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
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
Plant class III heme peroxidases catalyze lignin polymerization. Previous reports have shown that at least three Arabidopsis thaliana peroxidases, AtPrx2, AtPrx25 and AtPrx71, are involved in stem lignification using ...Plant class III heme peroxidases catalyze lignin polymerization. Previous reports have shown that at least three Arabidopsis thaliana peroxidases, AtPrx2, AtPrx25 and AtPrx71, are involved in stem lignification using T-D NA insertion mutants, atprx2, atprx25, and atprx71. Here, we generated three double mutants, atprx2/atprx25, atprx2/atprx71, and atprx25/atprx71, and investigated the impact of the simultaneous deficiency of these peroxidases on lignins and plant growth. Stem tissue analysis using the acetyl bromide method and derivatization followed by reductive cleavage revealed improved lignin characteristics, such as lowered lignin content and increased arylglycerol-β-aryl （β-O-4） linkage type, especially β-O-4 linked syringyl units, in lignin, supporting the roles of these genes in lignin polymerization. In addition, none of the double mutants oexhibited severe growth defects, such as shorter plant stature, dwarfing, or sterility, and their stems had improved ceil wall degradability. This study will contribute to progress in lignin bioengineering to improve iignocellulosic biomass.展开更多
The pistil, the female reproductive organ of plants, is a key player in the success of sexual plant reproduction. Ultimately, the production of fruits and seeds depends on the proper pistil development and function. T...The pistil, the female reproductive organ of plants, is a key player in the success of sexual plant reproduction. Ultimately, the production of fruits and seeds depends on the proper pistil development and function. Therefore, the identification and characterization of pistil expressed genes is essential for a better understanding and manipulation of the plant reproduction process. For studying the function of pistil expressed genes, transgenic and/or mutant plants for the genes of interest are used. The present article provides a review of methods already exploited to analyze sexual reproductive success. We intend to supply useful information and to guide future experiments in the study of genes affecting pistil development and function.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.
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.
基金supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Scientific Research (B) Grant Number 26292097 (Y.T.)JSPS KAKENHI Exploratory Research Grant Number 25660140 (Y.T.)JSPS KAKENHI Young Scientists (B) Grant Number 25850123 (J.S.)
文摘Plant class III heme peroxidases catalyze lignin polymerization. Previous reports have shown that at least three Arabidopsis thaliana peroxidases, AtPrx2, AtPrx25 and AtPrx71, are involved in stem lignification using T-D NA insertion mutants, atprx2, atprx25, and atprx71. Here, we generated three double mutants, atprx2/atprx25, atprx2/atprx71, and atprx25/atprx71, and investigated the impact of the simultaneous deficiency of these peroxidases on lignins and plant growth. Stem tissue analysis using the acetyl bromide method and derivatization followed by reductive cleavage revealed improved lignin characteristics, such as lowered lignin content and increased arylglycerol-β-aryl （β-O-4） linkage type, especially β-O-4 linked syringyl units, in lignin, supporting the roles of these genes in lignin polymerization. In addition, none of the double mutants oexhibited severe growth defects, such as shorter plant stature, dwarfing, or sterility, and their stems had improved ceil wall degradability. This study will contribute to progress in lignin bioengineering to improve iignocellulosic biomass.
基金Supported by grants from Fundao de Amparo à Pesquisa no Estado de So Paulo – Brazil(FAPESP no. 06/54431-9)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) – Brazil. CPG Calixto was supported by a fellowship from FAPESP.
文摘The pistil, the female reproductive organ of plants, is a key player in the success of sexual plant reproduction. Ultimately, the production of fruits and seeds depends on the proper pistil development and function. Therefore, the identification and characterization of pistil expressed genes is essential for a better understanding and manipulation of the plant reproduction process. For studying the function of pistil expressed genes, transgenic and/or mutant plants for the genes of interest are used. The present article provides a review of methods already exploited to analyze sexual reproductive success. We intend to supply useful information and to guide future experiments in the study of genes affecting pistil development and function.
