector was significantly impacted by climate change as the majority of the total area was found to have very high, high, and moderate levels of AV with 25, 28, and 24%, respectively. The results obtained from this study are essential for formulating plans to improve Anuradhapura’s agricultural sector resilience and adaptability to ensure food security and livelihood sustainability considering the ever-changing climate
Flow alterations due a constructed reservoir in the Menik Ganga basin, Sri Lanka
No full textAbstract
Natural water flows and their ecosystems are altered due to manmade hydraulic structures like dams. However, limited research on hydrologic alteration has been carried out in developing countries. This research explores the hydrologic alterations which occurred in the Menik Ganga basin, Sri Lanka due to the Weheragala reservoir constructed in 2009 for inter basin transfer. The hydrologic variations of the flow regime due to the construction of the reservoir was analyzed using Indicators of Hydrologic Alterations (IHA). For this purpose, we compared the calculated IHAs for streamflow at the Kataragama station (located downstream of Weheragala) during pre-construction (1990–2009) and post construction (2010–2019) periods. Also, the IHAs of simulated flows from the Water Evaluation And Planning (WEAP) model during 2010–2019 was compared with observed gauge discharge during the same period. The monthly observed flows in the “Maha” rainfall season (September to March) demonstrated a decreasing trend in post dam period with respect to pre dam period (highest decrease of 77 m3/s during October), whilst it showed an increasing trend (highest increase of 5 m3/s during August) in the Yala season (May to August) in the post-reservoir construction scenario. This was further visualized by comparing the indicators of the simulated flows with observed for post reservoir period, in which highest percentage differences occurred in June (− 4000% in 2016) and November (− 300% in 2010) for Yala and Maha periods respectively. Large alterations of the river flow due to the impoundment depicted by higher percentage differences. These alterations are extensively examined by other indicators as well. The fluctuations of flows have been decreased due to the construction of the reservoir which resulted in reductions of low and high pulses. The results are highly appealing to the authorities who are in water resources management to reach sustainable goals.Abstract
Natural water flows and their ecosystems are altered due to manmade hydraulic structures like dams. However, limited research on hydrologic alteration has been carried out in developing countries. This research explores the hydrologic alterations which occurred in the Menik Ganga basin, Sri Lanka due to the Weheragala reservoir constructed in 2009 for inter basin transfer. The hydrologic variations of the flow regime due to the construction of the reservoir was analyzed using Indicators of Hydrologic Alterations (IHA). For this purpose, we compared the calculated IHAs for streamflow at the Kataragama station (located downstream of Weheragala) during pre-construction (1990–2009) and post construction (2010–2019) periods. Also, the IHAs of simulated flows from the Water Evaluation And Planning (WEAP) model during 2010–2019 was compared with observed gauge discharge during the same period. The monthly observed flows in the “Maha” rainfall season (September to March) demonstrated a decreasing trend in post dam period with respect to pre dam period (highest decrease of 77 m3/s during October), whilst it showed an increasing trend (highest increase of 5 m3/s during August) in the Yala season (May to August) in the post-reservoir construction scenario. This was further visualized by comparing the indicators of the simulated flows with observed for post reservoir period, in which highest percentage differences occurred in June (− 4000% in 2016) and November (− 300% in 2010) for Yala and Maha periods respectively. Large alterations of the river flow due to the impoundment depicted by higher percentage differences. These alterations are extensively examined by other indicators as well. The fluctuations of flows have been decreased due to the construction of the reservoir which resulted in reductions of low and high pulses. The results are highly appealing to the authorities who are in water resources management to reach sustainable goals
