Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact betwe...Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact between microbial cells and growth substrates, having a pivotal role in organic film formation and bacterium-substratum interactions. The production and chemical composition of EPS produced by seven bioleaching strains grown with different substrates were studied. Analysis of the EPS extracted from these strains indicated that the EPS consisted of carbohydrates, proteins and galacturonic acid. The contents of EPS, carbohydrates, proteins and galacturonic acid of EPS were largely related to the kind of strain used and culture condition. The results show that EPS productions of microbes grown with pyrite were significantly higher than those of microbes grown with sulfur or FeSO4·7H2O. The highest EPS production of the seven acidiphilic strains was （159.43±3.93） mg/g, which was produced by Leptospirillum ferriphilum CBCBSUCSU208015 when cultivated with pyrite.展开更多
The apple rootstock, A106 (Malus sieboldii), had 17 bivalents in pollen mother cells at meiotic metaphase 1,and 17 chromosomes in a haploid pollen cell. Karyotypes were prepared from root-tip cells with 2n= 34 chromos...The apple rootstock, A106 (Malus sieboldii), had 17 bivalents in pollen mother cells at meiotic metaphase 1,and 17 chromosomes in a haploid pollen cell. Karyotypes were prepared from root-tip cells with 2n= 34 chromosomes. Seven out of 82 karyotypes (8.5%) showed one pair of satellites at the end of the short arm of chromosome 3. C-bands were shown on 6 pairs of chromosomes 2, 4,6, 8, 14, and 16 near the telomeric regions of short arms.Probes for three ripening-related genes from Malus x domestica: endopolygalacturonase (EPG,0. 6 kb ) , ACC oxidase (1.2 kb), and ACC synthase (2 kb) were hybridized in situ to metaphase chromosomes of A106. Hybridization sites for the EPG gene were observed on the long arm of chromosome 14 in 15 out of 16 replicate spreads and proximal to the centromere of chromosomes 6 and 11. For the ACC oxidase gene, hybridization sites were observed in the telomeric region of the short arm of chromosomes 5 and 11 in 87% and 81% of 16 spreads respectively proximal to the centromere of chromosome 1 in 81% of the spreads, and on the long arm of chromosome 13 in 50% of the spreads. Twenty five spreads were studied for the ACC synthase gene and hybridization sites were observed in the telomeric region of the short arm of chromosome 12 in 96% of the spreads, chromosomes 9 and 10 in 76% of the spreads, and chromosome 17 in 56% of the spreads.展开更多
Tuber slices of newly introduced potato cultivars （cvs） in Libya, namely Spunta, Pamela, Daisy, Daifla, Atlas and Apollina were tested for their susceptibility to soft rot bacterium （Erwinia carotovora subsp, carot...Tuber slices of newly introduced potato cultivars （cvs） in Libya, namely Spunta, Pamela, Daisy, Daifla, Atlas and Apollina were tested for their susceptibility to soft rot bacterium （Erwinia carotovora subsp, carotovora）. Atlas cv was proved to be the most susceptible cv, meanwhile, Daisy cv was the most resistant one. The activities of pectolytic and oxidative enzymes in diseased tubers were profoundly higher than these in healthy ones. The highest enzymatic activities of pectin methyl esterase （PME） and polygalacturonase （PG） were observed in diseased tubers of Daifla cv. However, diseased tubers of Spunta gave the highest activities of polymethyl galacturonase （PMG）. On the other hand, the highest significant activities of the enzyme PME in healthy tubers was detected in Pamela cv compared to other cvs. Moreover, there were insignificant differences in PG and PMG enzymes activities between healthy tubers of the different cvs. The cv Daisy gave the highest activity of the enzyme peroxidase （PO） in diseased tubers, whereas the highest activity of enzyme polyphenol oxidase （PPO） was detected in infected tubers of Atlas cv. Concerning healthy tubers, the highest activities of enzymes PO and PPO were noticed in Atlas and Pamella cvs respectively as compared to other cvs. Electrolyte leakage from plant cells was estimated by measuring electrical conductivity as indicator for permeability changes in potato tissues. Values of electrolyte leakage in infected tubers of all tested cvs showed significant increase compared with those of healthy ones, especially, with the most susceptible one.展开更多
