A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified. The mutant expressed hypersensitive response （HR）-like symptoms throughout its whole life from the first ...A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified. The mutant expressed hypersensitive response （HR）-like symptoms throughout its whole life from the first leaf to the flag leaf, without pathogen invasion. Initiation of the lesions was induced by light under natural summer field conditions. Expression of pathogenesis-related genes including PAL, PO-C1, POX22.3 and PBZ1 was enhanced significantly in association with cell death and accumulation of H2O2 at and around the site of lesions in the mutant in contrast to that in the wild-type （WT）. Disease reaction to Xanthomonas oryzae pv. oryzae from the Philippines and China showed that HM47 is a broad-spectrum disease-resistant mutant with enhanced resistance to multiple races of bacterial blight pathogens tested. An F2 progeny test showed that bacterial blight resistance to race HB-17 was cosegregated with the expression of lesions. Genetic analysis indicated that the spotted-leaf trait was controlled by a single recessive gene, tentatively named spl HM47 , flanked by two insertion/deletion markers in a region of approximately 74 kb on the long arm of chromosome 4. Ten open reading frames are predicted, and all of them are expressed proteins. Isolation and validation of the putative genes are currently underway.展开更多
Modular proteins are an evolutionary answer to optimize performance of proteins that physically interact with each other for functionality. Using a combination of genetic and biochemical experiments, we charac-terized...Modular proteins are an evolutionary answer to optimize performance of proteins that physically interact with each other for functionality. Using a combination of genetic and biochemical experiments, we charac-terized the rice protein OsJAC1, which consists of a jacalin-related lectin （JRL） domain predicted to bind mannose-containing oligosaccharides, and a dirigent domain which might function in stereoselective coupling of monolignols. Transgenic overexpression of OsJAC1 in rice resulted in quantitative broad- spectrum resistance against different pathogens including bacteria, oomycetes, and fungi. Overexpression of this gene or its wheat ortholog TAJA1 in barley enhanced resistance against the powdery mildew fungus. Both protein domains of OsJAC1 are required to establish resistance as indicated by single or combined transient expression of individual domains. Expression of artificially separated and fluorescence-tagged protein domains showed that the JRL domain is sufficient for targeting the powdery mildew penetration site. Nevertheless, co-localization of the lectin and the dirigent domain occurred. Phylogenetic analyses re- vealed orthologs of OsJAC1 exclusively within the Poaceae plant family. Dicots, by contrast, only contain proteins with either JRL or dirigent domain（s）. Altogether, our results identify OsJAC1 as a representative of a novel type of resistance protein derived from a plant lineage-specific gene fusion event for better function in local pathogen defense.展开更多
Engineering disease-resistant plants can be a powerful solution to the issue of food security.However,it requires addressing two fundamental questions:what genes to express and how to control their expressions.To find...Engineering disease-resistant plants can be a powerful solution to the issue of food security.However,it requires addressing two fundamental questions:what genes to express and how to control their expressions.To find a solution,we screen CRISPR-edited upstream open reading frame(uORF)variants in rice,aiming to optimize translational control of disease-related genes.By switching uORF types of the 5′-leader from Arabidopsis TBF1,we modulate the ribosome accessibility to the downstream firefly luciferase.We assume that by switching uORF types using CRISPR,we could generate uORF variants with alternative translation efficiency(CRISPR-aTrE-uORF).These variants,capable of boosting translation for resistance-associated genes and dampening it for susceptible ones,can help pinpoint previously unidentified genes with optimal expression levels.To test the assumption,we screened edited uORF variants and found that enhanced translational suppression of the plastic glutamine synthetase 2 can provide broad-spectrum disease resistance in rice with minimal fitness costs.This strategy,which involves modifying uORFs from none to some,or from some to none or different ones,demonstrates how translational agriculture can speed up the development of disease-resistant crops.This is vital for tackling the food security challenges we face due to growing populations and changing climates.展开更多
Diverse bacterial and fungal pathogens attack plants,causing biotic stress and severe yield losses globally.These losses are expected to become more serious as climate change improves conditions for many pathogens.The...Diverse bacterial and fungal pathogens attack plants,causing biotic stress and severe yield losses globally.These losses are expected to become more serious as climate change improves conditions for many pathogens.Therefore,identifying genes conferring broad-spectrum disease resistance and elucidating their underlying mechanisms provides important resources for plant breeding.WRKY transcription factors affect plant growth and stress responses.However,the functions of many WRKY proteins remain to be elucidated.Here,we demonstrated the role of rice(Oryza sativa)WRKY groupⅢtranscription factor OsWRKY65 in immunity.OsWRKY65 localized to the nucleus and acted as transcriptional repressor.Genetic and molecular functional analyses showed that OsWRKY65 increases resistance to the fungal pathogen Fusarium fujikuroi through downregulation of GA signaling and upregulation of JA signaling.Moreover,OsWRKY65 modulated the expression of the key genes that confer susceptibility or resistance to Xanthomonas oryzae pv.oryzae to enhance immunity against the pathogen.In particular,OsWRKY65directly bound to the promoter region of OsSWEET13 and repressed its expression.Taken together,our findings demonstrate that the OsWRKY65 enhances resistance to fungal and bacterial pathogens in rice.展开更多
