The hypothesis that a dietary Supplement of selenium (Se) may reduce cancer risk was tested experimetally in humans. Patients with histories of basal/squarnous cell carcinomas of the skin were assigned randomly in dou...The hypothesis that a dietary Supplement of selenium (Se) may reduce cancer risk was tested experimetally in humans. Patients with histories of basal/squarnous cell carcinomas of the skin were assigned randomly in double-blind fashion to dally oral supplements of either Seenriched yeast (200 μg Se/day), or a low-Se yeast placebo. A total of 1312 patients recruited in 1983-1990 were followed with regular dermatologic examinations through 1993 for a total of 8269 person-years of observation. Skin cancer diagnoses were confirmed histologically.Plasma Se concentration was determined at 6-12 months intervals. All deaths and patient-reported illnesses were recorded; reported cancers were confirmed and documented by consultation with the patient medical care providers. The results indicate that Se did not significantly affect the primary endpoints: incidences of recurrent basal/squarnous cell carcinomas of the skin. However, Setreatment was associated with reductions in several secondary endpoints:total mortality, mortality from all cancers combined, as well as the incidence of all cancers combined, lung cancer, colorectal cancer and prostate cancer. The consistencies of these associations over time, between study clinics and for the leading cancer sltes strongly suggests benefits of Se-supplementation for this cohort of patients, supporting the hypopthesis that supplemental Se can reduce cancer risk. Although Se did no shown protective effects against nonmelanoma skin cancers, the suggested reductions in risks to other frequent cancers demand further evaluation in well controlled cliflical intervention trials展开更多
Objective To establish an effective assay to access the effects of natural products on cathepsin K for screening antiosteoporosis drugs. Methods To obtain the purified cathepsin K, we cloned the target fragment fro...Objective To establish an effective assay to access the effects of natural products on cathepsin K for screening antiosteoporosis drugs. Methods To obtain the purified cathepsin K, we cloned the target fragment from the mRNA of human osteosacoma cell line MG63 and demonstrated its correctness through DNA sequencing. Cathepsin K was expressed in a high amount in E.coli after IPTG induction, and was purified to near homogenetity through resolution and column purification. The specificity of the protein was shown by Western blotting experiment. The biological activity of the components in the fermentation broth was assayed by their inhibitory effects on cathepsin K and its analog papain. Results With the inhibition of papain activity as a screen index, the fermentation samples of one thousand strains of fungi were tested and 9 strains among them showed strong inhibitory effects. The crude products of the fermentation broth were tested for their specific inhibitory effects on the purified human cathepsin K, the product of fungi 2358 shows the highest specificity against cathepsin K. Conclusions The compounds isolated from fungi 2358 show the highest biological activity and are worth further structure elucidation and function characterization.展开更多
AIM: To explore the inhibition of conjugated linoleic acidisomers in different purity (75 % purity c9,t11-, 98 % purityc9,t11- and 98 % purity t10,c12-CLA) on the formation offorestomach neoplasm and cheopreventive me...AIM: To explore the inhibition of conjugated linoleic acidisomers in different purity (75 % purity c9,t11-, 98 % purityc9,t11- and 98 % purity t10,c12-CLA) on the formation offorestomach neoplasm and cheopreventive mechanisms.METHODS: Forestomach neoplasm model induced by B(a)P in KunMing mice was established. The numbers of tumorand diameter of each tumor in forestomach were counted;the mice plasma malondialdehyde (MDA) were measuredby TBARS assay; TUNEL assay was used to analyze theapoptosis in forestomach neoplasia and the expression ofMEK-1, ERK-1, MKP-1 protein in forestomach neoplasm werestudied by Western Blotting assay.RESULTS: The incidence of neoplasm in B(a)P group, 75 %purity c9, t11-CLA group, 98 % purity cg,t11-CLA groupand 98 % purity t10, c12-CLA group was 100 %, 75.0 %(P＞0.05), 69.2 % (P＜0.05) and 53.8 % (P＜0.05) respectivelyand the effect of two CLA isomers in 98 % purity onforestomach neoplasia was significant; CLA showed noinfluence on the average tumor numbers in tumor-bearingmouse, but significantly decreased the tumor size, the tumoraverage diameter of mice in 75 % purity c9,t11-CLA group,98 % purity cg,t11-CLA group and 