As an important rice disease, rice bacterial leaf blight (RBLB, caused by the bacterium Xanthomonas oryzae pv.oryzae), has become widespread in east China in recent years. Significant losses in rice yield occurred as ...As an important rice disease, rice bacterial leaf blight (RBLB, caused by the bacterium Xanthomonas oryzae pv.oryzae), has become widespread in east China in recent years. Significant losses in rice yield occurred as a result ofthe disease’s epidemic, making it imperative to monitor RBLB at a large scale. With the development of remotesensing technology, the broad-band sensors equipped with red-edge channels over multiple spatial resolutionsoffer numerous available data for large-scale monitoring of rice diseases. However, RBLB is characterized by rapiddispersal under suitable conditions, making it difficult to track the disease at a regional scale with a single sensorin practice. Therefore, it is necessary to identify or construct features that are effective across different sensors formonitoring RBLB. To achieve this goal, the spectral response of RBLB was first analyzed based on the canopyhyperspectral data. Using the relative spectral response (RSR) functions of four representative satellite or UAVsensors (i.e., Sentinel-2, GF-6, Planet, and Rededge-M) and the hyperspectral data, the corresponding broad-bandspectral data was simulated. According to a thorough band combination and sensitivity analysis, two novel spectralindices for monitoring RBLB that can be effective across multiple sensors (i.e., RBBRI and RBBDI) weredeveloped. An optimal feature set that includes the two novel indices and a classical vegetation index was formed.The capability of such a feature set in monitoring RBLB was assessed via FLDA and SVM algorithms. The resultdemonstrated that both constructed novel indices exhibited high sensitivity to the disease across multiple sensors.Meanwhile, the feature set yielded an overall accuracy above 90% for all sensors, which indicates its cross-sensorgenerality in monitoring RBLB. The outcome of this research permits disease monitoring with different remotesensing data over a large scale.展开更多
Through recurrent backcrossing in combination with molecular marker-assisted selection (MAS), restorer lines R8006 and Rl176 carrying Xa-21, a gene having broad-spectrum resistance to rice bacterial leaf blight, were ...Through recurrent backcrossing in combination with molecular marker-assisted selection (MAS), restorer lines R8006 and Rl176 carrying Xa-21, a gene having broad-spectrum resistance to rice bacterial leaf blight, were selected. By crossing the two lines to CMS line Zhong 9A, two new hybrid rice combinations, Zhongyou 6 and Zhongyou 1176 were developed. The hybrids showed high resistance to diseases, good grain quality and high yielding potential in national and provincial adaptability and yield trials.展开更多
Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent.IRBB21, wh...Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent.IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC_3F_3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC_3F_3 5.1.5.1, BC_3F_3 5.1.5.12, BC_3F_3 8.5.6.44, BC_3F_3 9.5.4.1 and BC_3F_3 9.5.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.展开更多
An experiment was conducted at Rice Research Institute, Kala Shah Kaku in 2010 during kharif season to study the influence of nitrogen (N) and potash (K) on severity of Bacterial leaf blight (BLB) of rice (Oryza sativ...An experiment was conducted at Rice Research Institute, Kala Shah Kaku in 2010 during kharif season to study the influence of nitrogen (N) and potash (K) on severity of Bacterial leaf blight (BLB) of rice (Oryza sativa L.) aimed at improving productivity. The experiment was laid out in randomized complete block design with factorial arrangement with three replications. Treatments comprised of: 0 kg N ha-1, 75 kg N ha-1, 100 kg N ha-1, 125 kg N ha-1 and 0 kg K ha-1, 50 kg K ha-1, 75 kg K ha-1, 100 kg K ha-1. Data on disease severity and paddy yield were recorded using standard procedures. Paddy yield was affected significantly by various combinations of N & K. In case of bacterial leaf blight, minimum diseased incidence percentage was observed when nitrogen alone was applied @ 75 kg·ha-1 in contrast to fertilizer applied @ 125 kg N ha-1 + 50 kg K ha-1 which showed maximum diseased incidence percentage. Maximum paddy yield (4.32 t·ha-1 ) was recorded when rice was fertilized @ 75 kg N ha-1 + 100 kg K ha-1 as compared to sole fertilization of 75 kg K ha-1 that produced minimum paddy yield (2.40 t·ha-1). Maximum gross income, net returns and benefit cost ratio were obtained where rice crop was fertilized @ 75 kg N ha-1 and 100 kg K ha-1.展开更多
