[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determinati...[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determination of growth curve and correlation curve between OD 600 values and viable counts,drug susceptibility tests,pathogenicity analysis,and histopathological observations were carried out.[Results]The Streptococcus strain isolated from infected pigs was identified as Streptococcus suis type 2,which was named TA01 strain.TA01 strain reached the growth peak at 6-8 h post-incubation,and viable counts gradually declined after 8 h of incubation.The correlation equation between OD 600 values and viable counts is y=24.659 x-1.076 1,R^2=0.996 7.TA01 strain was sensitive to penicillin,erythromycin,florfenicol and oxacillin,and resistant to ciprofloxacin,polymyxin B and clindamycin.According to the results of pathogenicity analysis,all the mice in 3.6×10^9 cfu/mouse group died within 48,and these dead mice exhibited acute pyaemia septica.Based on the Reed-Muench formula,it was calculated that LD 50 of TA01 strain was 1.137×10^8 cfu/mouse.Pathological examination showed obvious blue-stained bacteria clusters,accompanied by neutrophil infiltration.[Conclusions]TA01 strain was a virulent strain of Streptococcus suis type 2.Compared with Streptococcus strains which were isolated and reported in China,TA01 strain exhibited strong virulence and rapid proliferation.展开更多
The essential role of ethylene in fruit ripening has been thoroughly studied.However,the involvement of brassinosteroids(BRs)in the regulation of fruit ripening and their relationship with the ethylene pathway are poo...The essential role of ethylene in fruit ripening has been thoroughly studied.However,the involvement of brassinosteroids(BRs)in the regulation of fruit ripening and their relationship with the ethylene pathway are poorly understood.In the current study,we found that BRs were actively synthesized during tomato fruit ripening.We then generated transgenic lines overexpressing or silencing SlCYP90B3,which encodes a cytochrome P450 monooxygenase that catalyzes the rate-limiting step of BR synthesis.The expression level of SlCYP90B3 was positively related to the contents of bioactive BRs as well as the ripening process in tomato fruit,including enhanced softening and increased soluble sugar and flavor volatile contents.Both carotenoid accumulation and ethylene production were strongly correlated with the expression level of SlCYP90B3,corroborated by the altered expression of carotenoid biosynthetic genes as well as ethylene pathway genes in transgenic tomato fruits.However,the application of the ethylene perception inhibitor 1-methycyclopropene(1-MCP)abolished the promotion effect of SlCYP90B3 overexpression on carotenoid accumulation.Taken together,these results increase our understanding of the involvement of SlCYP90B3 in bioactive BR biosynthesis as well as fruit ripening in tomato,thus making SlCYP90B3 a target gene for improvement of visual,nutritional and flavor qualities of tomato fruits with no yield penalty.展开更多
The aim of the study was to investigate the correlation of zinc-finger protein 217 （ZNF217） gone ex- pression with the biological behavior of human ovarian cancer HO-8910 cells. Methods： The expression of ZNF217 in...The aim of the study was to investigate the correlation of zinc-finger protein 217 （ZNF217） gone ex- pression with the biological behavior of human ovarian cancer HO-8910 cells. Methods： The expression of ZNF217 in ovarian carcinoma cell line：s was detected by RT-PCR and Western blot, respectively. The biological behaviors of the transfectants were investigated by MTT, in vitro Boyden chamber and in vivo invasion assay, respectively. Results： RT-PCR and Western blotting revealed that transfection of ZNF217 into the HO-8910 cells significantly increased their proliferation along with mark- edly enhanced in vitro and in vivo invasion and metastatic abilities. MTT assay showed that the proliferation ability of pEGFP- N1-ZNF217/HO-8910 cells was significantly higher than that of pEGFP-N1/HO-8910 cells and HO-8910 cells （P 〈 0.001）. The Boyden chamber assay showed that the numbers of migrating pEGFP-N1-ZNF217/HO-8910, pEGFP-N1/HO-8910 and HO-8910 cells were （141.25 ± 13.91） cells/200 x field, （82.50 ± 11.73） cells/200 × field and （81.75 ± 12.12） cells/200 x field, respectively, with a significant difference between them （F = 29.274, P 〈 0.001）. The nude mouse experiment showed that the in vivo tumor formation ability of pEGFP-N1-ZNF217/HO-8910 cells was significantly higher than that of pEGFP-N1/HO-8910 cells （P 〈 0.001）. Conclusion： Based on these clinical and laboratory observations, we conclude that ZNF217 may contribute to ovarian cancer invasion and metastasis, and associated with worse clinical outcomes. We evaluated ZNF217＇s role as a biomarker of ovarian carcinogenesis and tumor progression in patient samples and explored possible molecular mechanisms in promoting tumor growth and invasion.展开更多
