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
The rice pattern recognition receptor （PRR） XA21 confers race-specific resistance in leaf infection by bacterial blight Xathornonas oryzae pv. oryzae （Xoo）, and was shown to be primarily localized to the endoplasm...The rice pattern recognition receptor （PRR） XA21 confers race-specific resistance in leaf infection by bacterial blight Xathornonas oryzae pv. oryzae （Xoo）, and was shown to be primarily localized to the endoplasmic reticulum （ER） when expressed with its native promoter or overexpressed in the protoplast. However, whether the protein is still ER- localization in the intact cell when overexpressed remains to be identified. Here, we showed that XA21, its kinase-dead mutant XA21PK736EP and the triple autophosphorylation mutant XA21PS686AJT688AJS699A GFP fusions were primarily localized to the plasma membrane （PM） when overexpressed in the intact transgenic rice cell, and also localized to the ER in the transgenic protoplast. The transgenic plants constitutively expressing the wild-type XA21 or its GFP fusion displayed racespecific resistance to Xoo at the adult and seedling stages. XA21 and XA21PK736EP could be internalized probably via the SCAMP-positive early endosomal compartment in the protoplast, suggesting that XA21 might be endocytosed to initiate resistance responses during pathogen infection. We also established a root infection system and demonstrated that XA21 also mediated race-specific resistance responses to Xoo in the root. Our current study provides an insight into the nature of the XA21-mediated resistance and a practical approach using the root cell system to further dissect the cellular signaling of the PRR during the rice-Xoo interaction.展开更多
Races belonging to the Ug99(TTKSK) lineage of the wheat stem rust fungus, carrying complex virulence combinations, and their migration to countries in Africa,Middle East and Asia continue to pose a significant threat ...Races belonging to the Ug99(TTKSK) lineage of the wheat stem rust fungus, carrying complex virulence combinations, and their migration to countries in Africa,Middle East and Asia continue to pose a significant threat to global wheat production.The rapid spread of additional races, e.g., TKTTF or the Digalu lineage, in several countries causing localized epidemics reminds us of the vulnerability of wheat germplasm to stem rust disease, a formidable foe referenced as early as biblical times.A global rust monitoring system reflecting increased surveillance efforts has identified 13 races within the Ug99 lineage in 13 countries and unrelated lineages are emerging, spreading and posing serious threats to wheat production.Race TKTTF has caused localized epidemics in Ethiopia and its variants have been recently implicated in stem rust outbreaks in Europe.Concerted research efforts have resulted in the identification of several new resistance genes and gene combinations for use in breeding.Combining multiple adult plant resistance(APR) genes in high-yielding backgrounds and discovery of new quantitative trait loci conferring stem rust resistance has progressed in the recent years, enhancing the durability of resistance.Effective gene stewardship and new generation breeding materials and cultivars that combine multiple race-specific or minor to intermediate effect APR genes,complemented by active surveillance and monitoring, have helped to limit major epidemics and increase grain yield potential in key target environments.展开更多
HLA-Dw specificities defined by homozygous typing cells reflect a composite effect of allogeneic epitopes of surface antigens encoded by HLA class Ⅱ genes. Different HLA aUelic variants and combinations between races...HLA-Dw specificities defined by homozygous typing cells reflect a composite effect of allogeneic epitopes of surface antigens encoded by HLA class Ⅱ genes. Different HLA aUelic variants and combinations between races and ethnic groups, therefore, can be revealed sensitively by Dw polymorphism and/or Dw haplotypes (see Ref. [3] ). We reported previously the Dw frequencies and Dw-DR-DQ relationship in Chinese population, and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The rice pattern recognition receptor （PRR） XA21 confers race-specific resistance in leaf infection by bacterial blight Xathornonas oryzae pv. oryzae （Xoo）, and was shown to be primarily localized to the endoplasmic reticulum （ER） when expressed with its native promoter or overexpressed in the protoplast. However, whether the protein is still ER- localization in the intact cell when overexpressed remains to be identified. Here, we showed that XA21, its kinase-dead mutant XA21PK736EP and the triple autophosphorylation mutant XA21PS686AJT688AJS699A GFP fusions were primarily localized to the plasma membrane （PM） when overexpressed in the intact transgenic rice cell, and also localized to the ER in the transgenic protoplast. The transgenic plants constitutively expressing the wild-type XA21 or its GFP fusion displayed racespecific resistance to Xoo at the adult and seedling stages. XA21 and XA21PK736EP could be internalized probably via the SCAMP-positive early endosomal compartment in the protoplast, suggesting that XA21 might be endocytosed to initiate resistance responses during pathogen infection. We also established a root infection system and demonstrated that XA21 also mediated race-specific resistance responses to Xoo in the root. Our current study provides an insight into the nature of the XA21-mediated resistance and a practical approach using the root cell system to further dissect the cellular signaling of the PRR during the rice-Xoo interaction.
基金financial support particularly from the DGGW Project managed by Cornell University and funded by the Bill and Melinda Gates Foundation and the UK Department for International Development, as well as the Indian Council of Agricultural Research, USAID, USDA-ARS and GRDC-Australia
文摘Races belonging to the Ug99(TTKSK) lineage of the wheat stem rust fungus, carrying complex virulence combinations, and their migration to countries in Africa,Middle East and Asia continue to pose a significant threat to global wheat production.The rapid spread of additional races, e.g., TKTTF or the Digalu lineage, in several countries causing localized epidemics reminds us of the vulnerability of wheat germplasm to stem rust disease, a formidable foe referenced as early as biblical times.A global rust monitoring system reflecting increased surveillance efforts has identified 13 races within the Ug99 lineage in 13 countries and unrelated lineages are emerging, spreading and posing serious threats to wheat production.Race TKTTF has caused localized epidemics in Ethiopia and its variants have been recently implicated in stem rust outbreaks in Europe.Concerted research efforts have resulted in the identification of several new resistance genes and gene combinations for use in breeding.Combining multiple adult plant resistance(APR) genes in high-yielding backgrounds and discovery of new quantitative trait loci conferring stem rust resistance has progressed in the recent years, enhancing the durability of resistance.Effective gene stewardship and new generation breeding materials and cultivars that combine multiple race-specific or minor to intermediate effect APR genes,complemented by active surveillance and monitoring, have helped to limit major epidemics and increase grain yield potential in key target environments.
基金This study was supported by the grants from the Ministry of Health and the National Natural Science Foundation of China.
文摘HLA-Dw specificities defined by homozygous typing cells reflect a composite effect of allogeneic epitopes of surface antigens encoded by HLA class Ⅱ genes. Different HLA aUelic variants and combinations between races and ethnic groups, therefore, can be revealed sensitively by Dw polymorphism and/or Dw haplotypes (see Ref. [3] ). We reported previously the Dw frequencies and Dw-DR-DQ relationship in Chinese population, and