Potential Inter-basin Water Transfer from the Kelani River to Mahaweli River, Sri Lanka to Mitigate Water Issues
No full textAbstract
Proper water resource management is one of the most critical problems in the world. However ongoing climate change on top of urbanization and population growth adversely impacts water resources management. Therefore, to reach the localized goals, inter-basin water transfer has been given significant attention. This paper aims to understand the importance of inter-basin water transfer from one of the water-rich basins (Kelani River Basin, Sri Lanka) to a water-stressed river basin (Mahaweli River Basin, Sri Lanka). The need for such water transfer is presented and the potential way of water transfer is understood. To be cost-effective, the proposal understands an open channel with a minimum distance of an underground tunnel to flow under gravity force. The benefits of water transfer are qualitatively evaluated under the themes of flood management, agricultural development, and hydropower development. Therefore, a sustainable water management system is expected under the inter-basin water transfer. Nevertheless, the importance of having a comprehensive hydrological and geotechnical analysis is highlighted in the paper.Abstract
Proper water resource management is one of the most critical problems in the world. However ongoing climate change on top of urbanization and population growth adversely impacts water resources management. Therefore, to reach the localized goals, inter-basin water transfer has been given significant attention. This paper aims to understand the importance of inter-basin water transfer from one of the water-rich basins (Kelani River Basin, Sri Lanka) to a water-stressed river basin (Mahaweli River Basin, Sri Lanka). The need for such water transfer is presented and the potential way of water transfer is understood. To be cost-effective, the proposal understands an open channel with a minimum distance of an underground tunnel to flow under gravity force. The benefits of water transfer are qualitatively evaluated under the themes of flood management, agricultural development, and hydropower development. Therefore, a sustainable water management system is expected under the inter-basin water transfer. Nevertheless, the importance of having a comprehensive hydrological and geotechnical analysis is highlighted in the paper
Sequential coupling of HBV-light and MODFLOW models to assess water table variations under the future climate in agricultural peatlands
No full textAbstract
Understanding water table (WT) variation is essential in peatland agriculture as the WT position is a major determinant of cultivation conditions and greenhouse gas emissions. To simulate past and future WT, we developed a sequential modelling approach by coupling two well-known models: HBV-light for cold climate hydrologic processes and MODFLOW for saturated subsurface flow conditions. We tested this approach in an agricultural peatland on Norway's west coast under two drainage configurations: a traditional pipe-drained field and an adjacent inverted peatland with a complex drainage system. In peat inversion, mineral soil excavated from below the peat is subsequently placed on top of the peat to form a protective cover layer aimed at reducing peat decomposition. Our modelling approach captured the daily WT dynamics of the fields between July 2022 and January 2025. The modelling results indicate that lateral flow dominates over the vertical flow in both drainage systems. Under future climate conditions between 2025 and 2100, the buried peat in the inverted peatland is expected to remain saturated for 25% of the time, whereas the peat in the pipe-drained field will be waterlogged rarely. Our modelling approach to simulate WT in managed peatlands can be set up relatively easily.Abstract
