Only few glufosinate-tolerant genes,such as phosphinothricin acetyltransferase(PAT)and bialaphos resistance(bar)identified from Streptomyces,are currently available for developing genetically modified rice in agricult...Only few glufosinate-tolerant genes,such as phosphinothricin acetyltransferase(PAT)and bialaphos resistance(bar)identified from Streptomyces,are currently available for developing genetically modified rice in agricultural application.Following the rapid development of genome editing technology,generation of novel glufosinate-tolerant gene resources through artificial evolution of endogenous genes is more promising and highly desirable in rice molecular breeding program.In this study,the endogenous Glutamine synthetase1(OsGS1)was artificially evolved by base-editing-mediated gene evolution(BEMGE)in rice cells to create novel alleles conferring glufosinate tolerance in rice germplasms.Two novel glufosinate-tolerant OsGS1 alleles(OsGS1-AVPS and OsGS1-+AF)and one reported tolerant allele(OsGS1-SGTA)were successfully identified from approximately 4200 independent hygromycin-tolerant calli.Germination assays and spray tests revealed that these three OsGS1 alleles confer glufosinate tolerance in rice.Furthermore,OsGS1-AVPS and OsGS1-SGTA were quickly deployed into the elite rice cultivar Nangeng 46 through precise base editing.Overall,our results demonstrate the feasibility of developing glufosinate-tolerant rice by editing an endogenous rice gene in molecular breeding programs.展开更多
The use of microbes and microbial products as bioherbicides has been studied for several decades, and combinations of bioherbicides and herbicides have been examined to discover possible synergistic interactions to im...The use of microbes and microbial products as bioherbicides has been studied for several decades, and combinations of bioherbicides and herbicides have been examined to discover possible synergistic interactions to improve weed control efficacy. Bioassays were conducted to assess possible interactions of the herbicide glufosinate [2-amino-4-(hydroxymethylphosphinyl) butanoic acid] and Colletotrichum truncatum (CT), a fungal bioherbicide to control hemp sesbania (Sesbania exaltata)]. Glufosinate acts as a glutamine synthetase (GS) inhibitor that causes elevated ammonia levels, but the mode of action of CT is unknown. GS has also been implicated in plant defense in certain plant-pathogen interactions. The effects of spray applications of glufosinate (1.0 mM) orbioherbicide (8.0 × 104 conidia ml-1), applied alone or in combination were monitored (88 h time-course) on seedling growth, GS activity and ammonia levels in hypocotyl tissues under controlled environmental conditions. Growth (elongation and fresh weight) and extractable GS activity were inhibited in tissues by glufosinate and glufosinate plus CT treatments as early as 16 h, but CT treatment did not cause substantial growth reduction or GS inhibition until after ~40 h. Generally, ammonia levels in hemp sesbania tissues under these various treatments were inversely correlated with GS activity. Localization of hemp sesbania GS activity on electrophoretic gels indicated a lack of activity after 30 h in glufosinate and glufosinate plus CT-treated tissue. Untreated control tissues contained much lower ammonia levels at 24, 64, and 88 h after treatment than treatments with CT, glufosinate or their combination. CT alone caused elevated ammonia levels only after 64 - 88 h. Glufosinate incorporated in agar at 0.25 mM to 2.0 mM, caused a 10% - 45% reduction of CT colony radial growth, compared to fungal growth on agar without glufosinate, and the herbicide also inhibited sporulation of CT. Although no synergistic interactions were found in the combinations of CT and glufosinate at the concentrations used, further insight on the biochemical action of CT and its interactions with this herbicide on hemp sesbania was achieved.展开更多
The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequen...The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice （Chunjiang 016 and Xiushui 09）, two inbred indica rice （Zhongzu 14 and Zhongzao 22）, two indica hybrid rice （Zhongzheyou 1 and Guodao 1）, and one weedy indica rice （Taizhou weedy rice）. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows： weedy rice 〉 Chunjiang 016 〉 Xiushui 09 and Zhongzu 14 〉 Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and weedy rice. Averaged across years, the risk of gene flow to weedy rice was higher than that of improved rice and hybrids. Greater resources must be dedicated to the management of remnant weedy rice in fields planted with herbicide-resistant rice, and to prevent the evolution of resistant weedy rice populations.展开更多