The plant hormone ethylene is essential for climacteric fruit ripening, although it is unclear how other phytohormones and their interactions with ethylene might affect fruit ripening. Here, we explored how brassinost...The plant hormone ethylene is essential for climacteric fruit ripening, although it is unclear how other phytohormones and their interactions with ethylene might affect fruit ripening. Here, we explored how brassinosteroids(BRs) regulate fruit ripening in tomato(Solanum lycopersicum) and how they interact with ethylene. Exogenous BR treatment and increased endogenous BR contents in tomato plants overexpressing the BR biosynthetic gene SlCYP90B3promoted ethylene production and fruit ripening.Genetic analysis indicated that the BR signaling regulators Brassinazole-resistant1(SlBZR1) and BRI1-EMS-suppressor1(SlBES1) act redundantly in fruit softening. Knocking out Sl BZR1 inhibited ripening through transcriptome reprogramming at the onset of ripening. Combined transcriptome deep sequencing and chromatin immunoprecipitation followed by sequencing identified 73 Sl BZR1-repressed targets and 203 Sl BZR1-induced targets involving major ripening-related genes, suggesting that Sl BZR1 positively regulates tomato fruit ripening.Sl BZR1 directly targeted several ethylene and carotenoid biosynthetic genes to contribute to the ethylene burst and carotenoid accumulation to ensure normal ripening and quality formation. Furthermore,knock-out of Brassinosteroid-insensitive2(Sl BIN2),a negative regulator of BR signaling upstream of Sl BZR1, promoted fruit ripening and carotenoid accumulation. Taken together, our results highlight the role of Sl BZR1 as a master regulator of tomato fruit ripening with potential for tomato quality improvement and carotenoid biofortification.展开更多
For adaptation to ever-changing environments,plants have evolved elaborate metabolic systems coupled to a regulatory network for optimal growth and defense. Regulation of plant secondary metabolic pathways such as glu...For adaptation to ever-changing environments,plants have evolved elaborate metabolic systems coupled to a regulatory network for optimal growth and defense. Regulation of plant secondary metabolic pathways such as glucosinolates(GSLs) by defense phytohormones in response to different stresses and nutrient deficiency has been intensively investigated, while how growth-promoting hormone balances plant secondary and primary metabolism has been largely unexplored. Here, we found that growth-promoting hormone brassinosteroid(BR) inhibits GSLs accumulation while enhancing biosynthesis of primary sulfur metabolites, including cysteine(Cys) and glutathione(GSH) both in Arabidopsis and Brassica crops, fine-tuning secondary and primary sulfur metabolism to promote plant growth. Furthermore, we demonstrate that of BRASSINAZOLE RESISTANT 1(BZR1), the central component of BR signaling, exerts distinct transcriptional inhibition regulation on indolic and aliphatic GSL via direct MYB51 dependent repression of indolic GSL biosynthesis, while exerting partial MYB29 dependent repression of aliphatic GSL biosynthesis. Additionally, BZR1 directly activates the transcription of APR1 and APR2 which encodes rate-limiting enzyme adenosine 5′-phosphosulfate reductases in the primary sulfur metabolic pathway.In summary, our findings indicate that BR inhibits the biosynthesis of GSLs to prioritize sulfur usage for primary metabolites under normal growth conditions.These findings expand our understanding of BR promoting plant growth from a metabolism perspective.展开更多
基金Supported by National Key Basic Research Program of China(973 Program)(2017YFD0500605)
文摘[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determination of growth curve and correlation curve between OD 600 values and viable counts,drug susceptibility tests,pathogenicity analysis,and histopathological observations were carried out.[Results]The Streptococcus strain isolated from infected pigs was identified as Streptococcus suis type 2,which was named TA01 strain.TA01 strain reached the growth peak at 6-8 h post-incubation,and viable counts gradually declined after 8 h of incubation.The correlation equation between OD 600 values and viable counts is y=24.659 x-1.076 1,R^2=0.996 7.TA01 strain was sensitive to penicillin,erythromycin,florfenicol and oxacillin,and resistant to ciprofloxacin,polymyxin B and clindamycin.According to the results of pathogenicity analysis,all the mice in 3.6×10^9 cfu/mouse group died within 48,and these dead mice exhibited acute pyaemia septica.Based on the Reed-Muench formula,it was calculated that LD 50 of TA01 strain was 1.137×10^8 cfu/mouse.Pathological examination showed obvious blue-stained bacteria clusters,accompanied by neutrophil infiltration.[Conclusions]TA01 strain was a virulent strain of Streptococcus suis type 2.Compared with Streptococcus strains which were isolated and reported in China,TA01 strain exhibited strong virulence and rapid proliferation.