Understanding water table (WT) variation is essential in peatland agriculture as the WT position is a major determinant of cultivation conditions and greenhouse gas emissions. To simulate past and future WT, we developed a sequential modelling approach by coupling two well-known models: HBV-light for cold climate hydrologic processes and MODFLOW for saturated subsurface flow conditions. We tested this approach in an agricultural peatland on Norway's west coast under two drainage configurations: a traditional pipe-drained field and an adjacent inverted peatland with a complex drainage system. In peat inversion, mineral soil excavated from below the peat is subsequently placed on top of the peat to form a protective cover layer aimed at reducing peat decomposition. Our modelling approach captured the daily WT dynamics of the fields between July 2022 and January 2025. The modelling results indicate that lateral flow dominates over the vertical flow in both drainage systems. Under future climate conditions between 2025 and 2100, the buried peat in the inverted peatland is expected to remain saturated for 25% of the time, whereas the peat in the pipe-drained field will be waterlogged rarely. Our modelling approach to simulate WT in managed peatlands can be set up relatively easily
The interaction between glycemic index, glycemic load, and the genetic variant ADIPOQ T45G (rs2241766) in the risk of colorectal cancer: a case–control study in a Korean population
No full text© 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.Purpose: The glycemic index (GI), glycemic load (GL), and adiponectin level contribute to glycemic response and insulin sensitivity in the body. Studies have shown that tumor development is related to glycemic disorders; however, the results are contradictory. We aimed to investigate the association of GI and GL with colorectal cancer (CRC) risk in a Korean population and their possible interactions with the genetic variant ADIPOQ T45G. Methods and results: A case–control study including 2096 participants with 695 CRC cases was conducted. The results showed that diets with high GI or GL were significantly associated with an increased risk of CRC [odds ratio (OR) = 5.44, 95% confidence interval (CI) 3.85–7.68; OR = 4.43, 95% CI 3.18–6.15, respectively; all p-trends < 0.001]. Moreover, even with a low-GI and low-GL diet, G/G genotype carriers may have 2.93-fold and 3.77-fold higher risk of rectal cancer compared to carriers of other genotypes (T/T + T/G), (OR = 2.93, 95% CI 1.01–8.59, p-interaction = 0.011 for GI; OR = 3.77, 95% CI 1.46–9.77, p-interaction = 0.025 for GL). Conclusions: Overall, our study suggests positive associations of GI and GL with CRC risk. Moreover, the associations of GI and GL with rectal cancer risk could be modified by ADIPOQ T45G in a Korean population. Further studies with larger sample sizes are needed to confirm our findings.N
A bacteriophage infecting Mesorhizobium species has a prolate capsid and shows similarities to a family of Caulobacter crescentus phages
No full textMesorhizobium phage vB_MloS_Cp1R7A-A1 was isolated from soil planted with chickpea in Saskatchewan. It is dissimilar in sequence and morphology to previously described rhizobiophages. It is a B3 morphotype virus with a distinct prolate capsid and belongs to the tailed phage family Siphoviridae. Its genome has a GC content of 60.3% and 238 predicted genes. Putative functions were predicted for 57 genes, which include 27 tRNA genes with anticodons corresponding to 18 amino acids. This represents the highest number of tRNA genes reported yet in a rhizobiophage. The gene arrangement shows a partially modular organization. Most of the structural genes are found in one module, whereas tRNA genes are in another. Genes for replication, recombination, and nucleotide metabolism form the third module. The arrangement of the replication module resembles the replication module of Enterobacteria phage T5, raising the possibility that it uses a recombination-based replication mechanism, but there is also a suggestion that a T7-like replication mechanism could be used. Phage termini appear to be long direct repeats of just over 12 kb in length. Phylogenetic analysis revealed that Cp1R7A-A1 is more closely related to PhiCbK-like Caulobacter phages and other B3 morphotype phages than to other rhizobiophages sequenced thus far.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Embriogênese somática em pupunheira (Bactris gasipaes), butiá-da-serra (Butia eriospatha) e açai (Euterpe oleracea): isolamento e cultura de protoplastos, avaliações bioquímicas e otimização das condições de cultura
