Race-specific resistance and field resistance of 30 rice blast resistance monogenic lines derived from different resources were evaluated. The spectra of resistance to 163 Magnaporthe grisea isolates collected from in...Race-specific resistance and field resistance of 30 rice blast resistance monogenic lines derived from different resources were evaluated. The spectra of resistance to 163 Magnaporthe grisea isolates collected from indica rice in Guangdong Province, China ranged from 0.6% to 89.6%. Most of the monogenic lines showed a narrow resistance spectrum and high susceptibility in rice blast area, whereas the lines with Pikh and Pi1(t) had the broad resistance spectra of 89.6% and 82.2% respectively, showing a high and stable blast resistance in fields. According to the cluster analysis of specific resistance to 163 blast isolates tested, the 30 monogenic lines were divided into 15 groups, and based on the principal factor analysis, nine kinds of race-specific resistance were identified. Pik, Piz5, Pi9 and Pish can be used as candidate resistance genes for rice breeding since their specific resistance differed from those of the backbone parents in Guangdong, China. Gene pyramiding of Pikh [or Pi1(t)], Pi9 (or Piz5) and Pish (or Pita2) will be effective to obtain broad-spectrum blast resistance in rice breeding program in Guangdong, China. The strategies for studying and application of rice blast resistance genes were discussed.展开更多
Six isolates of Magnaporthe grisea were selected to inoculate on 10 Chinese leading maintainer lines (B-lines), 14 restorer lines (R-lines) and their F1 hybrid plants. In the tested rice materials, R-lines were proved...Six isolates of Magnaporthe grisea were selected to inoculate on 10 Chinese leading maintainer lines (B-lines), 14 restorer lines (R-lines) and their F1 hybrid plants. In the tested rice materials, R-lines were proved to be more resistant to blast than B-lines. The resistance frequency of about 25% F1 hybrid plants was less than their parents. In addition, 26 isolates of M. grisea collected from different rice growing areas of China were inoculated on 13 new improved hybrid rice combinations. The resistance frequencies of 5 improved hybrids were better than those of the controls and leading varieties in rice production of China.展开更多
The expression of a protein elicitor from Magnaporthe griesea and its biological function in activating resistance in rice （Oryza safiva L） were reported. The gene of elicitor was expressed in Escherichia colicells ...The expression of a protein elicitor from Magnaporthe griesea and its biological function in activating resistance in rice （Oryza safiva L） were reported. The gene of elicitor was expressed in Escherichia colicells and produced a His6-fusion protein with 42 kD apparent molecular weight on SDS-PAGE. The purified protein could induce the resistance to blast disease, with the control efficiency of 46.47% and 36.41% at the 14^th day and the 21^st day after blast inoculation, respectively. After treatment with the expressed protein, the phenylalanine ammonia-lyase （PAL） and peroxidase （POD） activities were promoted in rice plants, meanwhile, the transcription levels of STKM, FAD, PBZ1 and PR1 genes were increased in rice plants. Moreover, after comparing the profile of total rice leaf proteins on two-dimensional electrophoresis gel, about 14 proteins were found to be increased in expression level after the expressed protein treatment. All the results indicated that the expressed protein could act as an elicitor to trigger the resistance in rice.展开更多
Receptor-like cytoplasmic kinase OsBSK1-2 was reported to play an important role in regulation of response to rice blast,but the signaling pathway remained unknown.In this study,we identified OsMAPKKK18 and previously...Receptor-like cytoplasmic kinase OsBSK1-2 was reported to play an important role in regulation of response to rice blast,but the signaling pathway remained unknown.In this study,we identified OsMAPKKK18 and previously uncharacterized MAPKKKs OsMAPKKK16 and OsMAPKKK19 that interact with OsBSK1-2.Expression of all three MAPKKKs was induced by Magnaporthe oryzae infection,and all three induced cell death when transiently expressed in Nicotiana benthamiana leaves.Knockout of OsMAPKKK16 and OsMAPKKK18 compromised blast resistance and overexpression of OsMAPKKK19 increased blast resistance,indicating that all three MAPKKKs are involved in regulation of rice blast response.Furthermore,both OsMAPKKK16 and OsMAPKKK19 interacted with and phosphorylated OsMKK4 and OsMKK5,and chitin-induced MAPK activation was suppressed in osmapkkk16 and osbsk1-2 mutants.OsMAPKKK18 was earlier reported to interact with and phosphorylate OsMKK4 and affect chitin-induced MAPK activation,suggesting that OsBSK1-2 is involved in regulation of immunity through multiple MAPK signaling pathways.Unlike BSK1 in Arabidopsis,OsBSK1-2 was not involved in response to avirulent M.oryzae strains.Taken together,our results revealed important roles of OsMAPKKK16/18/19 and a OsBSK1-2-OsMAPKKK16/18/19-OsMKK4/5 module in regulating response to rice blast.展开更多