98 % purity t10, c12-CLAgroup was 0.157±0.047 cm, 0.127±0.038 cm and 0.128±0.077 cm (P＜0.05) and 0.216±0.088 cm in B(a)P group;CLA could also significantly increase the apoptosis cellnumbers by 144.00±20.31, 153.75±23.25, 157.25±15.95(P＜0.05) in 75 % purity c9,t11-CLA group, 98 % purity c9,t11-CLA group and 98 % purity t10,c12-CLA group (30.88±3.72 in BP group); but there were no significant differencesbetween the effects of 75 % purity c9,t11-CLA and twoisomers in 98 % purity on tumor size and apoptotic cellnumbers; the plasma levels of MDA in were increased by75 % purity c9,t11-ClA, 98 % purity c9,t11-CLA and 98 %purity t10,c12-CLA. The 75 % purity c9,t11-CLA showedstronger inhibition; CLA could also inhibit the expression ofERK-1 protein and promote the expression of MKP-1 protein,however no influence of CLA on MEK-1 protein was observed.CONCLUSION: Two isomers in 98 % purity show strongerinhibition on carcinogenesis. However, the inhibitorymechanisms of CLA on carcinogenesis is complicated, whichmay be due to the increased mice plasmaMDA, the inducingapoptosis in tumor tissues. And the effect of CLA on theexpression of ERK-1 and MKP-1 may be one of themechanisms of the inhibition of CLA on the tumor.展开更多
Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possi...Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance to Magnaporthe grisea was found in all kinds of regenerated plants including that with single gluc78. A few lines expressing either ech42 or nag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs from Trichoderma atroviride that result in resistance to blast and sheath blight in rice.展开更多
An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae sp...An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae species, Ulva pertusa (Chlorophyta), Gelidium amansii (Rhodophyta) and Sargassum enerve (Phaeophyta), were chosen for the experiment because of their economic values and availability. Control and four nitrogen concentrations were achieved by adding NH + 4 and NO - 3. The results indicate that the fresh weights of all species increase faster than that of control after 5 d culture. The fresh weight of Ulva pertusa increases fastest among the 3 species. However, different species show different responses to nitrogen source and its availability. They also show the advantage of using NH + 4 than using NO - 3. U. pertusa grows best and shows higher capability of removing nitrogen at 200 μmol L -1 , but it has lower economical value. G. amansii has higher economical value but lower capability of removing nitrogen at 200 μmol L -1 . The capability of nitrogen assimilation of S. enerve is higher than that of G. amansii at 200 μmol L -1 , but the former’s increase of fresh weight is lower than those of other two species. Then present preliminary study demonstrates that it is possible to use macroalgae as biofilters and further development of this approach could provide biologically valuable information on the source, fate, and transport of N in marine ecosystems. Caution is needed should we extrapolate these findings to natural environments.展开更多
AIM: To investigate the effect of c9, t11-conjugated linoleic acid (c9,t11-CLA) on the adhesion of human gastric carcinoma cell line (SGC-7901).METHODS: SGC-7901 cells were at first treated with different concentratio...AIM: To investigate the effect of c9, t11-conjugated linoleic acid (c9,t11-CLA) on the adhesion of human gastric carcinoma cell line (SGC-7901).METHODS: SGC-7901 cells were at first treated with different concentrations (25, 50, 100, 200 μmol/L) of c9,t111-CLA and 1 mL/L ethanol (as a negative control) for 24 h.Using adhesion assay and Western blot, we investigated the ability of SGC-7901 cells to adhere to intracellular matrix and examined the expression of E-cadherin (ECD), α-catenin,intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in these cells.RESULTS: The attachment rate to laminin of SGC-7901 cells treated with different concentrations of c9,t11-CLA (0,25, 50, 100, and 200 μmol/L) was 100.0±3.3, 95.7±4.0,89.2±4.6, 87.9±6.1, and 65.9±5.8, respectively. The attachment rate to fibronectin was 100.0±4.7, 96.8±3.8,94.5±4.1, 76.5±4.3, and 61.8±4.8, respectively. The attachment rate to Matrigel was 99.9±6.6, 91.4±6.8,85.5±7.4, 79.3±5.6, and 69.6±5.1, respectively. Besides,c9,t11-CLA could increase the level of ECD and α-catenin,and decrease the level of ICAM-1 and VCAM-1 in SGC-7901 cells.CONCLUSION: c9, t11-CLA can reduce the adhesion of human gastric carcinoma cells to laminin, fibronectin and Matrigel. c9,t11-CLA can increase the level of ECD and α-catenin, and decrease the level of ICAM-1 and VCAM-1 in human gastric carcinoma cells.展开更多