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Recursos Genéticos Vegetais, Florianópolis, 2015.A embriogênese somática (ES) é um métedo eficiente à propagaçãomassiva de plantas e à conservação de germoplasma. Em nível básico elase configura como um modelo biológico para o aprofundamento deestudos de morfogênese, fisiologia, bioquímica e genética de plantas.Muitos organismos apresentam características similares durante a ES, taiscomo a expressão de genes homólogos, o desenvolvimento de tecidosespecializados semelhantes ao observado na embriogênese zigótica e asrespostas a certos reguladores de crescimento. Para abordarprofundamente estas características associadas à ES de palmeirasneotropicais foi elaborada uma ampla revisão sobre este tema no primeirocapítulo desta dissertação. De uma forma geral esta revisão mostrou queembriões zigóticos e/ou meristemas apicais têm sido os explantes maisempregados, mostrando-se responsivos ao meio de cultura baseado naformulação salina de Murashige e Skoog suplementado com vitaminas deMorel, 3% de sacarose, carvão ativado e concentrações elevadas deauxinas, principalmente 2,4-D ou picloram. Em seguida, odesenvolvimento embrionário normalmente é estimulado em meios decultura suplementados com teores reduzidos destas auxinas e com oemprego de citocininas, notadamente BAP e 2-ip. Por fim, os embriõessão convertidos em plântulas em meios isentos de reguladores decrescimento. Além da micropropagação, muitos estudos concentraram-sena expressão de genes e na bioquímica do desenvolvimento de embriõessomáticos de palmeiras. Estudos histológicos sugeriram tendênciascomuns em diferentes espécies durante a morfogênese in vitro, tais comomorfologia semelhante dos ápices caulinares meristemáticos, calos ecélulas epidérmicas. No segundo capítulo estudou-se o emprego deculturas de protoplastos em três espécies de palmeiras, pupunha (Bactrisgasipaes), butiá-da-serra (Butia eriospatha) e açaí (Euterpe oleracea).Protoplastos são células com suas paredes celulares removidas eapresentam interesse tanto pela sua capacidade regenerativa quanto pelapossibilidade da geração de híbridos através da fusão somática de doisprotoplastos diferentes. Esta tecnologia tem sido investigada em váriasespécies de palmeiras, tais como dendê (Elaeis guineensis) e tamareira(Phoenix dactyilifera). Na presente dissertação, culturas embriogênicaspreviamente estabelecidas de pupunha, butiá-da-serra e açaí foramtratadas com uma solução enzimática composta por 2% de celulase, 0,5% de hemicelulase e 0,5 % de pectinase e em seguida elas foram23incubadas no escuro a 25 ± 2 ° C durante 6, 12, 18, ou 24 horas semagitação ou num agitador orbital a 45 rpm para o isolamento deprotoplastos. As maiores quantidades de protoplastos foram obtidasatravés da incubação em agitador orbital, sendo 5.50±0.68x105 e1.22±0.13x106 protoplastos / grama de peso fresco de pupunha e açaí,respectivamente, depois de seis horas de incubação, e 5,36 ± 2.23x105células / grama de peso fresco para butiá após 24 horas incubação.Culturas de pupunha e açaí mostraram diminuição de rendimento deprotoplastos após seis horas de incubação, enquanto a quantidade deresíduos celulares visíveis aumentou. A viabilidade de protoplastosmanteve-se elevada (> 70%), com exceção de protoplastos de açaí, cujaviabilidade diminuiu rapidamente após seis horas na incubação orbital.Os protoplastos foram cultivados usando o método de gotas de agarose oude alginato, sendo submetidos a seis tipos de meios líquidos contendo 0,1, ou 10 µM de picloram com ou sem 2µM de 2-ip. Picloram não semostrou essencial para as divisões celulares, as quais, no entanto forammais frequentes e ocorreram mais cedo em resposta a meios com níveiscrescentes do mesmo. Foram observadas microcolônias se formando nasgotas de alginato com 10 de µM picloram e 2 µM de 2-ip, no entantocolonias visíveis foram formados apenas em duas esferas de agarose. Noterceiro capítulo desta dissertação o incremento de massa seca e os teoresde proteínas, açúcares e amido foram investigados em culturas depupunha com diferentes capacidades para ES: alta capacidadeembriogênica (ACE), baixa capacidade embriogênica (BCE), e nãoembriogênica(NE). Culturas de ACE e NE apresentaram incrementos demassa seca semelhantes e que foram maiores queo incremento de massaseca em culturas de BCE. Culturas de ACE apresentaram teoresligeiramente mais elevados de proteínas do que as culturas NE, contudoambas continham maiores teores de proteínas do que as culturas de BCE.Níveis de amido foram semelhantes entre culturas de ACE e NE e queforam maiores que os níveis de amido