[Objective] The 15urpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze th...[Objective] The 15urpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze the physiological characteristics of two Arabidopsis mu- tants and their wild type. [Result] There existed distinct differences in stomata apertures, water loss and leaf temperature compared with wild type except for stomata density. In addition, seed germination test on the medium indicated that cdfl was insensitive to ABA, mannitol and NaCI, but cdsl performed contrary to cdil. [ Conclusion] There are some different physiological characteristics between wild type and mutants.展开更多
A high_CO 2_requiring mutant of Synechococcus sp. PCC7942 has been isolated after chemical mutagenesis of ethyl methane sulphonate (EMS). It was able to grow at 4% CO 2, but not under ambient CO 2. The initial s...A high_CO 2_requiring mutant of Synechococcus sp. PCC7942 has been isolated after chemical mutagenesis of ethyl methane sulphonate (EMS). It was able to grow at 4% CO 2, but not under ambient CO 2. The initial screening of the mutant showed that the genetic reversion rate was about 10 -7 and death occurred 2-3 days after being transferred from 4% CO 2 to the ambient air. Its photosynthetic dependence on external dissolved inorganic carbon was higher than that of the wild type cells, but its carbonic anhydrase activity was comparatively low. In the ultrastructural level, various types of aberrant carboxysomes appeared in the mutant cells: rod_shaped carboxysomes, irregular carboxysomes and the “empty_inclusion carboxysomes" with increasing number of glycogen granules surrounding the thylakoids. All these alterations indicated that the mutant was defective in utilizing the external CO 2. The induction of carboxysomes by lower levels of CO 2 and the biogenesis of carboxysomes are herein discussed.展开更多
[Objective] This study aimed to investigate the action of mutant gene o2 and its effect on nutritional quality of different maize combinations. [Method] A total of 33 normal maize combinations from 18 inbred lines wer...[Objective] This study aimed to investigate the action of mutant gene o2 and its effect on nutritional quality of different maize combinations. [Method] A total of 33 normal maize combinations from 18 inbred lines were compared with 33 combinations including gene o2 from the corresponding o2 near-isogenic lines （o2-NILs）, to study the effect of o2 gene introduction on maize grain quality. [Result] The contents of lysine, protein and oil in o2-NILs were greatly more than that of normal maize combinations. Except for lysine, contents of other 14 amino acids changed when o2 gene was introduced. Contents of aspartic acid, threonine, glycine, isoleucine, histidine, arginine and proline were improved; while contents of serine, glutamic acid, alanine, valine, leucine, tyrosine and phenylalanine were decreased. Correlation analysis showed that contents of aspartic acid, arginine and threonine had the highest correlation with lysine content. Protein and oil contents had higher correlation with lysine content （0.48 and 0.38）. Analysis of 33 o2-NILs revealed that the o2 combinations CAL58×Ji477and CA156×196 showed high comprehensive quality and high yield with greater development potential. [Conclusion] This study will provide theoretical and material basis for improving the quality of temperate maize germplasm by introducing o2 gene.展开更多
To obtain thermotolerant mutants of G. oxydans, which can enhance the transformation rate of L-sorbose to 2-Keto-L-gulonate （2-KLG） at 33℃ in a two-step process of vitamin C manufacture, ion beam was used as a muta...To obtain thermotolerant mutants of G. oxydans, which can enhance the transformation rate of L-sorbose to 2-Keto-L-gulonate （2-KLG） at 33℃ in a two-step process of vitamin C manufacture, ion beam was used as a mutation source. Gluconobacter oxydans GO and Bacillus megaterium B0 were used in this study. The original strain Gluconobacter oxydans GO was mutated by the heavy ion implantation facility at the Institute of Plasma Physics, Chinese Academy of Sciences. Several mutants including Gluconobacter oxydans GI13 were isolated and cocultured with Bacillus megaterium B0 at 33℃ in shaking flasks. The average transformation rate of the new mixed strain GI13-B0 in per gram-molecule reached 94.4% after seven passages in shaking flasks, which was increased by 7% when compared with the original mixed strain G0-B0 （Gluconobacter oxydans GO and Bacillus megaterium B0）. Moreover, the transformation rate of I13B0 was stable at 94% at temperatures ranging from 25℃ to 33℃, which would be of much value in reducing energy consumption in the manufacture of L-ascorbic acid, especially in the season of summer. To clarify some mechanism of the mutation, the specific activities of L-sorbose dehydrogenase in both GO and GI13 were estimated.展开更多
