Many genes encoding CCT domain-containing proteins regulate flowering time. In rice(Oryza sativa), 41 such genes have been identified, but only a few have been shown to regulate heading date. Here, to test whether and...Many genes encoding CCT domain-containing proteins regulate flowering time. In rice(Oryza sativa), 41 such genes have been identified, but only a few have been shown to regulate heading date. Here, to test whether and how additional CCT family genes regulate heading date in rice, we classified these genes into five groups based on their diurnal expression patterns. The expression patterns of genes in the same subfamily or in close phylogenetic clades tended to be similar. We generated knockout mutants of the entire gene family via CRISPR/Cas9. The heading dates of knockout mutants of only 4 of 14 genes previously shown to regulate heading date were altered, pointing to functional redundancy of CCT family genes in regulating this trait. Analysis of mutants of four other genes showed that OsCCT22, OsCCT38, and OsCCT41 suppress heading under long-day conditions and promote heading under short-day conditions. OsCCT03 promotes heading under both conditions and upregulates the expression of Hd1 and Ehd1, a phenomenon not previously reported for other such genes. To date, at least 18 CCT domaincontaining genes involved in regulating heading have been identified, providing diverse, flexible gene combinations for generating rice varieties with a given heading date.展开更多
Effect of the specific gene knockout on the main metabolism in Escherichia coli was reviewed, and the regulation mechanisms were clarified based on different levels of information such as gene expressions, enzyme acti...Effect of the specific gene knockout on the main metabolism in Escherichia coli was reviewed, and the regulation mechanisms were clarified based on different levels of information such as gene expressions, enzyme activities, intracellular metabolite concentrations, and metabolic fluxes together with fermentation data. The effects of the knockout of such genes as pflA, pta, ppc, pykF, adhE, and ldhA on the metabolic changes were analyzed for the case under anaerobic condition. The effects of the knockout of such genes as pgi, zwf, gnd, ppc pck, pyk, and lpdA on the metabolic changes were also analyzed for the case under aerobic condition. The metabolic regulation analysis was made focusing on the roles of transcription factors.展开更多
Magnaporthe oryzae,the causal agent of rice blast,induces significant upregulation of OsPR10b,a pathogenesis-related(PR)pollen allergen(BetV-1)family gene.To investigate its role in immunity,we generated OsPR10b knock...Magnaporthe oryzae,the causal agent of rice blast,induces significant upregulation of OsPR10b,a pathogenesis-related(PR)pollen allergen(BetV-1)family gene.To investigate its role in immunity,we generated OsPR10b knockout mutants in the Zhonghua 11(ZH11)background.OsPR10b was predominantly expressed in rice calli and strongly induced by M.oryzae infection.Knockout mutants(ospr10b-1 and ospr10b-2)exhibited heightened susceptibility to both M.oryzae and Xanthomonas oryzae pv.oryzae(Xoo),demonstrating that OsPR10b positively regulates resistance to blast and bacterial blight.Our findings elucidate OsPR10b’s role in rice immunity and provide genetic resources for disease-resistant breeding.展开更多
AIM: To determine whether efflux systems contribute to multidrug resistance of H pylori. METHODS: A chloramphenicol-induced multidrug resistance model of six susceptible H pylori strains (5 isolates and H pylori NCTC1...AIM: To determine whether efflux systems contribute to multidrug resistance of H pylori. METHODS: A chloramphenicol-induced multidrug resistance model of six susceptible H pylori strains (5 isolates and H pylori NCTC11637) was developed. Multidrug-resistant (MDR) strains were selected and the minimal inhibitory concentration (MIC) of eryth-romycin, metronidazole, penicillin G, tetracycline, and ciprofloxacin in multidrug resistant strains and their parent strains was determined by agar dilution tests. The level of mRNA expression of hefA was assessed by fluorescence real-time quantitative PCR. A H pylori LZ1026 knockout mutant (ΔH pylori LZ1026) for (puta-tive) efflux protein was constructed by inserting the kanamycin resistance cassette from pEGFP-N2 into hefA, and its susceptibility profiles to 10 antibiotics were evaluated. RESULTS: The MIC of six multidrug-resistant strains (including 5 clinical isolates and H pylori NCTC11637) increased signifi cantly (≥ 4-fold) compared with their parent strains. The expression level of hefA gene was significantly higher in the MDR strains than in their parent strains (P = 0.033). A H pylori LZ1026 mutant was successfully constructed and the ΔH pylori LZ1026 was more susceptible to four of the 10 antibiotics. All the 20 strains displayed transcripts for hefA that con-fi rmed the in vitro expression of these genes.CONCLUSION: The efflux pump gene hefA plays an important role in multidrug resistance of H pylori.展开更多