em culturas de BCE. Níveis deaçúcares foram demasiadamente baixos para terem seus valorescalculados utilizando uma curva padrão de glicose, porém as leituras deabsorbância mostraram que as culturas de ACE e NE apresentaramvalores médios semelhantes e superiores aos níveis encontrados emculturas de BCE. Estes dados sugerem que os diferentes comportamentosde crescimento das diferentes culturas podem não refletir as quantidadestotais de proteínas, e sim os tipos de proteínas a serem expressas. A grandequantidade de amido nas culturas NE, juntamente com a morfologia24distinta destas culturas, pode sugerir uma rota regenerativa baseada naorganogênese. Além disso, é possível que a falta de reservas de energianas culturas de BCE esteja relacionada com o seu rápido crescimento.Formações de tecidos organizados também foram observadas nas culturade BCE, isto pode sugerir que a morfogênese in vitro não inclui apenasos embriões somáticos, calos, raiz e plântulas, mas pode incluir outrostipos de tecidos. No quarto capítulo buscou-se a optimização da ES emculturas de pupunha, butiá e açaí. Culturas de pupunha 'G3' foramcultivadas em meios de cultura compostos pelos sais de MS ou MSmodificado, suplementados com 1 mM de espermidina, 1 mM deespermina, ou sem poliaminas. Não houve diferença no número deembriões somáticos regenerados a partir dos meios de MS ou MSmodificado, no entanto, ambas as poliaminas apresentaram efeitosnegativos para a formação de embriões. Culturas de pupunha ?G2? foraminoculadas em meio de cultura contendo 3% de sacarose ou uma misturaigual de sacarose, glicose, frutose, e sorbitol, não revelando diferenças emtermos de números totais de embriões regenerados. Embriões zigóticos debutiá inoculados em meio MS contendo 3% sacarose, 2,5 g / L de carvãoativado e 300 µM ou 450 µM de picloram responderam com a formaçãode calos com aparência embriogênica similares aos observados empupunha, 40% e 27,5% respectivamente. No entanto, culturas friáveis debutiá foram submetidas a vários tipos de meios de cultura, incluindomeios sólidos e líquidos; diferentes concentrações de auxinas, citocininas,ABA, GA3, sacarose e carvão ativado,e ausência ou presença de luzdurante o cultivo, porém, em nenhum dos ambientes proporcionadosocorreu a formação de embriões somáticos. Além disso, desidrataçãoparcial não induziu melhorias na multiplicação das culturasde butiá, omesmo foi observado em culturas de pupunha. A multiplicação dasculturas de açaí foi melhorada com a adição 2,5 g / L de carvão ativado eaumento nos teores de picloram de 10 µM até 50 µM. O carvão ativadolevou à redução de 400% no número de explantes oxidados, um aumentono número de explantes produzindo embriões, número deembriõesformados por explante, e numero de massas poliembriogênicas porexplante. No entanto, os casos de crescimento de raizes organogênicas ede calogênese observados a partir de explantes de açaí colocadas emmeios com carvão ativado sugerem que o efeito da auxina diminui napresença de carvão ativado. Tomados em conjunto, os resultados dapresente dissertação contribuem para uma melhor compreensão dosestudos da morfogênese in vitro de palmeiras, notadamente aqueles25associados aos fatores envolvidos na tecnologia de protoplastos, àscaracterísticas bioquímicas de culturas de pupunha com diferentespotenciais embriogênicos e à otimização dos protocolos regenerativosestudados, especialmente o de açaí.Abstract : Somatic embryogenesis (SE) is a powerful technology that is useful for commercial propagation, scientific study, germplasm conservation, and has potential applications in reforestation attempts in damaged ecosystems. Many organisms show similar traits during SE, such as the expression of commonly-found gene homologs, development of specialized tissues similar to zygotic embryogenesis, and response to certain growth regulators. To summarize these trends, a review article was written (Chapter 1 of this thesis). A literature analysis of SE in the palm family, Arecaceae, suggests similar trends across palm species. Both zygotic embryos or palm shoot meristems tended to respond well to culture media composed of Murashige and Skoog salts, vitamins, 3% sucrose, exogenous activated carbon, and high concentrations of auxins, such as 2,4-D or picloram. Embryo development was usually stimulated through subculture onto media with reduced auxins and addition of cytokinin, such