Microorganism isolates (n = 49) were obtained from the soil samples collected from field in Gotsu city (Kawahira), Shimane. Isolate GT2-E culture inhibited the growth of Xanthomonas oryzae pv. oryzae in disk diffusion...Microorganism isolates (n = 49) were obtained from the soil samples collected from field in Gotsu city (Kawahira), Shimane. Isolate GT2-E culture inhibited the growth of Xanthomonas oryzae pv. oryzae in disk diffusion method. Rice bacterial leaf blight was suppressed by GT2-E culture in the pre- and post-treated rice leaves. Sequence analysis of 16S rDNA region of the GT2-E isolate indicated that it shared 99% similarity with Paenibacillus polymyxa. The growth of GT2-E on LB medium was observed at 15°C, 28°C, 37°C, and 45°C, but not at 4°C. GT2-E isolate could be grown even in the presence of agrochemicals (Amister, Blasin and Kasumin). Furthermore, the growth of X. oryzae pv. oryzae was inhibited by the culture filtrate of GT2-E isolate in disk diffusion method. However, the inhibitory activity of the culture filtrate was heat-unstable. This result suggested that GT2-E isolate can produce heat-unstable inhibitory compound(s). In conclusion, GT2-E isolate might contribute to the development of a new bactericide and biological agent against rice bacterial leaf blight.展开更多
Rice is food for more than half of the world population and the most consumable cereal in most of the countries. Pakistan is the fifth largest exporter of rice. However, Bacterial leaf blight (BLB) caused by Xanthomon...Rice is food for more than half of the world population and the most consumable cereal in most of the countries. Pakistan is the fifth largest exporter of rice. However, Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae is the most devastating and serious threat to rice production in many countries of the world including Pakistan. To combat this disease, innate genetic resistance of the plant plays vital role along with being environmentally friendly and economical. In this study, thirty-one (31) Near Isogenic Lines (NILs) having Xa4, xa5, Xa7, xa13 and Xa21 reported BLB tolerant genes and 34 locally developed rice lines were investigated under natural field conditions at three agro-ecologically different locations with highest disease occurrence records (BLB hotspots) viz., Sheikhupura, Hafizabad and Gujranwala, Punjab, Pakistan in order to assess their respective genetic resistance and G × E interactions against the disease. Thirty-one (31) lines were categorized under resistant cluster, twenty-eight (28) were moderately resistant, six (6) were moderately susceptible and one (susceptible check) was in susceptible category. Grouping of different lines/varieties under same cluster shows their significantly similar response against BLB disease in corresponding environment. Among the studied NILs, only one line showed polymorphism for all five resistant genes, two lines had four;seven lines had three genes, seven lines showed di-genic while five lines showed mono-genic polymorphism. These resistant lines with multiple-genes for BLB resistance can be evolved as a new BLB resistant variety and also be utilized as donor parent in breeding programs for developing new cultivars with horizontal resistance against more than one target pathotypes and environments. Xa4 and xa13 were found to deliver significant resistance against the local pathotypes in studied germplasm and NILs.展开更多