Palmer amaranth, sicklepod and pitted morningglory are the three most common and troublesome weeds in soybean in South Carolina. They exhibit very aggressive growth capabilities and if left uncontrolled in fields will...Palmer amaranth, sicklepod and pitted morningglory are the three most common and troublesome weeds in soybean in South Carolina. They exhibit very aggressive growth capabilities and if left uncontrolled in fields will cause significant reductions in soybean yields. Dicamba and 2,4-D herbicides are currently having a resurgence in usage due to the recent commercialization of soybean trait technologies with tolerance to these herbicides. Dicamba and 2,4-D when tank mixed with glufosinate and glyphosate may offer additional weed control to resistant weeds through the process of herbicide synergism. Greenhouse experiments were conducted in 2013 at Edisto Research and Education Center near Blackville, SC to evaluate the efficacy of glyphosate, glufosinate, dicamba and 2,4-D treatments alone and in combination on Palmer amaranth, sicklepod, and pitted morningglory at selected heights. Results suggested that glufosinate alone provided the overall best control for all 3 weed species. Glyphosate alone provided the lowest control of all 3 species at all heights. Synergism or improved sicklepod control was observed when glufosinate was tank mixed with dicamba. However, as sicklepod increased in height, glufosinate + 2,4-D or dicamba combination offered the best control compared to glufosinate alone (90% versus 86% in 20 cm plants and 87% versus 85% in 30 cm plant). In the 5 cm Palmer amaranth, decreased control was observed when glyphosate or glufosinate was tank mixed with 2,4-D. These experiments showed that glufosinate alone and/or in combination with 2,4-D or dicamba was the overall best treatment on the three broadleaf weed species.展开更多
为建立一种离子色谱-质谱法检测血液中γ-羟基丁酸(GHB)、氟乙酸钠、亚硝酸钠、草甘膦和草铵膦五种水溶性毒物的方法,选用AS19阴离子色谱柱进行分离,以在线产生的50 mmol/L氢氧化钠为淋洗液等度淋洗,飞行时间质谱仪作检测器,采用电喷雾...为建立一种离子色谱-质谱法检测血液中γ-羟基丁酸(GHB)、氟乙酸钠、亚硝酸钠、草甘膦和草铵膦五种水溶性毒物的方法,选用AS19阴离子色谱柱进行分离,以在线产生的50 mmol/L氢氧化钠为淋洗液等度淋洗,飞行时间质谱仪作检测器,采用电喷雾电离源负离子模式、选择离子监测模式(Selected Ion Monitor,SIM)进行分析,外标法定量。利用离子色谱-质谱法检测五种水溶性毒物简单快速、专属性强、灵敏度高,可为司法鉴定实践提供重要的科学支撑。展开更多
基金supported by grants from the Shenzhen Science and Technology Program(KQTD20180411143628272)Special Funds for Science Technology Innovation and Industrial Development of Shenzhen Dapeng New District(PT202101-02)+3 种基金the Hainan Yazhou Bay Seed Lab(B21HJ0215),the National Natural Science Foundation of China(32102294)the China National Postdoctoral Program for Innovative Talents(BX2020378)the China Postdoctoral Science Foundation(2020M672902)the Central Publicinterest Scientific Institution Basal Research Fund(Y2022PT24).
文摘Only few glufosinate-tolerant genes,such as phosphinothricin acetyltransferase(PAT)and bialaphos resistance(bar)identified from Streptomyces,are currently available for developing genetically modified rice in agricultural application.Following the rapid development of genome editing technology,generation of novel glufosinate-tolerant gene resources through artificial evolution of endogenous genes is more promising and highly desirable in rice molecular breeding program.In this study,the endogenous Glutamine synthetase1(OsGS1)was artificially evolved by base-editing-mediated gene evolution(BEMGE)in rice cells to create novel alleles conferring glufosinate tolerance in rice germplasms.Two novel glufosinate-tolerant OsGS1 alleles(OsGS1-AVPS and OsGS1-+AF)and one reported tolerant allele(OsGS1-SGTA)were successfully identified from approximately 4200 independent hygromycin-tolerant calli.Germination assays and spray tests revealed that these three OsGS1 alleles confer glufosinate tolerance in rice.Furthermore,OsGS1-AVPS and OsGS1-SGTA were quickly deployed into the elite rice cultivar Nangeng 46 through precise base editing.Overall,our results demonstrate the feasibility of developing glufosinate-tolerant rice by editing an endogenous rice gene in molecular breeding programs.