AIM：To investigate the association of variations in the cyclooxygenase-2 （COX2） and uridine diphosphate glucuronosyltransferase 1A6 （UGTIA6） genes and non-steroidal anti-inflammatory drugs （NSAIDs） use with ris...AIM：To investigate the association of variations in the cyclooxygenase-2 （COX2） and uridine diphosphate glucuronosyltransferase 1A6 （UGTIA6） genes and non-steroidal anti-inflammatory drugs （NSAIDs） use with risk of colon cancer.METHODS： NSAIDs, which are known to reduce the risk of colon cancer, act directly on COX2 and reduce its activity. Epidemiological studies have associated variations in the COX2 gene with colon cancer risk, but others were unable to replicate this finding. Similarly,enzymes in the UGT1A6 gene have been demonstrated to modify the therapeutic effect of NSAIDs on colon adenomas. Polymorphisms in the UGTIA6 gene have been statistically shown to interact with NSAID intake to influence risk of developing colon adenomas, but not colon cancer. Here we examined the association of tagging single nucleotide polymorphisms （SNPs） in the COX2 and UGTIA6 genes, and their interaction with NSAID consumption, on risk of colon cancer in a population of 422 colon cancer cases and 481 population controls.RESULTS： No SNP in either gene was individually statistically significantly associated with colon cancer, nor did they statistically significantly change the protective effect of NSAID consumption in our sample. Like others, we were unable to replicate the association of variants in the COX2 gene with colon cancer risk （P 〉 0.05）,and we did not observe that these variants modify the protective effect of NSAIDs （P 〉 0.05）. We were able to confirm the lack of association of variants in UGT1A6 with colon cancer risk, although further studies will have to be conducted to confirm the association of these variants with colon adenomas.CONCLUSION： Our study does not support a role of COX2 and UGTIA6 genetic variations in the development of colon cancer.展开更多
Uridine diphosphate-glucose dehydrogenase （UGD, EC1.1.1 glucuronate）, a critical precursor of cell wall polysaccharides 22 oxidizes UDP-Glc （UDP-D-glucose） to UDP-GlcA （UDP-D- GbUGD6 from Gossypium barbadense is ...Uridine diphosphate-glucose dehydrogenase （UGD, EC1.1.1 glucuronate）, a critical precursor of cell wall polysaccharides 22 oxidizes UDP-Glc （UDP-D-glucose） to UDP-GlcA （UDP-D- GbUGD6 from Gossypium barbadense is more highly expressed late in the elongation of cotton fibers （15 d post-anthesis （DPA）） and during the stage of secondary cell wall thickening （30 DPA）. Subcellular localization analysis in onion epidermis revealed that fluorescently labeled GbUGD6 protein was distribut- ed throughout the cell membrane, as well as the nucleus and vacuoles. Examination of UGD function in Arabidopsis revealed that the antisense GbUGD6 lines had shorter roots, deferred blossoming, compared to wild-type plants. Activities of associated enzymes were also affected by UGD reduction, and biochemical analysis of cell wall samples showed an increase in cellulose levels and a decrease in UGP-GlcA contents. The results of the present study as well as previous studies on UGD support the conclusion that UGD plays a major role in synthesizing polysaccharides synthesis in the cell wall.展开更多
文摘Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact between microbial cells and growth substrates, having a pivotal role in organic film formation and bacterium-substratum interactions. The production and chemical composition of EPS produced by seven bioleaching strains grown with different substrates were studied. Analysis of the EPS extracted from these strains indicated that the EPS consisted of carbohydrates, proteins and galacturonic acid. The contents of EPS, carbohydrates, proteins and galacturonic acid of EPS were largely related to the kind of strain used and culture condition. The results show that EPS productions of microbes grown with pyrite were significantly higher than those of microbes grown with sulfur or FeSO4·7H2O. The highest EPS production of the seven acidiphilic strains was （159.43±3.93） mg/g, which was produced by Leptospirillum ferriphilum CBCBSUCSU208015 when cultivated with pyrite.
文摘The apple rootstock, A106 (Malus sieboldii), had 17 bivalents in pollen mother cells at meiotic metaphase 1,and 17 chromosomes in a haploid pollen cell. Karyotypes were prepared from root-tip cells with 2n= 34 chromosomes. Seven out of 82 karyotypes (8.5%) showed one pair of satellites at the end of the short arm of chromosome 3. C-bands were shown on 6 pairs of chromosomes 2, 4,6, 8, 14, and 16 near the telomeric regions of short arms.Probes for three ripening-related genes from Malus x domestica: endopolygalacturonase (EPG,0. 6 kb ) , ACC oxidase (1.2 kb), and ACC synthase (2 kb) were hybridized in situ to metaphase chromosomes of A106. Hybridization sites for the EPG gene were observed on the long arm of chromosome 14 in 15 out of 16 replicate spreads and proximal to the centromere of chromosomes 6 and 11. For the ACC oxidase gene, hybridization sites were observed in the telomeric region of the short arm of chromosomes 5 and 11 in 87% and 81% of 16 spreads respectively proximal to the centromere of chromosome 1 in 81% of the spreads, and on the long arm of chromosome 13 in 50% of the spreads. Twenty five spreads were studied for the ACC synthase gene and hybridization sites were observed in the telomeric region of the short arm of chromosome 12 in 96% of the spreads, chromosomes 9 and 10 in 76% of the spreads, and chromosome 17 in 56% of the spreads.