Trichoderma harzianum strain T22 controls various diseases of maize and other crops, including seedling and root rots caused by Pythium ultimum. Seedlings of inbred line Mo17 were grown from T22-treated or untreated s...Trichoderma harzianum strain T22 controls various diseases of maize and other crops, including seedling and root rots caused by Pythium ultimum. Seedlings of inbred line Mo17 were grown from T22-treated or untreated seeds in field soil or in field soil intested with the pathogen. Five days after planting, seedlings of Mo17 (5-days-old) were smaller in the presence of P. ultimum and larger in the presence of T22 relative to the control. The combination of T22 with P. ultimum (T22+ P. ultimum ) resulted in plants as large as T22 alone. Methods for protein extraction and 2-D gel electrophoresis were developed. Proteins in seedlings roots from the various treatments were separated on 2-D gels and analyzed using PDQuest TM. 2-D software. With seedlings produced from T22-treated seeds, there were 104 unmatched proteins and 164 matched proteins relative to the control, and 97 and 150 from the treatment with T22+ P. ultimum, respectively, however, with P. ultimum alone the numbers were much lower than above two treatments. Comparatively, there was very lower similarity of proteome patterns of seedling roots with T22 or P. ultimum or both to control seedlings, the correlative coefficient values were 0.72, 0.51 and 0.49 for the comparisons among control with T22, P. ultimum and T22+ P. ultimum, respectively. Moreover, correlative coefficient of proteome patterns between T22 with P. ultimum was only 0.65, and T22 fungal proteome were also not same as any one of seedling roots with various treatments. Taken together, the components in seedling root proteome seemed to be mostly coming from Mo17 plants themselves and affected strongly by either microbes, but the effects appeared to be stronger by P. ultimum than by T22. 41 spots were selected for protein mass fingerprinting identification, and most detected-spots were intensified in abundance by T22 or T22+ P.ultimum treatments such as pathogenesis-related protein and endochitnase etc. SOD (Mn) was found to be involved in the defensive reaction of host against P. ultimum because the protein only appeared in the treatment with T22 or T22+ P.ultimum. Besides, some proteins associated with host respiration, nutrition synthesis and transport appeared to be in coordination with defensive-related proteins against the damping off.展开更多
Three genes encoding for fungal cell wall degrading enzymes (CWDE), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possib...Three genes encoding for fungal cell wall degrading enzymes (CWDE), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations. The coding sequences were placed downstream of the rice actin promoter and all vectors were used to transform rice plants. A total of more than 1,800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. Expression in plant was obtained for all the fungal genes used singly or in combinations. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had a lesser effect. The expression level of endochitinase but not of the exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the positive effect of endochitinase on disease resistance when two genes were co-expressed in transgenic rice. Improved resistance to Magnaporthe grisea was found in all types of regenerated plants, including those with the gluc78 gene alone, while a few lines expressing either ech42 or nag70 appeared to be immune to this pathogen. Transgenic plants expressing the gluc78 gene alone were stunted and only few of them survived, even though they showed resistance to M. grisea. However, combination with either one of the two other genes (ech42, nag70) as included in the same T-DNA region, reduced the negative effect of gluc78 on plant growth. This is the first report of single or multiple of expression of transgens encoding CWDEs that results in resistance to blast and sheath blight in rice.展开更多
The structure type for the crystal of 4,4'-bis-(2-hydroxy-ethoxyl)-biphenyl 1 has been predicted by using the previously developed interfacial model for small organic molecules. Based on the calculated hydrophobic...The structure type for the crystal of 4,4'-bis-(2-hydroxy-ethoxyl)-biphenyl 1 has been predicted by using the previously developed interfacial model for small organic molecules. Based on the calculated hydrophobic to hydrophilic volume of 1, this model predicts the crystal structure to be of lamellar or bicontinuous type, which has been confirmed by the X-ray single-crystal structure analysis (C20H26O6, monoclinic, P21/C, a = 16.084(1), b = 6.0103(4), c = 9.6410(7) A, β9 = 103.014(2)°, V= 908.1(1) A3, Z = 2, Dc= 1.325 g/cm3, F(000)=388,μ = 0.097 mm-1, MoKα radiation, λ = 0.71073 A, R = 0.0382 and wR = 0.0882 with I > 2σ(I) for 7121 reflections collected, 1852 unique reflections and 170 parameters). As predicted, the hydrophobic and hydrophilic portions of 1 form in the lamellae. The same interfacial model is applied to other amphilphilic small molecule organic systems for structural type prediction.展开更多