The biodegradations of phenol and 4-chlorophenol （4-cp） were studied using the mutant strain CTM 2 obtained by the He-Ne laser irradiation on wild-type Candida tropicalis. The results showed that the capacity of the...The biodegradations of phenol and 4-chlorophenol （4-cp） were studied using the mutant strain CTM 2 obtained by the He-Ne laser irradiation on wild-type Candida tropicalis. The results showed that the capacity of the CTM 2 to biodegrade 4-cp was increased up to 400 mg·L^-1 within 59.5 h. In the dual-substrate biodegradation both velocity and capacity of the CTM 2 to degrade 4-cp increased with low-concentration phenol. A totalof 400 mg·L^-1 4-cp was completely degraded within 50.＇5 h in thepresence of 300 mg·L^-1 phenol. The maximum 4：cp biodegegradation could reach 440 mg·L^1 with 120 mg·L^1 phenol. Low-concentration 4-cp caused great inhibition on the CTM 2 to degrade phenol. In addition, the kinetic behaviors were described using the kinetic model proposed in this lab.展开更多
As a kind of mutagen, ion beam irradiation can create abundant biological mutations. A population of about 2000 lines was generated by irradiating dry wheat seeds of XiaoYan 81 with low-energy nitrogen ion beams. The ...As a kind of mutagen, ion beam irradiation can create abundant biological mutations. A population of about 2000 lines was generated by irradiating dry wheat seeds of XiaoYan 81 with low-energy nitrogen ion beams. The traits of the plant, such as height, spike type, fertility, stem color and awn length, were investigated. The mutation rate in terms of the plant height in M2 was 2.9%. Eighteen deletion mutants of TaGA2ox1 were obtained. Associate analysis showed that TaGA2ox1 was closely related to the plant height. Most of the TaGA2ox1-deleted mutants were higher than the control, suggesting that the biological function of TaGA2ox1 is similar to its homologues in other plants. These results demonstrate that ion beam irradiation is an efficient tool in the construction of a mutant library for wheat.展开更多
[Objectives]The CRISPR/Cas9(Clustered regulatory interspaced short palindromic repeat/Cas9)gene editing technology is the third generation of"genome fixed-point editing technology"following the"zinc fin...[Objectives]The CRISPR/Cas9(Clustered regulatory interspaced short palindromic repeat/Cas9)gene editing technology is the third generation of"genome fixed-point editing technology"following the"zinc finger endonuclease(ZFN)"and"transcription activator effector nuclease(TALEN)".Glucotransferase genes UGT84A2 and UGT84A4,can simultaneously convert hydroxycinnamate into 1-O-β-glucose esters as isozymes.The CRISPR/Cas9 technology was used to construct double mutants of Arabidopsis thaliana ugt84a2/ugt84a4.[Methods]A CRISPR/Cas9 double mutant expression vector was constructed using UGT84A2 and UGT84A4 as the target genes.The Agrobacterium-mediated dip dyeing method was used to transform wild-type A.thaliana,and the CRISPR/Cas9system was used to target and knock out A.thaliana UGT84A2 and UGT84A4 genes.[Results]The descendants of A.thaliana with the UGT84A2/UGT84A4 gene were sequenced and analyzed.Thirteen positively transformed plants obtained were analyzed according to the sequencing results,and the ugt84a2/ugt84a4 double mutants were screened.[Conclusions]This study provides a reference for the functional study of UGT84A2 and UGT84A4 isoenzyme genes in other species,as well as strong theoretical and method support for accelerating the development and utilization of UGT84A2/UGT84A4 functional gene resources.展开更多
A new chemically mutagenic mutant of Synechococcus PCC7942 named high-CO2 re-quiring mutant, which could grow at 4% CO2 but could not grow at air levels of CO2, was isolated. Com-parative studies on some physiological...A new chemically mutagenic mutant of Synechococcus PCC7942 named high-CO2 re-quiring mutant, which could grow at 4% CO2 but could not grow at air levels of CO2, was isolated. Com-parative studies on some physiological aspects of the mutant and high-cO2 growing cells (growing at 4%CO2 ) were conducted. The result showed that the mutant had lower growing rate, about 1/40th photosyn-thetic affinity to inorganic carbon, 25% lower carbonic anhydrase (CA) activity, lower quenching rate ofchlorophyll fluoresence, and about 1/2 alkalinization rate of the medium. The CA activity responses ofthe two types of cells to different concentrations of CO2 were determined. Upon the addition of inorganiccarbon (Ci), the rate of active Ci uptake described by the rate of chlorophyll fluorescence quenching ofthe mutant was obviously lower compared with that of the high-CO2 growing cells; the size of the internalinorganic carbon pool size determined by the extent of fluorescence quenching Of the mutant was alsosmaller.展开更多
文摘[Objective] The 15urpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze the physiological characteristics of two Arabidopsis mu- tants and their wild type. [Result] There existed distinct differences in stomata apertures, water loss and leaf temperature compared with wild type except for stomata density. In addition, seed germination test on the medium indicated that cdfl was insensitive to ABA, mannitol and NaCI, but cdsl performed contrary to cdil. [ Conclusion] There are some different physiological characteristics between wild type and mutants.