The reactions of rice bacterial leaf blight races were identified in Guilan province—Iran on 12 near-isogenic lines and 14 pyramiding lines from International Network for Genetic Evaluation of rice (INGER) and 8 loca...The reactions of rice bacterial leaf blight races were identified in Guilan province—Iran on 12 near-isogenic lines and 14 pyramiding lines from International Network for Genetic Evaluation of rice (INGER) and 8 local and improved Iranian varieties were evaluated under natural photoperiod condition in the field. Inoculation was done at panicle initiation by clipping the sterilized scissors in the bacterial suspension to booting stage. Scoring of inoculated plants was made 21 days after inoculation. Infection levels of pyramiding lines containing two to five resistance genes, expect, IRBB53 and IRBB61 with respectively resistance gene combination, Xa5 + Xa13 and Xa4 + Xa5 + Xa7, were not so clear. Among near-isogenic lines IRBB1, IRBB2, IRBB4 and IRBB10 carrying resistance gene Xa1, Xa2, Xa4 and Xa10 were susceptible;IRBB8, IRBB11, IRBB3, IRBB5 and IRBB13 were moderately susceptible;(having resistance gene Xa8, Xa11, Xa3, Xa5 and Xa13) IRBB14, IRBB21 and IRBB7 with respectively resistance gene Xa14, Xa21 and Xa7 were moderately resistance to bacterial blight. Furthermore, most of the time gene combinations support the strategy of pyramiding appropriate resistance gene. Local varieties were more susceptible than improved varieties to leaf blight disease. Among local varieties, Tarom was the most susceptible. And also, there were no significant differences among improved varieties and all of them were moderately resistance.展开更多
A spotted-leaf mutant of rice HM143 was isolated from an EMS-induced IR64 mutant bank. Brown lesions randomly distributed on leaf blades were observed about 3 wk after sowing. The symptom lasted for the whole plant gr...A spotted-leaf mutant of rice HM143 was isolated from an EMS-induced IR64 mutant bank. Brown lesions randomly distributed on leaf blades were observed about 3 wk after sowing. The symptom lasted for the whole plant growth duration. Histochemical analysis indicated that cell death occurred in and around the site of necrotic lesions accompanied with accumulation of hydrogen hyperoxide. Agronomic traits were largely similar to the wild type IR64 except seed setting rate and 1 000-grain weight which were significantly decreased in the mutant. Disease resistance of the mutant to multiple races of Xanthomonas oryzae pv. oryzae was significantly enhanced. Genetic analysis showed that the mutation was controlled by a single recessive gene, tentatively termed splHM143. In addition, using molecular markers and 1023 mutant type individuals from an F2 segregating population derived from the cross HM143/R9308, the spotted-leaf gene was finally delimited to an interval of 149 kb between markers XX25 and ID40 on the long arm of chromosome 4. splHM143 is likely a novel rice spotted-leaf gene since no other similar genes have been identified near the chromosomal region.展开更多
In this study, the characteristic of three transformants named as B1C106-1, B1C106-2, and B1C106-3 were studied that carried three innate resistant genes Bph14, Bph15, and Xa23, and two enthetic resistant genes CrylCa...In this study, the characteristic of three transformants named as B1C106-1, B1C106-2, and B1C106-3 were studied that carried three innate resistant genes Bph14, Bph15, and Xa23, and two enthetic resistant genes CrylCa# and Bar. The five resistant genes were all verified by PCR and the two enthetic genes were identified in single copy insertion by Southern blot. At tillering stage, the CrylC and PAT （phosphinothricin acetyl transferase） protein contents in leaf, sheath, and stem of T2 generation were in the similar pattern： leaf〉stem〉sheath, and showed significant difference （P〈0.01） among three organs. The average contents of CrylC protein in plant of B1C106-1, B1C106-2, and BIC106-3 were 12.95, 6.57, and 11.30 μg g-1, respectively, and showed significant difference （P〈0.01） among them. However, the average contents of PAT in plant of B1C106-1, B1C106-2, and B1C106-3 were 28.54, 27.66, and 28.02 pg g-1, respectively, and there were no significant difference among three transformants. The glufosinate tolerable concentration of three transformants of T3 generation reached at least 6 g L-1, and the mortality of rice leaf rollers were above 97.4% in 5 days after being fed with fresh transformants＇ leaves. The CrylC protein toxicity was also assessed by silkworms, and the mortality of silkworms feeding mulberry leaves smeared with Cry1C protein extracts of leaves of B1 C106-1, BIC106-2, and B1 C106-3 were 90, 67.8, and 87.8%, respectively, that were positive correlation （r=0.993） with CrylC protein contents in plant of three transformants. The three transformants also maintained high resistance to brown planthopper and bacterial blight as the original version. The above results indicate the tetra-resistant rice germplasm was well-developed by pyramiding innate and enthetic resistant genes in an elite line to provide with resistances of glufosinate, rice leaf roller, brown planthopper, and bacterial blight.展开更多