基金This study was supported by the National Special Program for Research of Transgenic Plants of China(2011ZX08009-001-002)the National Natural Science Foundation of China(31701054)the Natural Science Foundation of Jiangxi Province(20192BAB214013)。
文摘Many genes encoding CCT domain-containing proteins regulate flowering time. In rice(Oryza sativa), 41 such genes have been identified, but only a few have been shown to regulate heading date. Here, to test whether and how additional CCT family genes regulate heading date in rice, we classified these genes into five groups based on their diurnal expression patterns. The expression patterns of genes in the same subfamily or in close phylogenetic clades tended to be similar. We generated knockout mutants of the entire gene family via CRISPR/Cas9. The heading dates of knockout mutants of only 4 of 14 genes previously shown to regulate heading date were altered, pointing to functional redundancy of CCT family genes in regulating this trait. Analysis of mutants of four other genes showed that OsCCT22, OsCCT38, and OsCCT41 suppress heading under long-day conditions and promote heading under short-day conditions. OsCCT03 promotes heading under both conditions and upregulates the expression of Hd1 and Ehd1, a phenomenon not previously reported for other such genes. To date, at least 18 CCT domaincontaining genes involved in regulating heading have been identified, providing diverse, flexible gene combinations for generating rice varieties with a given heading date.
文摘Effect of the specific gene knockout on the main metabolism in Escherichia coli was reviewed, and the regulation mechanisms were clarified based on different levels of information such as gene expressions, enzyme activities, intracellular metabolite concentrations, and metabolic fluxes together with fermentation data. The effects of the knockout of such genes as pflA, pta, ppc, pykF, adhE, and ldhA on the metabolic changes were analyzed for the case under anaerobic condition. The effects of the knockout of such genes as pgi, zwf, gnd, ppc pck, pyk, and lpdA on the metabolic changes were also analyzed for the case under aerobic condition. The metabolic regulation analysis was made focusing on the roles of transcription factors.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest of Fujian Province,China(Grant No.2023R1021006)the National Natural Science Foundation of China(Grant No.32402387)+1 种基金the extended research project of the National Natural Science Foundation of China(Grant No.GJYS202511)the 5511 Collaborative Engineering Project,China(Grant No.XTCXGC2021001).
文摘Magnaporthe oryzae,the causal agent of rice blast,induces significant upregulation of OsPR10b,a pathogenesis-related(PR)pollen allergen(BetV-1)family gene.To investigate its role in immunity,we generated OsPR10b knockout mutants in the Zhonghua 11(ZH11)background.OsPR10b was predominantly expressed in rice calli and strongly induced by M.oryzae infection.Knockout mutants(ospr10b-1 and ospr10b-2)exhibited heightened susceptibility to both M.oryzae and Xanthomonas oryzae pv.oryzae(Xoo),demonstrating that OsPR10b positively regulates resistance to blast and bacterial blight.Our findings elucidate OsPR10b’s role in rice immunity and provide genetic resources for disease-resistant breeding.
文摘AIM: To determine whether efflux systems contribute to multidrug resistance of H pylori. METHODS: A chloramphenicol-induced multidrug resistance model of six susceptible H pylori strains (5 isolates and H pylori NCTC11637) was developed. Multidrug-resistant (MDR) strains were selected and the minimal inhibitory concentration (MIC) of eryth-romycin, metronidazole, penicillin G, tetracycline, and ciprofloxacin in multidrug resistant strains and their parent strains was determined by agar dilution tests. The level of mRNA expression of hefA was assessed by fluorescence real-time quantitative PCR. A H pylori LZ1026 knockout mutant (ΔH pylori LZ1026) for (puta-tive) efflux protein was constructed by inserting the kanamycin resistance cassette from pEGFP-N2 into hefA, and its susceptibility profiles to 10 antibiotics were evaluated. RESULTS: The MIC of six multidrug-resistant strains (including 5 clinical isolates and H pylori NCTC11637) increased signifi cantly (≥ 4-fold) compared with their parent strains. The expression level of hefA gene was significantly higher in the MDR strains than in their parent strains (P = 0.033). A H pylori LZ1026 mutant was successfully constructed and the ΔH pylori LZ1026 was more susceptible to four of the 10 antibiotics. All the 20 strains displayed transcripts for hefA that con-fi rmed the in vitro expression of these genes.CONCLUSION: The efflux pump gene hefA plays an important role in multidrug resistance of H pylori.