文摘A high_CO 2_requiring mutant of Synechococcus sp. PCC7942 has been isolated after chemical mutagenesis of ethyl methane sulphonate (EMS). It was able to grow at 4% CO 2, but not under ambient CO 2. The initial screening of the mutant showed that the genetic reversion rate was about 10 -7 and death occurred 2-3 days after being transferred from 4% CO 2 to the ambient air. Its photosynthetic dependence on external dissolved inorganic carbon was higher than that of the wild type cells, but its carbonic anhydrase activity was comparatively low. In the ultrastructural level, various types of aberrant carboxysomes appeared in the mutant cells: rod_shaped carboxysomes, irregular carboxysomes and the “empty_inclusion carboxysomes" with increasing number of glycogen granules surrounding the thylakoids. All these alterations indicated that the mutant was defective in utilizing the external CO 2. The induction of carboxysomes by lower levels of CO 2 and the biogenesis of carboxysomes are herein discussed.
基金Supported by Beijing Municipal Natural Science Foundation (6112003)~~
文摘[Objective] This study aimed to investigate the action of mutant gene o2 and its effect on nutritional quality of different maize combinations. [Method] A total of 33 normal maize combinations from 18 inbred lines were compared with 33 combinations including gene o2 from the corresponding o2 near-isogenic lines （o2-NILs）, to study the effect of o2 gene introduction on maize grain quality. [Result] The contents of lysine, protein and oil in o2-NILs were greatly more than that of normal maize combinations. Except for lysine, contents of other 14 amino acids changed when o2 gene was introduced. Contents of aspartic acid, threonine, glycine, isoleucine, histidine, arginine and proline were improved; while contents of serine, glutamic acid, alanine, valine, leucine, tyrosine and phenylalanine were decreased. Correlation analysis showed that contents of aspartic acid, arginine and threonine had the highest correlation with lysine content. Protein and oil contents had higher correlation with lysine content （0.48 and 0.38）. Analysis of 33 o2-NILs revealed that the o2 combinations CAL58×Ji477and CA156×196 showed high comprehensive quality and high yield with greater development potential. [Conclusion] This study will provide theoretical and material basis for improving the quality of temperate maize germplasm by introducing o2 gene.
基金supported by the National Major Technologies R&D Program of China during the 10th Five-Year Plan Period (No. 2001BA302B)
文摘To obtain thermotolerant mutants of G. oxydans, which can enhance the transformation rate of L-sorbose to 2-Keto-L-gulonate （2-KLG） at 33℃ in a two-step process of vitamin C manufacture, ion beam was used as a mutation source. Gluconobacter oxydans GO and Bacillus megaterium B0 were used in this study. The original strain Gluconobacter oxydans GO was mutated by the heavy ion implantation facility at the Institute of Plasma Physics, Chinese Academy of Sciences. Several mutants including Gluconobacter oxydans GI13 were isolated and cocultured with Bacillus megaterium B0 at 33℃ in shaking flasks. The average transformation rate of the new mixed strain GI13-B0 in per gram-molecule reached 94.4% after seven passages in shaking flasks, which was increased by 7% when compared with the original mixed strain G0-B0 （Gluconobacter oxydans GO and Bacillus megaterium B0）. Moreover, the transformation rate of I13B0 was stable at 94% at temperatures ranging from 25℃ to 33℃, which would be of much value in reducing energy consumption in the manufacture of L-ascorbic acid, especially in the season of summer. To clarify some mechanism of the mutation, the specific activities of L-sorbose dehydrogenase in both GO and GI13 were estimated.
基金Supported by the science and Technology Innovative Talents Foundation of China （2006RFQXS070）, the Youth Academic Cadreman Project of Heilongjiang Province （1152G068）, Scientific Research Fund of Heilongjiang Province （11523063） and the Science Foundation for Post Doctorate of China （20070410268）.