基金supported by the National Natural Science Foundation of China(Key Program,No.31830078)the Ministry of Agriculture of China(2016ZX08009003-001)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LZ15C150001)the Fundamental Research Funds for the Central University(2020QNA6023).
文摘The essential role of ethylene in fruit ripening has been thoroughly studied.However,the involvement of brassinosteroids(BRs)in the regulation of fruit ripening and their relationship with the ethylene pathway are poorly understood.In the current study,we found that BRs were actively synthesized during tomato fruit ripening.We then generated transgenic lines overexpressing or silencing SlCYP90B3,which encodes a cytochrome P450 monooxygenase that catalyzes the rate-limiting step of BR synthesis.The expression level of SlCYP90B3 was positively related to the contents of bioactive BRs as well as the ripening process in tomato fruit,including enhanced softening and increased soluble sugar and flavor volatile contents.Both carotenoid accumulation and ethylene production were strongly correlated with the expression level of SlCYP90B3,corroborated by the altered expression of carotenoid biosynthetic genes as well as ethylene pathway genes in transgenic tomato fruits.However,the application of the ethylene perception inhibitor 1-methycyclopropene(1-MCP)abolished the promotion effect of SlCYP90B3 overexpression on carotenoid accumulation.Taken together,these results increase our understanding of the involvement of SlCYP90B3 in bioactive BR biosynthesis as well as fruit ripening in tomato,thus making SlCYP90B3 a target gene for improvement of visual,nutritional and flavor qualities of tomato fruits with no yield penalty.
基金Supported by grants from Medical Science and Technology Research Fund of Guangdong Province(No.WSTJJ20111110440104197405153780)the Dean Fund of Nanfang Hospital,Southern Medical University(No.2012B015)
文摘The aim of the study was to investigate the correlation of zinc-finger protein 217 （ZNF217） gone ex- pression with the biological behavior of human ovarian cancer HO-8910 cells. Methods： The expression of ZNF217 in ovarian carcinoma cell line：s was detected by RT-PCR and Western blot, respectively. The biological behaviors of the transfectants were investigated by MTT, in vitro Boyden chamber and in vivo invasion assay, respectively. Results： RT-PCR and Western blotting revealed that transfection of ZNF217 into the HO-8910 cells significantly increased their proliferation along with mark- edly enhanced in vitro and in vivo invasion and metastatic abilities. MTT assay showed that the proliferation ability of pEGFP- N1-ZNF217/HO-8910 cells was significantly higher than that of pEGFP-N1/HO-8910 cells and HO-8910 cells （P 〈 0.001）. The Boyden chamber assay showed that the numbers of migrating pEGFP-N1-ZNF217/HO-8910, pEGFP-N1/HO-8910 and HO-8910 cells were （141.25 ± 13.91） cells/200 x field, （82.50 ± 11.73） cells/200 × field and （81.75 ± 12.12） cells/200 x field, respectively, with a significant difference between them （F = 29.274, P 〈 0.001）. The nude mouse experiment showed that the in vivo tumor formation ability of pEGFP-N1-ZNF217/HO-8910 cells was significantly higher than that of pEGFP-N1/HO-8910 cells （P 〈 0.001）. Conclusion： Based on these clinical and laboratory observations, we conclude that ZNF217 may contribute to ovarian cancer invasion and metastasis, and associated with worse clinical outcomes. We evaluated ZNF217＇s role as a biomarker of ovarian carcinogenesis and tumor progression in patient samples and explored possible molecular mechanisms in promoting tumor growth and invasion.