文摘The use of microbes and microbial products as bioherbicides has been studied for several decades, and combinations of bioherbicides and herbicides have been examined to discover possible synergistic interactions to improve weed control efficacy. Bioassays were conducted to assess possible interactions of the herbicide glufosinate [2-amino-4-(hydroxymethylphosphinyl) butanoic acid] and Colletotrichum truncatum (CT), a fungal bioherbicide to control hemp sesbania (Sesbania exaltata)]. Glufosinate acts as a glutamine synthetase (GS) inhibitor that causes elevated ammonia levels, but the mode of action of CT is unknown. GS has also been implicated in plant defense in certain plant-pathogen interactions. The effects of spray applications of glufosinate (1.0 mM) orbioherbicide (8.0 × 104 conidia ml-1), applied alone or in combination were monitored (88 h time-course) on seedling growth, GS activity and ammonia levels in hypocotyl tissues under controlled environmental conditions. Growth (elongation and fresh weight) and extractable GS activity were inhibited in tissues by glufosinate and glufosinate plus CT treatments as early as 16 h, but CT treatment did not cause substantial growth reduction or GS inhibition until after ~40 h. Generally, ammonia levels in hemp sesbania tissues under these various treatments were inversely correlated with GS activity. Localization of hemp sesbania GS activity on electrophoretic gels indicated a lack of activity after 30 h in glufosinate and glufosinate plus CT-treated tissue. Untreated control tissues contained much lower ammonia levels at 24, 64, and 88 h after treatment than treatments with CT, glufosinate or their combination. CT alone caused elevated ammonia levels only after 64 - 88 h. Glufosinate incorporated in agar at 0.25 mM to 2.0 mM, caused a 10% - 45% reduction of CT colony radial growth, compared to fungal growth on agar without glufosinate, and the herbicide also inhibited sporulation of CT. Although no synergistic interactions were found in the combinations of CT and glufosinate at the concentrations used, further insight on the biochemical action of CT and its interactions with this herbicide on hemp sesbania was achieved.
基金funded by the China Agriculture Research System (Grant No. CARS-01)Zhejiang Science and Technology Project of China (Grant No. 2008C22086)
文摘The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice （Chunjiang 016 and Xiushui 09）, two inbred indica rice （Zhongzu 14 and Zhongzao 22）, two indica hybrid rice （Zhongzheyou 1 and Guodao 1）, and one weedy indica rice （Taizhou weedy rice）. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows： weedy rice 〉 Chunjiang 016 〉 Xiushui 09 and Zhongzu 14 〉 Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and weedy rice. Averaged across years, the risk of gene flow to weedy rice was higher than that of improved rice and hybrids. Greater resources must be dedicated to the management of remnant weedy rice in fields planted with herbicide-resistant rice, and to prevent the evolution of resistant weedy rice populations.
文摘Palmer amaranth, sicklepod and pitted morningglory are the three most common and troublesome weeds in soybean in South Carolina. They exhibit very aggressive growth capabilities and if left uncontrolled in fields will cause significant reductions in soybean yields. Dicamba and 2,4-D herbicides are currently having a resurgence in usage due to the recent commercialization of soybean trait technologies with tolerance to these herbicides. Dicamba and 2,4-D when tank mixed with glufosinate and glyphosate may offer additional weed control to resistant weeds through the process of herbicide synergism. Greenhouse experiments were conducted in 2013 at Edisto Research and Education Center near Blackville, SC to evaluate the efficacy of glyphosate, glufosinate, dicamba and 2,4-D treatments alone and in combination on Palmer amaranth, sicklepod, and pitted morningglory at selected heights. Results suggested that glufosinate alone provided the overall best control for all 3 weed species. Glyphosate alone provided the lowest control of all 3 species at all heights. Synergism or improved sicklepod control was observed when glufosinate was tank mixed with dicamba. However, as sicklepod increased in height, glufosinate + 2,4-D or dicamba combination offered the best control compared to glufosinate alone (90% versus 86% in 20 cm plants and 87% versus 85% in 30 cm plant). In the 5 cm Palmer amaranth, decreased control was observed when glyphosate or glufosinate was tank mixed with 2,4-D. These experiments showed that glufosinate alone and/or in combination with 2,4-D or dicamba was the overall best treatment on the three broadleaf weed species.
文摘为建立一种离子色谱-质谱法检测血液中γ-羟基丁酸(GHB)、氟乙酸钠、亚硝酸钠、草甘膦和草铵膦五种水溶性毒物的方法,选用AS19阴离子色谱柱进行分离,以在线产生的50 mmol/L氢氧化钠为淋洗液等度淋洗,飞行时间质谱仪作检测器,采用电喷雾电离源负离子模式、选择离子监测模式(Selected Ion Monitor,SIM)进行分析,外标法定量。利用离子色谱-质谱法检测五种水溶性毒物简单快速、专属性强、灵敏度高,可为司法鉴定实践提供重要的科学支撑。