von Willebrand factor A(vWA)genes are well characterized in humans except for few BONZAI genes,but the vWA genes are least explored in plants.Considering the novelty and vital role of vWA genes,this study aimed at cha...von Willebrand factor A(vWA)genes are well characterized in humans except for few BONZAI genes,but the vWA genes are least explored in plants.Considering the novelty and vital role of vWA genes,this study aimed at characterization of vWA superfamily in rice.Rice genome was found to have 40 vWA genes distributed across all the 12 chromosomes,and 20 of the 40 vWA genes were unique while the remaining shared large fragment similarities with each other,indicating gene duplication.In addition to vWA domain,vWA proteins possess other different motifs or domains,such as ubiquitin interacting motif in protein degradation pathway,and RING finger in protein-protein interaction.Expression analysis of vWA genes in available expression data suggested that they probably function in biotic and abiotic stress responses including hormonal response and signaling.The frequency of transposon elements in the entire 3K rice germplasm was negligible except for 9 vWA genes,indicating the importance of these genes in rice.Structural and functional diversities showed that the vWA genes in a blast-resistant rice variety Tetep had huge variations compared to blast-susceptible rice varieties HP2216 and Nipponbare.qRT-PCR analysis of vWA genes in Magnaporthe oryzae infected rice tissues indicated OsvWA9,OsvWA36,OsvWA37 and OsvWA18 as the optimal candidate genes for disease resistance.This is the first attempt to characterize vWA gene family in plant species.展开更多
A genetic cross between Oryza isolate Y93-164a-1 and Eleusine isolate SA98-4 was established, and the pathogenicity of 151 F1 progeny isolates was investigated on both host plants rice and finger millet. Results showe...A genetic cross between Oryza isolate Y93-164a-1 and Eleusine isolate SA98-4 was established, and the pathogenicity of 151 F1 progeny isolates was investigated on both host plants rice and finger millet. Results showed that the segregation of pathogenicity in this genetic cross was abnormal, i.e., most of the progeny isolates were nonpathogenic on both host plants. However, no abnormal segregation was observed when middle repetitive sequence MGR586 and 31 single-copy RFLP markers from all of the chromosomes were genetically analyzed. At the same time, comparison of the chromosomal organization among two pairs of parental isolates did not find any genomic abnormity. These results suggested that the ＂abnormal＂ inheritance of pathogenicity in this cross was most likely due to the reassortment of numerous host species specificity genes but not the biased segregation of the host species specificity genes. The host species specificities in M. grisea were likely to be multigenically controlled, at least in the genetic cross involving rice pathogen and the grasses pathogen other than rice.展开更多
Phenotypical, cytological and molecular responses of rice to the fungus Magnaporthe grisea were studied using rice cultivars and lesion mimic plants. The cultivar Katy was susceptible to several virulent M. grisea iso...Phenotypical, cytological and molecular responses of rice to the fungus Magnaporthe grisea were studied using rice cultivars and lesion mimic plants. The cultivar Katy was susceptible to several virulent M. grisea isolates, and a Sekiguchi like-lesion mimic mutant of Katy （LmmKaty） showed enhanced resistance to these isolates. Lesion mimic phenotype of LmmKaty was rapidly induced by virulent M. grisea isolates or by avirulent ones only at high levels of inoculum. Autofluorescence （a sign of an active defense response） was visible under ultraviolet light 24 h after localized inoculation in the incompatible interaction, whereas, not evident in the compatible interaction. Autofluorescence was also observed in LmmKaty 20 h after pathogen inoculation, indicating that rapid cell death is a mechanism of LmmKaty to restrict pathogen invasion. Rapid accumulations of defense related （DR） gene transcripts, phenylalanine ammonia lyase and β-glucanase, were observed beginning at 6 h and were obvious at 16 h and 24 h after inoculation in an incompatible interaction. Rapid transcript accumulations of PR-1 and chitinase had occurred by 24 h after inoculation in an incompatible interaction. Accumulations of these transcripts were delayed in the compatible interaction. These results indicate that host active defense responses occur 24 h after pathogen inoculation and that LmmKaty exhibits enhanced resistance to M. grisea. It is suggested that the autofluorescence and expression of the DR genes after heavy inoculation are important cytological and molecular markers respectively for early determination of the host response to M. grisea in the rice blast system.展开更多