Xanthomonas spp. cause severe bacterial diseases. However, effective strategies for prevention and management of these diseases are scarce. Thus, it is necessary to improve the efficiency of control of diseases caused...Xanthomonas spp. cause severe bacterial diseases. However, effective strategies for prevention and management of these diseases are scarce. Thus, it is necessary to improve the efficiency of control of diseases caused by Xanthomonas. In this study, Xanthomonas oryzae pv. oryzae(Xoo), which causes rice bacterial leaf blight, has been studied as a representative. A transposon insertion library of Xoo, comprising approximately 200,000 individual insertion mutants, was generated. Transposon sequencing data indicated that the mariner C9 transposase mapped at 35.7–36.4% of all potential insertion sites, revealing 491 essential genes required for the growth of Xoo in rich media. The results show that, compared to the functions of essential genes of other bacteria, the functions of some essential genes of Xoo are unknown, 25 genes might be dangerous for the Xanthomonas group, and 3 are specific to Xanthomonas. High-priority candidates for developing broad-spectrum, Xanthomonas-specific, and environment-friendly bactericides were identified in this study. In addition, this study revealed the possible targets of dioctyldiethylenetriamine using surface plasmon resonance(SPR) in combination with high performance liquid chromatography–mass spectrometry(HPLC–MS). The study also provided references for the research of some certain bactericides with unknown anti-bacterial mode of action. In conclusion, this study urged a better understanding of Xanthomonas,provided meaningful data for the management of bacterial leaf blight, and disclosed selected targets of a novel bactericide.展开更多
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA28010500)National Natural Science Foundation of China(Grant Nos.42371385,42071420)Zhejiang Provincial Natural Science Foundation of China(Grant No.LTGN23D010002).
文摘As an important rice disease, rice bacterial leaf blight (RBLB, caused by the bacterium Xanthomonas oryzae pv.oryzae), has become widespread in east China in recent years. Significant losses in rice yield occurred as a result ofthe disease’s epidemic, making it imperative to monitor RBLB at a large scale. With the development of remotesensing technology, the broad-band sensors equipped with red-edge channels over multiple spatial resolutionsoffer numerous available data for large-scale monitoring of rice diseases. However, RBLB is characterized by rapiddispersal under suitable conditions, making it difficult to track the disease at a regional scale with a single sensorin practice. Therefore, it is necessary to identify or construct features that are effective across different sensors formonitoring RBLB. To achieve this goal, the spectral response of RBLB was first analyzed based on the canopyhyperspectral data. Using the relative spectral response (RSR) functions of four representative satellite or UAVsensors (i.e., Sentinel-2, GF-6, Planet, and Rededge-M) and the hyperspectral data, the corresponding broad-bandspectral data was simulated. According to a thorough band combination and sensitivity analysis, two novel spectralindices for monitoring RBLB that can be effective across multiple sensors (i.e., RBBRI and RBBDI) weredeveloped. An optimal feature set that includes the two novel indices and a classical vegetation index was formed.The capability of such a feature set in monitoring RBLB was assessed via FLDA and SVM algorithms. The resultdemonstrated that both constructed novel indices exhibited high sensitivity to the disease across multiple sensors.Meanwhile, the feature set yielded an overall accuracy above 90% for all sensors, which indicates its cross-sensorgenerality in monitoring RBLB. The outcome of this research permits disease monitoring with different remotesensing data over a large scale.