文摘The biodegradations of phenol and 4-chlorophenol （4-cp） were studied using the mutant strain CTM 2 obtained by the He-Ne laser irradiation on wild-type Candida tropicalis. The results showed that the capacity of the CTM 2 to biodegrade 4-cp was increased up to 400 mg·L^-1 within 59.5 h. In the dual-substrate biodegradation both velocity and capacity of the CTM 2 to degrade 4-cp increased with low-concentration phenol. A totalof 400 mg·L^-1 4-cp was completely degraded within 50.＇5 h in thepresence of 300 mg·L^-1 phenol. The maximum 4：cp biodegegradation could reach 440 mg·L^1 with 120 mg·L^1 phenol. Low-concentration 4-cp caused great inhibition on the CTM 2 to degrade phenol. In addition, the kinetic behaviors were described using the kinetic model proposed in this lab.
基金supported by National Natural Science Foundation of China (No.30800204)Chinese Ministry of Agriculture supported by the Open Project of the Chinese Academy of Sciences
文摘As a kind of mutagen, ion beam irradiation can create abundant biological mutations. A population of about 2000 lines was generated by irradiating dry wheat seeds of XiaoYan 81 with low-energy nitrogen ion beams. The traits of the plant, such as height, spike type, fertility, stem color and awn length, were investigated. The mutation rate in terms of the plant height in M2 was 2.9%. Eighteen deletion mutants of TaGA2ox1 were obtained. Associate analysis showed that TaGA2ox1 was closely related to the plant height. Most of the TaGA2ox1-deleted mutants were higher than the control, suggesting that the biological function of TaGA2ox1 is similar to its homologues in other plants. These results demonstrate that ion beam irradiation is an efficient tool in the construction of a mutant library for wheat.
基金Supported by Natural Science Foundation of Shandong Province(ZR2017PC007)Project of Shandong(Linyi)Institute of Modern Agriculture of Zhejiang University for Serving Local Economic Development(ZDNY-2020-FWLY02007)Doctoral Program of China West Normal University(18Q051)。
文摘[Objectives]The CRISPR/Cas9(Clustered regulatory interspaced short palindromic repeat/Cas9)gene editing technology is the third generation of"genome fixed-point editing technology"following the"zinc finger endonuclease(ZFN)"and"transcription activator effector nuclease(TALEN)".Glucotransferase genes UGT84A2 and UGT84A4,can simultaneously convert hydroxycinnamate into 1-O-β-glucose esters as isozymes.The CRISPR/Cas9 technology was used to construct double mutants of Arabidopsis thaliana ugt84a2/ugt84a4.[Methods]A CRISPR/Cas9 double mutant expression vector was constructed using UGT84A2 and UGT84A4 as the target genes.The Agrobacterium-mediated dip dyeing method was used to transform wild-type A.thaliana,and the CRISPR/Cas9system was used to target and knock out A.thaliana UGT84A2 and UGT84A4 genes.[Results]The descendants of A.thaliana with the UGT84A2/UGT84A4 gene were sequenced and analyzed.Thirteen positively transformed plants obtained were analyzed according to the sequencing results,and the ugt84a2/ugt84a4 double mutants were screened.[Conclusions]This study provides a reference for the functional study of UGT84A2 and UGT84A4 isoenzyme genes in other species,as well as strong theoretical and method support for accelerating the development and utilization of UGT84A2/UGT84A4 functional gene resources.
文摘A new chemically mutagenic mutant of Synechococcus PCC7942 named high-CO2 re-quiring mutant, which could grow at 4% CO2 but could not grow at air levels of CO2, was isolated. Com-parative studies on some physiological aspects of the mutant and high-cO2 growing cells (growing at 4%CO2 ) were conducted. The result showed that the mutant had lower growing rate, about 1/40th photosyn-thetic affinity to inorganic carbon, 25% lower carbonic anhydrase (CA) activity, lower quenching rate ofchlorophyll fluoresence, and about 1/2 alkalinization rate of the medium. The CA activity responses ofthe two types of cells to different concentrations of CO2 were determined. Upon the addition of inorganiccarbon (Ci), the rate of active Ci uptake described by the rate of chlorophyll fluorescence quenching ofthe mutant was obviously lower compared with that of the high-CO2 growing cells; the size of the internalinorganic carbon pool size determined by the extent of fluorescence quenching Of the mutant was alsosmaller.