[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Pr...[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Province where rice blast occurs frequently,60 isolates which were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs,were obtained.Then,20 pathotypes with the six indica host differentials(CO39 NILs) were observed,while 13 pathotypes in four race groups were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of M.grisea populations tested by CO39 NILs was 2.54 and the pathotype 137.1 occurred at predominantly high frequency(21.67%).The diversity of physiological races of M.grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency(73.33%).The diversity of physiological races of M.grisea in Chongyang and Yuan'an were also calculated.Overall,the diversity of pathotypes of M.grisea in Yuan'an was higher than that in Chongyang with the two sets of the host differentials.[Conclusion] This study provided current information on the pathotype spectrum of M.grisea populations in the rice fields of Hubei Province to allow the formulation of viable strategies for blast resistance breeding programs in Hubei Province.展开更多
Fungal strains isolated from the fruiting bodies of wild mushrooms were evaluated for fungicidal activity against Magnaporthe oryzae, the causal agent of the rice blast disease. Fungal isolates (n = 105) were obtained...Fungal strains isolated from the fruiting bodies of wild mushrooms were evaluated for fungicidal activity against Magnaporthe oryzae, the causal agent of the rice blast disease. Fungal isolates (n = 105) were obtained from 46 samples of wild mushrooms. Infection behaviors of M. oryzae were assessed in the presence of culture filtrates from 90 fungal isolates, of which 20 inhibited spore germination. Heat-treated culture filtrates of these isolates were classified into 3 groups according to biological activity. Blast lesion formation by M. oryzae was significantly inhibited by pretreatment with culture filtrates from 4 fungal isolates. ITS region sequence analysis indicated that these?isolates shared similarities with species of the genera Annulohypoxylon, Nigrospora, and Penicillium. Studies of symbiotic and parasitic fungi from wild mushrooms may yield potential control agents for plant diseases such as the rice blast disease.展开更多
基金supported by the ‘948’ Project of Ministry of Agriculture, China (Grant No. 2006-G61)the Natural Science Foundation of Guangdong Province, China (Grant No. 04101156)+2 种基金the Science and Technique Project of Guangdong Province, China (Grant No. 2005B20101006 and No. 0711124900076)the Science and Technique Project of Guangzhou City, China (Grant No. 2005C12E0061)the Science Fundamental Research Foundation of Guangdong Academy of Agricultural Sciences, China.
文摘Race-specific resistance and field resistance of 30 rice blast resistance monogenic lines derived from different resources were evaluated. The spectra of resistance to 163 Magnaporthe grisea isolates collected from indica rice in Guangdong Province, China ranged from 0.6% to 89.6%. Most of the monogenic lines showed a narrow resistance spectrum and high susceptibility in rice blast area, whereas the lines with Pikh and Pi1(t) had the broad resistance spectra of 89.6% and 82.2% respectively, showing a high and stable blast resistance in fields. According to the cluster analysis of specific resistance to 163 blast isolates tested, the 30 monogenic lines were divided into 15 groups, and based on the principal factor analysis, nine kinds of race-specific resistance were identified. Pik, Piz5, Pi9 and Pish can be used as candidate resistance genes for rice breeding since their specific resistance differed from those of the backbone parents in Guangdong, China. Gene pyramiding of Pikh [or Pi1(t)], Pi9 (or Piz5) and Pish (or Pita2) will be effective to obtain broad-spectrum blast resistance in rice breeding program in Guangdong, China. The strategies for studying and application of rice blast resistance genes were discussed.
文摘Six isolates of Magnaporthe grisea were selected to inoculate on 10 Chinese leading maintainer lines (B-lines), 14 restorer lines (R-lines) and their F1 hybrid plants. In the tested rice materials, R-lines were proved to be more resistant to blast than B-lines. The resistance frequency of about 25% F1 hybrid plants was less than their parents. In addition, 26 isolates of M. grisea collected from different rice growing areas of China were inoculated on 13 new improved hybrid rice combinations. The resistance frequencies of 5 improved hybrids were better than those of the controls and leading varieties in rice production of China.