文摘Through recurrent backcrossing in combination with molecular marker-assisted selection (MAS), restorer lines R8006 and Rl176 carrying Xa-21, a gene having broad-spectrum resistance to rice bacterial leaf blight, were selected. By crossing the two lines to CMS line Zhong 9A, two new hybrid rice combinations, Zhongyou 6 and Zhongyou 1176 were developed. The hybrids showed high resistance to diseases, good grain quality and high yielding potential in national and provincial adaptability and yield trials.
文摘Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent.IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC_3F_3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC_3F_3 5.1.5.1, BC_3F_3 5.1.5.12, BC_3F_3 8.5.6.44, BC_3F_3 9.5.4.1 and BC_3F_3 9.5.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.
文摘An experiment was conducted at Rice Research Institute, Kala Shah Kaku in 2010 during kharif season to study the influence of nitrogen (N) and potash (K) on severity of Bacterial leaf blight (BLB) of rice (Oryza sativa L.) aimed at improving productivity. The experiment was laid out in randomized complete block design with factorial arrangement with three replications. Treatments comprised of: 0 kg N ha-1, 75 kg N ha-1, 100 kg N ha-1, 125 kg N ha-1 and 0 kg K ha-1, 50 kg K ha-1, 75 kg K ha-1, 100 kg K ha-1. Data on disease severity and paddy yield were recorded using standard procedures. Paddy yield was affected significantly by various combinations of N & K. In case of bacterial leaf blight, minimum diseased incidence percentage was observed when nitrogen alone was applied @ 75 kg·ha-1 in contrast to fertilizer applied @ 125 kg N ha-1 + 50 kg K ha-1 which showed maximum diseased incidence percentage. Maximum paddy yield (4.32 t·ha-1 ) was recorded when rice was fertilized @ 75 kg N ha-1 + 100 kg K ha-1 as compared to sole fertilization of 75 kg K ha-1 that produced minimum paddy yield (2.40 t·ha-1). Maximum gross income, net returns and benefit cost ratio were obtained where rice crop was fertilized @ 75 kg N ha-1 and 100 kg K ha-1.
文摘Microorganism isolates (n = 49) were obtained from the soil samples collected from field in Gotsu city (Kawahira), Shimane. Isolate GT2-E culture inhibited the growth of Xanthomonas oryzae pv. oryzae in disk diffusion method. Rice bacterial leaf blight was suppressed by GT2-E culture in the pre- and post-treated rice leaves. Sequence analysis of 16S rDNA region of the GT2-E isolate indicated that it shared 99% similarity with Paenibacillus polymyxa. The growth of GT2-E on LB medium was observed at 15°C, 28°C, 37°C, and 45°C, but not at 4°C. GT2-E isolate could be grown even in the presence of agrochemicals (Amister, Blasin and Kasumin). Furthermore, the growth of X. oryzae pv. oryzae was inhibited by the culture filtrate of GT2-E isolate in disk diffusion method. However, the inhibitory activity of the culture filtrate was heat-unstable. This result suggested that GT2-E isolate can produce heat-unstable inhibitory compound(s). In conclusion, GT2-E isolate might contribute to the development of a new bactericide and biological agent against rice bacterial leaf blight.