基金supported by National Natural Science Foundation of China (Key Program 31830078)the Ministry of Agriculture of China (2016ZX08009003-001)+1 种基金Zhejiang Provincial Tenthousand Program for Leading Talents of Science and Technology Innovation (2018R52026)Zhejiang Provincial Natural Science Foundation of China (LZ15C150001)。
文摘The plant hormone ethylene is essential for climacteric fruit ripening, although it is unclear how other phytohormones and their interactions with ethylene might affect fruit ripening. Here, we explored how brassinosteroids(BRs) regulate fruit ripening in tomato(Solanum lycopersicum) and how they interact with ethylene. Exogenous BR treatment and increased endogenous BR contents in tomato plants overexpressing the BR biosynthetic gene SlCYP90B3promoted ethylene production and fruit ripening.Genetic analysis indicated that the BR signaling regulators Brassinazole-resistant1(SlBZR1) and BRI1-EMS-suppressor1(SlBES1) act redundantly in fruit softening. Knocking out Sl BZR1 inhibited ripening through transcriptome reprogramming at the onset of ripening. Combined transcriptome deep sequencing and chromatin immunoprecipitation followed by sequencing identified 73 Sl BZR1-repressed targets and 203 Sl BZR1-induced targets involving major ripening-related genes, suggesting that Sl BZR1 positively regulates tomato fruit ripening.Sl BZR1 directly targeted several ethylene and carotenoid biosynthetic genes to contribute to the ethylene burst and carotenoid accumulation to ensure normal ripening and quality formation. Furthermore,knock-out of Brassinosteroid-insensitive2(Sl BIN2),a negative regulator of BR signaling upstream of Sl BZR1, promoted fruit ripening and carotenoid accumulation. Taken together, our results highlight the role of Sl BZR1 as a master regulator of tomato fruit ripening with potential for tomato quality improvement and carotenoid biofortification.
基金supported by the National Science Foundation of China (31830078, 32172593, and 32202466)Zhejiang Provincial Ten-thousand Program for Leading Talents of Science and Technology Innovation (2018R52026)。
文摘For adaptation to ever-changing environments,plants have evolved elaborate metabolic systems coupled to a regulatory network for optimal growth and defense. Regulation of plant secondary metabolic pathways such as glucosinolates(GSLs) by defense phytohormones in response to different stresses and nutrient deficiency has been intensively investigated, while how growth-promoting hormone balances plant secondary and primary metabolism has been largely unexplored. Here, we found that growth-promoting hormone brassinosteroid(BR) inhibits GSLs accumulation while enhancing biosynthesis of primary sulfur metabolites, including cysteine(Cys) and glutathione(GSH) both in Arabidopsis and Brassica crops, fine-tuning secondary and primary sulfur metabolism to promote plant growth. Furthermore, we demonstrate that of BRASSINAZOLE RESISTANT 1(BZR1), the central component of BR signaling, exerts distinct transcriptional inhibition regulation on indolic and aliphatic GSL via direct MYB51 dependent repression of indolic GSL biosynthesis, while exerting partial MYB29 dependent repression of aliphatic GSL biosynthesis. Additionally, BZR1 directly activates the transcription of APR1 and APR2 which encodes rate-limiting enzyme adenosine 5′-phosphosulfate reductases in the primary sulfur metabolic pathway.In summary, our findings indicate that BR inhibits the biosynthesis of GSLs to prioritize sulfur usage for primary metabolites under normal growth conditions.These findings expand our understanding of BR promoting plant growth from a metabolism perspective.