文摘The expression of a protein elicitor from Magnaporthe griesea and its biological function in activating resistance in rice （Oryza safiva L） were reported. The gene of elicitor was expressed in Escherichia colicells and produced a His6-fusion protein with 42 kD apparent molecular weight on SDS-PAGE. The purified protein could induce the resistance to blast disease, with the control efficiency of 46.47% and 36.41% at the 14^th day and the 21^st day after blast inoculation, respectively. After treatment with the expressed protein, the phenylalanine ammonia-lyase （PAL） and peroxidase （POD） activities were promoted in rice plants, meanwhile, the transcription levels of STKM, FAD, PBZ1 and PR1 genes were increased in rice plants. Moreover, after comparing the profile of total rice leaf proteins on two-dimensional electrophoresis gel, about 14 proteins were found to be increased in expression level after the expressed protein treatment. All the results indicated that the expressed protein could act as an elicitor to trigger the resistance in rice.
基金This work was supported by the National Key Research and Development Program of China(2022YFF1001500)Key Program of Technology and Science in Fujian province(2020NZ08016).
文摘Receptor-like cytoplasmic kinase OsBSK1-2 was reported to play an important role in regulation of response to rice blast,but the signaling pathway remained unknown.In this study,we identified OsMAPKKK18 and previously uncharacterized MAPKKKs OsMAPKKK16 and OsMAPKKK19 that interact with OsBSK1-2.Expression of all three MAPKKKs was induced by Magnaporthe oryzae infection,and all three induced cell death when transiently expressed in Nicotiana benthamiana leaves.Knockout of OsMAPKKK16 and OsMAPKKK18 compromised blast resistance and overexpression of OsMAPKKK19 increased blast resistance,indicating that all three MAPKKKs are involved in regulation of rice blast response.Furthermore,both OsMAPKKK16 and OsMAPKKK19 interacted with and phosphorylated OsMKK4 and OsMKK5,and chitin-induced MAPK activation was suppressed in osmapkkk16 and osbsk1-2 mutants.OsMAPKKK18 was earlier reported to interact with and phosphorylate OsMKK4 and affect chitin-induced MAPK activation,suggesting that OsBSK1-2 is involved in regulation of immunity through multiple MAPK signaling pathways.Unlike BSK1 in Arabidopsis,OsBSK1-2 was not involved in response to avirulent M.oryzae strains.Taken together,our results revealed important roles of OsMAPKKK16/18/19 and a OsBSK1-2-OsMAPKKK16/18/19-OsMKK4/5 module in regulating response to rice blast.
基金the Indian Council of Agricultural Research(ICAR)-National Institute for Plant Biotechnology,National Agricultural Higher Education Project:Centre for Advanced Agricultural Science and Technology(Grant No.1010033)ICAR-Centre for Agricultural Bioinformatics,Indian Agricultural Statistics Research Institute,New Delhi(IASRI)(Grant No.1006456).
文摘von Willebrand factor A(vWA)genes are well characterized in humans except for few BONZAI genes,but the vWA genes are least explored in plants.Considering the novelty and vital role of vWA genes,this study aimed at characterization of vWA superfamily in rice.Rice genome was found to have 40 vWA genes distributed across all the 12 chromosomes,and 20 of the 40 vWA genes were unique while the remaining shared large fragment similarities with each other,indicating gene duplication.In addition to vWA domain,vWA proteins possess other different motifs or domains,such as ubiquitin interacting motif in protein degradation pathway,and RING finger in protein-protein interaction.Expression analysis of vWA genes in available expression data suggested that they probably function in biotic and abiotic stress responses including hormonal response and signaling.The frequency of transposon elements in the entire 3K rice germplasm was negligible except for 9 vWA genes,indicating the importance of these genes in rice.Structural and functional diversities showed that the vWA genes in a blast-resistant rice variety Tetep had huge variations compared to blast-susceptible rice varieties HP2216 and Nipponbare.qRT-PCR analysis of vWA genes in Magnaporthe oryzae infected rice tissues indicated OsvWA9,OsvWA36,OsvWA37 and OsvWA18 as the optimal candidate genes for disease resistance.This is the first attempt to characterize vWA gene family in plant species.