文摘Rice is food for more than half of the world population and the most consumable cereal in most of the countries. Pakistan is the fifth largest exporter of rice. However, Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae is the most devastating and serious threat to rice production in many countries of the world including Pakistan. To combat this disease, innate genetic resistance of the plant plays vital role along with being environmentally friendly and economical. In this study, thirty-one (31) Near Isogenic Lines (NILs) having Xa4, xa5, Xa7, xa13 and Xa21 reported BLB tolerant genes and 34 locally developed rice lines were investigated under natural field conditions at three agro-ecologically different locations with highest disease occurrence records (BLB hotspots) viz., Sheikhupura, Hafizabad and Gujranwala, Punjab, Pakistan in order to assess their respective genetic resistance and G × E interactions against the disease. Thirty-one (31) lines were categorized under resistant cluster, twenty-eight (28) were moderately resistant, six (6) were moderately susceptible and one (susceptible check) was in susceptible category. Grouping of different lines/varieties under same cluster shows their significantly similar response against BLB disease in corresponding environment. Among the studied NILs, only one line showed polymorphism for all five resistant genes, two lines had four;seven lines had three genes, seven lines showed di-genic while five lines showed mono-genic polymorphism. These resistant lines with multiple-genes for BLB resistance can be evolved as a new BLB resistant variety and also be utilized as donor parent in breeding programs for developing new cultivars with horizontal resistance against more than one target pathotypes and environments. Xa4 and xa13 were found to deliver significant resistance against the local pathotypes in studied germplasm and NILs.
文摘The reactions of rice bacterial leaf blight races were identified in Guilan province—Iran on 12 near-isogenic lines and 14 pyramiding lines from International Network for Genetic Evaluation of rice (INGER) and 8 local and improved Iranian varieties were evaluated under natural photoperiod condition in the field. Inoculation was done at panicle initiation by clipping the sterilized scissors in the bacterial suspension to booting stage. Scoring of inoculated plants was made 21 days after inoculation. Infection levels of pyramiding lines containing two to five resistance genes, expect, IRBB53 and IRBB61 with respectively resistance gene combination, Xa5 + Xa13 and Xa4 + Xa5 + Xa7, were not so clear. Among near-isogenic lines IRBB1, IRBB2, IRBB4 and IRBB10 carrying resistance gene Xa1, Xa2, Xa4 and Xa10 were susceptible;IRBB8, IRBB11, IRBB3, IRBB5 and IRBB13 were moderately susceptible;(having resistance gene Xa8, Xa11, Xa3, Xa5 and Xa13) IRBB14, IRBB21 and IRBB7 with respectively resistance gene Xa14, Xa21 and Xa7 were moderately resistance to bacterial blight. Furthermore, most of the time gene combinations support the strategy of pyramiding appropriate resistance gene. Local varieties were more susceptible than improved varieties to leaf blight disease. Among local varieties, Tarom was the most susceptible. And also, there were no significant differences among improved varieties and all of them were moderately resistance.
基金the Sate Key Laboratory of Rice Biology,China(ZZKT200801)the National High-Tech R&D Program of China(2011AA10A101 and 2012AA101102)
文摘A spotted-leaf mutant of rice HM143 was isolated from an EMS-induced IR64 mutant bank. Brown lesions randomly distributed on leaf blades were observed about 3 wk after sowing. The symptom lasted for the whole plant growth duration. Histochemical analysis indicated that cell death occurred in and around the site of necrotic lesions accompanied with accumulation of hydrogen hyperoxide. Agronomic traits were largely similar to the wild type IR64 except seed setting rate and 1 000-grain weight which were significantly decreased in the mutant. Disease resistance of the mutant to multiple races of Xanthomonas oryzae pv. oryzae was significantly enhanced. Genetic analysis showed that the mutation was controlled by a single recessive gene, tentatively termed splHM143. In addition, using molecular markers and 1023 mutant type individuals from an F2 segregating population derived from the cross HM143/R9308, the spotted-leaf gene was finally delimited to an interval of 149 kb between markers XX25 and ID40 on the long arm of chromosome 4. splHM143 is likely a novel rice spotted-leaf gene since no other similar genes have been identified near the chromosomal region.