基金partially funded by the National Science Foundation of China
the Major State Basic Research Program of the PeoplesRepublic of China( No.G19990 43 2 0 2)
文摘The hypothesis that a dietary Supplement of selenium (Se) may reduce cancer risk was tested experimetally in humans. Patients with histories of basal/squarnous cell carcinomas of the skin were assigned randomly in double-blind fashion to dally oral supplements of either Seenriched yeast (200 μg Se/day), or a low-Se yeast placebo. A total of 1312 patients recruited in 1983-1990 were followed with regular dermatologic examinations through 1993 for a total of 8269 person-years of observation. Skin cancer diagnoses were confirmed histologically.Plasma Se concentration was determined at 6-12 months intervals. All deaths and patient-reported illnesses were recorded; reported cancers were confirmed and documented by consultation with the patient medical care providers. The results indicate that Se did not significantly affect the primary endpoints: incidences of recurrent basal/squarnous cell carcinomas of the skin. However, Setreatment was associated with reductions in several secondary endpoints:total mortality, mortality from all cancers combined, as well as the incidence of all cancers combined, lung cancer, colorectal cancer and prostate cancer. The consistencies of these associations over time, between study clinics and for the leading cancer sltes strongly suggests benefits of Se-supplementation for this cohort of patients, supporting the hypopthesis that supplemental Se can reduce cancer risk. Although Se did no shown protective effects against nonmelanoma skin cancers, the suggested reductions in risks to other frequent cancers demand further evaluation in well controlled cliflical intervention trials
文摘Objective To establish an effective assay to access the effects of natural products on cathepsin K for screening antiosteoporosis drugs. Methods To obtain the purified cathepsin K, we cloned the target fragment from the mRNA of human osteosacoma cell line MG63 and demonstrated its correctness through DNA sequencing. Cathepsin K was expressed in a high amount in E.coli after IPTG induction, and was purified to near homogenetity through resolution and column purification. The specificity of the protein was shown by Western blotting experiment. The biological activity of the components in the fermentation broth was assayed by their inhibitory effects on cathepsin K and its analog papain. Results With the inhibition of papain activity as a screen index, the fermentation samples of one thousand strains of fungi were tested and 9 strains among them showed strong inhibitory effects. The crude products of the fermentation broth were tested for their specific inhibitory effects on the purified human cathepsin K, the product of fungi 2358 shows the highest specificity against cathepsin K. Conclusions The compounds isolated from fungi 2358 show the highest biological activity and are worth further structure elucidation and function characterization.
基金the National Natural Science Foundation ot China, No.30070658
文摘AIM: To explore the inhibition of conjugated linoleic acidisomers in different purity (75 % purity c9,t11-, 98 % purityc9,t11- and 98 % purity t10,c12-CLA) on the formation offorestomach neoplasm and cheopreventive mechanisms.METHODS: Forestomach neoplasm model induced by B(a)P in KunMing mice was established. The numbers of tumorand diameter of each tumor in forestomach were counted;the mice plasma malondialdehyde (MDA) were measuredby TBARS assay; TUNEL assay was used to analyze theapoptosis in forestomach neoplasia and the expression ofMEK-1, ERK-1, MKP-1 protein in forestomach neoplasm werestudied by Western Blotting assay.RESULTS: The incidence of neoplasm in B(a)P group, 75 %purity c9, t11-CLA group, 98 % purity cg,t11-CLA groupand 98 % purity t10, c12-CLA group was 100 %, 75.0 %(P＞0.05), 69.2 % (P＜0.05) and 53.8 % (P＜0.05) respectivelyand the effect of two CLA isomers in 98 % purity onforestomach neoplasia was significant; CLA showed noinfluence on the average tumor numbers in tumor-bearingmouse, but significantly decreased the tumor size, the tumoraverage diameter of mice in 75 % purity c9,t11-CLA group,98 % purity cg,t11-CLA group and 98 % purity t10, c12-CLAgroup was 0.157±0.047 cm, 0.127±0.038 cm and 0.128±0.077 cm (P＜0.05) and 0.216±0.088 cm in B(a)P group;CLA could also significantly increase the apoptosis cellnumbers by 144.00±20.31, 153.75±23.25, 157.25±15.95(P＜0.05) in 75 % purity c9,t11-CLA group, 98 % purity c9,t11-CLA group and 98 % purity t10,c12-CLA group (30.88±3.72 in BP group); but there were no significant differencesbetween the effects of 75 % purity c9,t11-CLA and twoisomers in 98 % purity on tumor size and apoptotic cellnumbers; the plasma levels of MDA in were increased by75 % purity c9,t11-ClA, 98 % purity c9,t11-CLA and 98 %purity t10,c12-CLA. The 75 % purity c9,t11-CLA showedstronger inhibition; CLA could also inhibit the expression ofERK-1 protein and promote the expression of MKP-1 protein,however no influence of CLA on MEK-1 protein was observed.CONCLUSION: Two isomers in 98 % purity show strongerinhibition on carcinogenesis. However, the inhibitorymechanisms of CLA on carcinogenesis is complicated, whichmay be due to the increased mice plasmaMDA, the inducingapoptosis in tumor tissues. And the effect of CLA on theexpression of ERK-1 and MKP-1 may be one of themechanisms of the inhibition of CLA on the tumor.
基金Project (No.3997002) supported by the National Natural Science Foundation of China
文摘Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance to Magnaporthe grisea was found in all kinds of regenerated plants including that with single gluc78. A few lines expressing either ech42 or nag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs from Trichoderma atroviride that result in resistance to blast and sheath blight in rice.
基金supported by the Natural Science Foundation of China(Nos. 40206020,40306025)National Fundamental Research Program of China(No.2001CB409702)the US National Science Foundation
文摘An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae species, Ulva pertusa (Chlorophyta), Gelidium amansii (Rhodophyta) and Sargassum enerve (Phaeophyta), were chosen for the experiment because of their economic values and availability. Control and four nitrogen concentrations were achieved by adding NH + 4 and NO - 3. The results indicate that the fresh weights of all species increase faster than that of control after 5 d culture. The fresh weight of Ulva pertusa increases fastest among the 3 species. However, different species show different responses to nitrogen source and its availability. They also show the advantage of using NH + 4 than using NO - 3. U. pertusa grows best and shows higher capability of removing nitrogen at 200 μmol L -1 , but it has lower economical value. G. amansii has higher economical value but lower capability of removing nitrogen at 200 μmol L -1 . The capability of nitrogen assimilation of S. enerve is higher than that of G. amansii at 200 μmol L -1 , but the former’s increase of fresh weight is lower than those of other two species. Then present preliminary study demonstrates that it is possible to use macroalgae as biofilters and further development of this approach could provide biologically valuable information on the source, fate, and transport of N in marine ecosystems. Caution is needed should we extrapolate these findings to natural environments.
基金Supported by the National Natural Science Foundation of China,No.30070658
文摘AIM: To investigate the effect of c9, t11-conjugated linoleic acid (c9,t11-CLA) on the adhesion of human gastric carcinoma cell line (SGC-7901).METHODS: SGC-7901 cells were at first treated with different concentrations (25, 50, 100, 200 μmol/L) of c9,t111-CLA and 1 mL/L ethanol (as a negative control) for 24 h.Using adhesion assay and Western blot, we investigated the ability of SGC-7901 cells to adhere to intracellular matrix and examined the expression of E-cadherin (ECD), α-catenin,intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in these cells.RESULTS: The attachment rate to laminin of SGC-7901 cells treated with different concentrations of c9,t11-CLA (0,25, 50, 100, and 200 μmol/L) was 100.0±3.3, 95.7±4.0,89.2±4.6, 87.9±6.1, and 65.9±5.8, respectively. The attachment rate to fibronectin was 100.0±4.7, 96.8±3.8,94.5±4.1, 76.5±4.3, and 61.8±4.8, respectively. The attachment rate to Matrigel was 99.9±6.6, 91.4±6.8,85.5±7.4, 79.3±5.6, and 69.6±5.1, respectively. Besides,c9,t11-CLA could increase the level of ECD and α-catenin,and decrease the level of ICAM-1 and VCAM-1 in SGC-7901 cells.CONCLUSION: c9, t11-CLA can reduce the adhesion of human gastric carcinoma cells to laminin, fibronectin and Matrigel. c9,t11-CLA can increase the level of ECD and α-catenin, and decrease the level of ICAM-1 and VCAM-1 in human gastric carcinoma cells.