as BAP and 2-ip and then embryos could be frequently converted on media without growth regulators. In addition to micropropagation, many studies focused on the biochemistry and gene expression of developing palm somatic embryos. Histological studies revealed common trends, such as similar morphology of meristematic vs. callus and epidermal cells. One of the technologies that several research groups had evaluated was protoplast culture. Protoplasts, cells with their cell walls removed, are of scientific interest due to both being able to regenerate into larger cultures and the ability to create hybrids through somatic fusion of two different protoplasts. This technology has only been investigated in several large-scale economic species, such as oil palm (Elaeis guineensis) or date palm (Phoenix dactyilifera), and increased understanding of trends might lead to further development of protoplast culture as a whole (Chapter 2). To understand protoplast isolation and culture, previously-established peach palm (Bactris gasipaes), butiá-da-serra (Butia eriospatha), and açaí (Euterpe oleracea) cultures were treated with an enzyme solution composed of 2% w/v cellulase, 0.5% hemicellulase, and 0.5% pectinase and then either incubated stationary for 6, 12, 18, or 24 hours or on an orbital shaker at 45 rpm for 3, 6, 12, or 24 hours in the dark at 25±2 °C. Stationary incubation did not provide large amounts of protoplasts in comparison to incubation done on an orbital shaker. The greatest numbers of protoplasts per species were 5.50±0.68x105 and 1.22±0.13x106 protoplasts/ gram FW for peach palm and açaí after six hours of orbital shaking and 5.36±2.23x105 cells/gram FW for butiá after 24 hours of orbital shaking. Both peach palm and açaí saw dramatic decreases in protoplast yield after later incubations while the amount of visible cellular debris increased, possibly showing a potential reason for the decreased cell yield as cellular debris might lyse cells in motion. Protoplast viability remained high (>70%), except for açaí protoplasts, which decreased rapidly during orbital incubation. Protoplasts were cultured either using the agarose bead or the alginate bead method. Protoplasts cultured in alginate beads were subjected to six types of liquid media containing 0, 1, or 10µM picloram either with or without 2µM 2-ip. Auxin was not shown to be essential for causing cell division in several occasions, however cell division was more frequent and occurred earlier in media with increasing levels of picloram. 2-ip was not found to have a major impact. Microcolonies were observed to form in alginate beads with 10µM picloram and 2µM 2-ip, however visible colonies were only formed twice in agarose beads. Further optimization would be required to achieve regeneration of whole plants, however there are many trends in other species, such as use of nurse cultures, higher cell density during culture, and type of culture method, which can be pursued. The biochemistry of peach palm cultures with different capacities for SE, high embryogenic (HE), low embryogenic (LE), and non-embryogenic (NE), were investigated for dry weight, protein, sugar, and starch content (Chapter 3). It was found that both HE and NE cultures had similar dry weights, but water made up a larger proportion of LE cultures. Because of this difference, protein, sugar, and starch amounts were evaluated in terms of both fresh weight and dry weight. HE contained slightly higher amounts of protein than NE cultures, but both tissues contained higher proteins contents than LE cultures, even after adjusting for dry weight. Starch levels were comparable between HE and NE cultures, but LE cultures contained significantly fewer starch reserves. Sugar levels were too low to have their amounts calculated using a glucose standard curve, however their absorbance readings showed HE and NE cultures had the about the same values, while once again LE cultures contained fewer reserves. These data suggest that the different growth behavior of the different tissues may not reflect overall protein amounts, but rather the types of proteins being expressed. Additionally, the large amounts of starch growth, along with the distinct morphology of NE tissues might suggest a type of organogenesis. Additionally, it is possible that the lack of energy reserves found in LE tissue is related to its rapid growth. Organized