基金supported by the State Key Science and Technology Programme on Breeding of New Genetically Modified Organisms, China (2011ZX08001-003 and 2016ZX08001-003)the Open Research Fund of State Key Laboratory of Hybrid Rice (Hunan Hybrid Rice Research Center), China
文摘In this study, the characteristic of three transformants named as B1C106-1, B1C106-2, and B1C106-3 were studied that carried three innate resistant genes Bph14, Bph15, and Xa23, and two enthetic resistant genes CrylCa# and Bar. The five resistant genes were all verified by PCR and the two enthetic genes were identified in single copy insertion by Southern blot. At tillering stage, the CrylC and PAT （phosphinothricin acetyl transferase） protein contents in leaf, sheath, and stem of T2 generation were in the similar pattern： leaf〉stem〉sheath, and showed significant difference （P〈0.01） among three organs. The average contents of CrylC protein in plant of B1C106-1, B1C106-2, and BIC106-3 were 12.95, 6.57, and 11.30 μg g-1, respectively, and showed significant difference （P〈0.01） among them. However, the average contents of PAT in plant of B1C106-1, B1C106-2, and B1C106-3 were 28.54, 27.66, and 28.02 pg g-1, respectively, and there were no significant difference among three transformants. The glufosinate tolerable concentration of three transformants of T3 generation reached at least 6 g L-1, and the mortality of rice leaf rollers were above 97.4% in 5 days after being fed with fresh transformants＇ leaves. The CrylC protein toxicity was also assessed by silkworms, and the mortality of silkworms feeding mulberry leaves smeared with Cry1C protein extracts of leaves of B1 C106-1, BIC106-2, and B1 C106-3 were 90, 67.8, and 87.8%, respectively, that were positive correlation （r=0.993） with CrylC protein contents in plant of three transformants. The three transformants also maintained high resistance to brown planthopper and bacterial blight as the original version. The above results indicate the tetra-resistant rice germplasm was well-developed by pyramiding innate and enthetic resistant genes in an elite line to provide with resistances of glufosinate, rice leaf roller, brown planthopper, and bacterial blight.
基金This study was supported by the National Natural Science Foundation of China(32272587 and 32202342)the Programs for the Scientific Research Activities of Academic and Technical Leaders of Anhui Province,China(2020D251)+3 种基金the Development Fund for Talent Personnel of Anhui Agricultural University,China(rc342006)the University Synergy Innovation Program of Anhui Province,China(GXXT-2021-059)the Key Project of the Natural Science Foundation of Anhui Provincial Department of Education,China(2023AH040129)Anhui Province Agricultural Eco-Environmental Protection and Quality Safety Industry Technology System,China。
文摘Xanthomonas spp. cause severe bacterial diseases. However, effective strategies for prevention and management of these diseases are scarce. Thus, it is necessary to improve the efficiency of control of diseases caused by Xanthomonas. In this study, Xanthomonas oryzae pv. oryzae(Xoo), which causes rice bacterial leaf blight, has been studied as a representative. A transposon insertion library of Xoo, comprising approximately 200,000 individual insertion mutants, was generated. Transposon sequencing data indicated that the mariner C9 transposase mapped at 35.7–36.4% of all potential insertion sites, revealing 491 essential genes required for the growth of Xoo in rich media. The results show that, compared to the functions of essential genes of other bacteria, the functions of some essential genes of Xoo are unknown, 25 genes might be dangerous for the Xanthomonas group, and 3 are specific to Xanthomonas. High-priority candidates for developing broad-spectrum, Xanthomonas-specific, and environment-friendly bactericides were identified in this study. In addition, this study revealed the possible targets of dioctyldiethylenetriamine using surface plasmon resonance(SPR) in combination with high performance liquid chromatography–mass spectrometry(HPLC–MS). The study also provided references for the research of some certain bactericides with unknown anti-bacterial mode of action. In conclusion, this study urged a better understanding of Xanthomonas,provided meaningful data for the management of bacterial leaf blight, and disclosed selected targets of a novel bactericide.