NPR1 is an intersection of different disease resistance pathways and plays a key role in systemic-acquired resistance and induced systemic resistance. NPR1 regulates constitutive resistance and disease resistance dete...NPR1 is an intersection of different disease resistance pathways and plays a key role in systemic-acquired resistance and induced systemic resistance. NPR1 regulates constitutive resistance and disease resistance determined by resistant genes. In this paper, the mechanism of disease resistance of NPR1 genes and its analogs were described. The research status and progress of NPR1 transgenic crops were systematically discussed. The application prospect of NPR1 transgenic crops was also forecasted.展开更多
Systemic acquired resistance (SAR), known as the broad-spectrum, inducible plant immunity, is a defense response triggered by pathogen infection. The response starts from the recognition of plant resistance (R) with t...Systemic acquired resistance (SAR), known as the broad-spectrum, inducible plant immunity, is a defense response triggered by pathogen infection. The response starts from the recognition of plant resistance (R) with the corresponding avirulence (avr) gene from the pathogen. There are some genes for convergence of signals downstream of different R/avr interacting partners into a single signaling pathway. Salicylic acid (SA) is required for the induction of SAR and involved in transducing the signal in target tissues. The SA signal is transduced through NPR1, a nuclear-localized protein that interacts with transcription factors that are involved in regulating SA-mediated gene expression. Some chemicals that mimic natural signaling compounds can also activate SAR. The application of biochemical activators to agriculture for plant protection is a novel idea for developing green chemical pesticide.展开更多
基金supported by the National Hi-Tech Research and Development Program of China(2011AA10A101 and 2012AA101102)the State Key Laboratory of Rice Biology(ZZKT200801)
文摘A stable inherited rice spotted-leaf mutant HM47 derived from an EMS-induced IR64 mutant bank was identified. The mutant expressed hypersensitive response （HR）-like symptoms throughout its whole life from the first leaf to the flag leaf, without pathogen invasion. Initiation of the lesions was induced by light under natural summer field conditions. Expression of pathogenesis-related genes including PAL, PO-C1, POX22.3 and PBZ1 was enhanced significantly in association with cell death and accumulation of H2O2 at and around the site of lesions in the mutant in contrast to that in the wild-type （WT）. Disease reaction to Xanthomonas oryzae pv. oryzae from the Philippines and China showed that HM47 is a broad-spectrum disease-resistant mutant with enhanced resistance to multiple races of bacterial blight pathogens tested. An F2 progeny test showed that bacterial blight resistance to race HB-17 was cosegregated with the expression of lesions. Genetic analysis indicated that the spotted-leaf trait was controlled by a single recessive gene, tentatively named spl HM47 , flanked by two insertion/deletion markers in a region of approximately 74 kb on the long arm of chromosome 4. Ten open reading frames are predicted, and all of them are expressed proteins. Isolation and validation of the putative genes are currently underway.
文摘Modular proteins are an evolutionary answer to optimize performance of proteins that physically interact with each other for functionality. Using a combination of genetic and biochemical experiments, we charac-terized the rice protein OsJAC1, which consists of a jacalin-related lectin （JRL） domain predicted to bind mannose-containing oligosaccharides, and a dirigent domain which might function in stereoselective coupling of monolignols. Transgenic overexpression of OsJAC1 in rice resulted in quantitative broad- spectrum resistance against different pathogens including bacteria, oomycetes, and fungi. Overexpression of this gene or its wheat ortholog TAJA1 in barley enhanced resistance against the powdery mildew fungus. Both protein domains of OsJAC1 are required to establish resistance as indicated by single or combined transient expression of individual domains. Expression of artificially separated and fluorescence-tagged protein domains showed that the JRL domain is sufficient for targeting the powdery mildew penetration site. Nevertheless, co-localization of the lectin and the dirigent domain occurred. Phylogenetic analyses re- vealed orthologs of OsJAC1 exclusively within the Poaceae plant family. Dicots, by contrast, only contain proteins with either JRL or dirigent domain（s）. Altogether, our results identify OsJAC1 as a representative of a novel type of resistance protein derived from a plant lineage-specific gene fusion event for better function in local pathogen defense.