基金supported by a project (11660050) from the Ministry of Education, Culture, Sports, ScienceTechnology of Japan and the project of the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Huazhong Agricultural University, China(4002-30541)
文摘A genetic cross between Oryza isolate Y93-164a-1 and Eleusine isolate SA98-4 was established, and the pathogenicity of 151 F1 progeny isolates was investigated on both host plants rice and finger millet. Results showed that the segregation of pathogenicity in this genetic cross was abnormal, i.e., most of the progeny isolates were nonpathogenic on both host plants. However, no abnormal segregation was observed when middle repetitive sequence MGR586 and 31 single-copy RFLP markers from all of the chromosomes were genetically analyzed. At the same time, comparison of the chromosomal organization among two pairs of parental isolates did not find any genomic abnormity. These results suggested that the ＂abnormal＂ inheritance of pathogenicity in this cross was most likely due to the reassortment of numerous host species specificity genes but not the biased segregation of the host species specificity genes. The host species specificities in M. grisea were likely to be multigenically controlled, at least in the genetic cross involving rice pathogen and the grasses pathogen other than rice.
文摘Phenotypical, cytological and molecular responses of rice to the fungus Magnaporthe grisea were studied using rice cultivars and lesion mimic plants. The cultivar Katy was susceptible to several virulent M. grisea isolates, and a Sekiguchi like-lesion mimic mutant of Katy （LmmKaty） showed enhanced resistance to these isolates. Lesion mimic phenotype of LmmKaty was rapidly induced by virulent M. grisea isolates or by avirulent ones only at high levels of inoculum. Autofluorescence （a sign of an active defense response） was visible under ultraviolet light 24 h after localized inoculation in the incompatible interaction, whereas, not evident in the compatible interaction. Autofluorescence was also observed in LmmKaty 20 h after pathogen inoculation, indicating that rapid cell death is a mechanism of LmmKaty to restrict pathogen invasion. Rapid accumulations of defense related （DR） gene transcripts, phenylalanine ammonia lyase and β-glucanase, were observed beginning at 6 h and were obvious at 16 h and 24 h after inoculation in an incompatible interaction. Rapid transcript accumulations of PR-1 and chitinase had occurred by 24 h after inoculation in an incompatible interaction. Accumulations of these transcripts were delayed in the compatible interaction. These results indicate that host active defense responses occur 24 h after pathogen inoculation and that LmmKaty exhibits enhanced resistance to M. grisea. It is suggested that the autofluorescence and expression of the DR genes after heavy inoculation are important cytological and molecular markers respectively for early determination of the host response to M. grisea in the rice blast system.
基金Supported by the Key Project of the National 11th Five-Year Plan of China (2006BADO8A04-06)
文摘[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan'an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan'an in Hubei Province where rice blast occurs frequently,60 isolates which were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs,were obtained.Then,20 pathotypes with the six indica host differentials(CO39 NILs) were observed,while 13 pathotypes in four race groups were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of M.grisea populations tested by CO39 NILs was 2.54 and the pathotype 137.1 occurred at predominantly high frequency(21.67%).The diversity of physiological races of M.grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency(73.33%).The diversity of physiological races of M.grisea in Chongyang and Yuan'an were also calculated.Overall,the diversity of pathotypes of M.grisea in Yuan'an was higher than that in Chongyang with the two sets of the host differentials.[Conclusion] This study provided current information on the pathotype spectrum of M.grisea populations in the rice fields of Hubei Province to allow the formulation of viable strategies for blast resistance breeding programs in Hubei Province.
文摘Fungal strains isolated from the fruiting bodies of wild mushrooms were evaluated for fungicidal activity against Magnaporthe oryzae, the causal agent of the rice blast disease. Fungal isolates (n = 105) were obtained from 46 samples of wild mushrooms. Infection behaviors of M. oryzae were assessed in the presence of culture filtrates from 90 fungal isolates, of which 20 inhibited spore germination. Heat-treated culture filtrates of these isolates were classified into 3 groups according to biological activity. Blast lesion formation by M. oryzae was significantly inhibited by pretreatment with culture filtrates from 4 fungal isolates. ITS region sequence analysis indicated that these?isolates shared similarities with species of the genera Annulohypoxylon, Nigrospora, and Penicillium. Studies of symbiotic and parasitic fungi from wild mushrooms may yield potential control agents for plant diseases such as the rice blast disease.