文摘Tuber slices of newly introduced potato cultivars （cvs） in Libya, namely Spunta, Pamela, Daisy, Daifla, Atlas and Apollina were tested for their susceptibility to soft rot bacterium （Erwinia carotovora subsp, carotovora）. Atlas cv was proved to be the most susceptible cv, meanwhile, Daisy cv was the most resistant one. The activities of pectolytic and oxidative enzymes in diseased tubers were profoundly higher than these in healthy ones. The highest enzymatic activities of pectin methyl esterase （PME） and polygalacturonase （PG） were observed in diseased tubers of Daifla cv. However, diseased tubers of Spunta gave the highest activities of polymethyl galacturonase （PMG）. On the other hand, the highest significant activities of the enzyme PME in healthy tubers was detected in Pamela cv compared to other cvs. Moreover, there were insignificant differences in PG and PMG enzymes activities between healthy tubers of the different cvs. The cv Daisy gave the highest activity of the enzyme peroxidase （PO） in diseased tubers, whereas the highest activity of enzyme polyphenol oxidase （PPO） was detected in infected tubers of Atlas cv. Concerning healthy tubers, the highest activities of enzymes PO and PPO were noticed in Atlas and Pamella cvs respectively as compared to other cvs. Electrolyte leakage from plant cells was estimated by measuring electrical conductivity as indicator for permeability changes in potato tissues. Values of electrolyte leakage in infected tubers of all tested cvs showed significant increase compared with those of healthy ones, especially, with the most susceptible one.
基金Supported by A Damon Runyon Cancer Research Foundation Clinical Investigator Award,CI-8An R25 training grant from the National Cancer Institute,R25T CA094186+1 种基金The Case Center for Transdisciplinary Research on Energetics and Cancer,1U54 CA-116867-01A National Cancer Institute K22 Award,1K22 CA120545-01
文摘AIM：To investigate the association of variations in the cyclooxygenase-2 （COX2） and uridine diphosphate glucuronosyltransferase 1A6 （UGTIA6） genes and non-steroidal anti-inflammatory drugs （NSAIDs） use with risk of colon cancer.METHODS： NSAIDs, which are known to reduce the risk of colon cancer, act directly on COX2 and reduce its activity. Epidemiological studies have associated variations in the COX2 gene with colon cancer risk, but others were unable to replicate this finding. Similarly,enzymes in the UGT1A6 gene have been demonstrated to modify the therapeutic effect of NSAIDs on colon adenomas. Polymorphisms in the UGTIA6 gene have been statistically shown to interact with NSAID intake to influence risk of developing colon adenomas, but not colon cancer. Here we examined the association of tagging single nucleotide polymorphisms （SNPs） in the COX2 and UGTIA6 genes, and their interaction with NSAID consumption, on risk of colon cancer in a population of 422 colon cancer cases and 481 population controls.RESULTS： No SNP in either gene was individually statistically significantly associated with colon cancer, nor did they statistically significantly change the protective effect of NSAID consumption in our sample. Like others, we were unable to replicate the association of variants in the COX2 gene with colon cancer risk （P 〉 0.05）,and we did not observe that these variants modify the protective effect of NSAIDs （P 〉 0.05）. We were able to confirm the lack of association of variants in UGT1A6 with colon cancer risk, although further studies will have to be conducted to confirm the association of these variants with colon adenomas.CONCLUSION： Our study does not support a role of COX2 and UGTIA6 genetic variations in the development of colon cancer.
基金the Ministry of Agriculture of China (2014ZX08009-003)the Hebei Province Technology Support Program (14962905D)the Hebei Province Department of Education Fund (Y2012025)
文摘Uridine diphosphate-glucose dehydrogenase （UGD, EC1.1.1 glucuronate）, a critical precursor of cell wall polysaccharides 22 oxidizes UDP-Glc （UDP-D-glucose） to UDP-GlcA （UDP-D- GbUGD6 from Gossypium barbadense is more highly expressed late in the elongation of cotton fibers （15 d post-anthesis （DPA）） and during the stage of secondary cell wall thickening （30 DPA）. Subcellular localization analysis in onion epidermis revealed that fluorescently labeled GbUGD6 protein was distribut- ed throughout the cell membrane, as well as the nucleus and vacuoles. Examination of UGD function in Arabidopsis revealed that the antisense GbUGD6 lines had shorter roots, deferred blossoming, compared to wild-type plants. Activities of associated enzymes were also affected by UGD reduction, and biochemical analysis of cell wall samples showed an increase in cellulose levels and a decrease in UGP-GlcA contents. The results of the present study as well as previous studies on UGD support the conclusion that UGD plays a major role in synthesizing polysaccharides synthesis in the cell wall.