基金supported by the National Key Research and Development Program of China(2023ZD04073)the Major Project of Hubei Hongshan Laboratory(2022hszd016)+2 种基金the National Natural Science Foundation of China(32070284,32172421)the Key Research and Development Program of Hubei Province(2022BFE003)the Fundamental Research Funds for the Central Universities(2662023PY006).
文摘Engineering disease-resistant plants can be a powerful solution to the issue of food security.However,it requires addressing two fundamental questions:what genes to express and how to control their expressions.To find a solution,we screen CRISPR-edited upstream open reading frame(uORF)variants in rice,aiming to optimize translational control of disease-related genes.By switching uORF types of the 5′-leader from Arabidopsis TBF1,we modulate the ribosome accessibility to the downstream firefly luciferase.We assume that by switching uORF types using CRISPR,we could generate uORF variants with alternative translation efficiency(CRISPR-aTrE-uORF).These variants,capable of boosting translation for resistance-associated genes and dampening it for susceptible ones,can help pinpoint previously unidentified genes with optimal expression levels.To test the assumption,we screened edited uORF variants and found that enhanced translational suppression of the plastic glutamine synthetase 2 can provide broad-spectrum disease resistance in rice with minimal fitness costs.This strategy,which involves modifying uORFs from none to some,or from some to none or different ones,demonstrates how translational agriculture can speed up the development of disease-resistant crops.This is vital for tackling the food security challenges we face due to growing populations and changing climates.
基金funded by Research Program for Agricultural Science and Technology Development(PJ01570601)and the Fellowship Program(PJ01661001 and PJ01570601)of the National Institute of Agricultural Sciences,Rural Development Administration,Republic of Korea。
文摘Diverse bacterial and fungal pathogens attack plants,causing biotic stress and severe yield losses globally.These losses are expected to become more serious as climate change improves conditions for many pathogens.Therefore,identifying genes conferring broad-spectrum disease resistance and elucidating their underlying mechanisms provides important resources for plant breeding.WRKY transcription factors affect plant growth and stress responses.However,the functions of many WRKY proteins remain to be elucidated.Here,we demonstrated the role of rice(Oryza sativa)WRKY groupⅢtranscription factor OsWRKY65 in immunity.OsWRKY65 localized to the nucleus and acted as transcriptional repressor.Genetic and molecular functional analyses showed that OsWRKY65 increases resistance to the fungal pathogen Fusarium fujikuroi through downregulation of GA signaling and upregulation of JA signaling.Moreover,OsWRKY65 modulated the expression of the key genes that confer susceptibility or resistance to Xanthomonas oryzae pv.oryzae to enhance immunity against the pathogen.In particular,OsWRKY65directly bound to the promoter region of OsSWEET13 and repressed its expression.Taken together,our findings demonstrate that the OsWRKY65 enhances resistance to fungal and bacterial pathogens in rice.
基金Supported by Natural Science Foundation of Hebei Province(C2013301069)Financial Special Projects of Hebei Province(2012055004,2014055205,F16R2016024592)+2 种基金Key Technology Support Program of Hebei Province(16226303D-3)The Industry System of Hebei Province(HBCT2013030207)The State Key Laboratory of Cotton Biology(CB2016A19)~~
文摘NPR1 is an intersection of different disease resistance pathways and plays a key role in systemic-acquired resistance and induced systemic resistance. NPR1 regulates constitutive resistance and disease resistance determined by resistant genes. In this paper, the mechanism of disease resistance of NPR1 genes and its analogs were described. The research status and progress of NPR1 transgenic crops were systematically discussed. The application prospect of NPR1 transgenic crops was also forecasted.
基金supported by National Natural Science Foundation of China(30000112)Shanxi Province Natural Science Foundation(20001037).
文摘Systemic acquired resistance (SAR), known as the broad-spectrum, inducible plant immunity, is a defense response triggered by pathogen infection. The response starts from the recognition of plant resistance (R) with the corresponding avirulence (avr) gene from the pathogen. There are some genes for convergence of signals downstream of different R/avr interacting partners into a single signaling pathway. Salicylic acid (SA) is required for the induction of SAR and involved in transducing the signal in target tissues. The SA signal is transduced through NPR1, a nuclear-localized protein that interacts with transcription factors that are involved in regulating SA-mediated gene expression. Some chemicals that mimic natural signaling compounds can also activate SAR. The application of biochemical activators to agriculture for plant protection is a novel idea for developing green chemical pesticide.