文摘Trichoderma harzianum strain T22 controls various diseases of maize and other crops, including seedling and root rots caused by Pythium ultimum. Seedlings of inbred line Mo17 were grown from T22-treated or untreated seeds in field soil or in field soil intested with the pathogen. Five days after planting, seedlings of Mo17 (5-days-old) were smaller in the presence of P. ultimum and larger in the presence of T22 relative to the control. The combination of T22 with P. ultimum (T22+ P. ultimum ) resulted in plants as large as T22 alone. Methods for protein extraction and 2-D gel electrophoresis were developed. Proteins in seedlings roots from the various treatments were separated on 2-D gels and analyzed using PDQuest TM. 2-D software. With seedlings produced from T22-treated seeds, there were 104 unmatched proteins and 164 matched proteins relative to the control, and 97 and 150 from the treatment with T22+ P. ultimum, respectively, however, with P. ultimum alone the numbers were much lower than above two treatments. Comparatively, there was very lower similarity of proteome patterns of seedling roots with T22 or P. ultimum or both to control seedlings, the correlative coefficient values were 0.72, 0.51 and 0.49 for the comparisons among control with T22, P. ultimum and T22+ P. ultimum, respectively. Moreover, correlative coefficient of proteome patterns between T22 with P. ultimum was only 0.65, and T22 fungal proteome were also not same as any one of seedling roots with various treatments. Taken together, the components in seedling root proteome seemed to be mostly coming from Mo17 plants themselves and affected strongly by either microbes, but the effects appeared to be stronger by P. ultimum than by T22. 41 spots were selected for protein mass fingerprinting identification, and most detected-spots were intensified in abundance by T22 or T22+ P.ultimum treatments such as pathogenesis-related protein and endochitnase etc. SOD (Mn) was found to be involved in the defensive reaction of host against P. ultimum because the protein only appeared in the treatment with T22 or T22+ P.ultimum. Besides, some proteins associated with host respiration, nutrition synthesis and transport appeared to be in coordination with defensive-related proteins against the damping off.
文摘Three genes encoding for fungal cell wall degrading enzymes (CWDE), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations. The coding sequences were placed downstream of the rice actin promoter and all vectors were used to transform rice plants. A total of more than 1,800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. Expression in plant was obtained for all the fungal genes used singly or in combinations. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had a lesser effect. The expression level of endochitinase but not of the exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the positive effect of endochitinase on disease resistance when two genes were co-expressed in transgenic rice. Improved resistance to Magnaporthe grisea was found in all types of regenerated plants, including those with the gluc78 gene alone, while a few lines expressing either ech42 or nag70 appeared to be immune to this pathogen. Transgenic plants expressing the gluc78 gene alone were stunted and only few of them survived, even though they showed resistance to M. grisea. However, combination with either one of the two other genes (ech42, nag70) as included in the same T-DNA region, reduced the negative effect of gluc78 on plant growth. This is the first report of single or multiple of expression of transgens encoding CWDEs that results in resistance to blast and sheath blight in rice.
基金This work was supported by the National Science Foundation(Grant DMR-9812351)
文摘The structure type for the crystal of 4,4'-bis-(2-hydroxy-ethoxyl)-biphenyl 1 has been predicted by using the previously developed interfacial model for small organic molecules. Based on the calculated hydrophobic to hydrophilic volume of 1, this model predicts the crystal structure to be of lamellar or bicontinuous type, which has been confirmed by the X-ray single-crystal structure analysis (C20H26O6, monoclinic, P21/C, a = 16.084(1), b = 6.0103(4), c = 9.6410(7) A, β9 = 103.014(2)°, V= 908.1(1) A3, Z = 2, Dc= 1.325 g/cm3, F(000)=388,μ = 0.097 mm-1, MoKα radiation, λ = 0.71073 A, R = 0.0382 and wR = 0.0882 with I > 2σ(I) for 7121 reflections collected, 1852 unique reflections and 170 parameters). As predicted, the hydrophobic and hydrophilic portions of 1 form in the lamellae. The same interfacial model is applied to other amphilphilic small molecule organic systems for structural type prediction.