tissue formations were also observed in LE tissue, possibly suggesting that in vitro organogenesis extends beyond simply somatic embryos, roots, and shoots. Additionally, SE optimization was investigated in peach palm, butiá, and açaí cultures. Peach palm tissue lines  G3 were placed on media containing either MS or modified MS salts and media containing 1mM spermidine, spermine, or no polyamines. No difference was detected in the number of somatic embryos recovered from MS or modified MS cultures, however either polyamine had a negative effect. Peach palm  G2 cultures were placed on media containing either 3% sucrose or an equal mix of sucrose, glucose, or sorbitol with no difference in total numbers of recovered embryos. Fast-growing friable butiá cultures were subjected to numerous types of media, including both solid and liquid media, media containing different concentrations of auxins, cytokinins, ABA, GA3, sucrose, and activated charcoal in both light and dark, but no somatic embryos were induced. Additionally, partial dehydration did not induce improved peach palm multiplication nor butiá SE. However, 40% and 27.5% placed on MS media containing 2.5g/L activated charcoal and 300µM or 450µM, respectively, picloram responded with tissue growth similar to that found in peach palm highly embryogenic tissue. Açaí multiplication was greatly improved through optimizing multiplication media with addition 2.5g/L activated charcoal and increased picloram up to 50µM from 10µM. The effects of the activated charcoal led to 400% reduction in number of oxidized explants, an increase in number of explants producing embryos, embryos per explant, number of embryos producing polyembryogenic masses, and number of polyembryogenic masses per explant. However, instances of organogenic root growth and increased callogenesis were observed on açaí explants placed on media with activated charcoal, which suggests that the decreased effect of auxin caused by activated charcoal can reduce embryogenic potential. Together, these works contribute to better understanding the trends found in multiple palms, factors involved in the valuable technology of protoplast culture, the biochemical characteristics of several types of peach palm tissue with different embryogenic potential, and cultural optimization, especially for the economically valuable açaí palm
Filaggrin deficiency confers a paracellular barrier abnormality that reduces inflammatory thresholds to irritants and haptens
No full textBackground: Mutations in the human filaggrin gene (FLG) are associated with atopic dermatitis (AD) and are presumed to provoke a barrier abnormality. Yet additional acquired stressors might be necessary because the same mutations can result in a noninflammatory disorder, ichthyosis vulgaris. Objective: We examined here whether FLG deficiency alone suffices to produce a barrier abnormality, the basis for the putative abnormality, and its proinflammatory consequences. Methods: By using the flaky-tail mouse, which lacks processed murine filaggrin because of a frameshift mutation in the gene encoding profilaggrin that mimics some mutations in human AD, we assessed whether FLG deficiency provokes a barrier abnormality, further localized the defect, identified its subcellular basis, and assessed thresholds to irritant- and hapten-induced dermatitis. Results: Flaky-tail mice exhibit low-grade inflammation with increased bidirectional, paracellular permeability of water-soluble xenobiotes caused by impaired lamellar body secretion and altered stratum corneum extracellular membranes. This barrier abnormality correlates with reduced inflammatory thresholds to both topical irritants and haptens. Moreover, when exposed repeatedly to topical haptens at doses that produce no inflammation in wild-type mice, flaky-tail mice experience a severe AD-like dermatosis with a further deterioration in barrier function and features of a T(H)2 immunophenotype (increased CRTH levels plus inflammation, increased serum IgE levels, and reduced antimicrobial peptide [mBD3] expression). Conclusions: FLG deficiency alone provokes a paracellular barrier abnormality in mice that reduces inflammatory thresholds to topical irritants/haptens, likely accounting for enhanced antigen penetration in FLG-associated AD. (J Allergy Clin Immunol 2009;124:496-506.)AllergyImmunologySCI(E)50ARTICLE3496-U16412
