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
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
Genotype-by-environment interactions (GxE) are commonly observed for quantitative traits. In the present study, a doubled haploid (DH) population and its genetic linkage map were used to comparatively study QTLs in sa...Genotype-by-environment interactions (GxE) are commonly observed for quantitative traits. In the present study, a doubled haploid (DH) population and its genetic linkage map were used to comparatively study QTLs in salt stress and nonstress environments. A total of 24 QTLs were detected for five agronomic traits, which were distributed on all the chromosomes except 9 and 11. Under the salt stress, nine (37.5%) QTLs were detected, including one for 1 000-grain weight (GW), two for heading date (HD), one for plant height (PH), two for grains per panicle (GPP), and three for effective tillers (ET), while in the nonstress environment, 17 QTLs (70.8%) were detected, including five for GW, six for HD, three for PH, two for GPP, and one for ET. Two QTLs (8.3%) were consistently detected in both environments. One was identified on chromosome 4 for HD and the other on Chr.6 for GPP. Furthermore, three regions carrying multiple QTLs were identified on chromosomes 1, 4 and 8 respectively. For example, on chromosome 8, three QTLs for HD, GW and PH, respectively were identified between RG885-GA408 in nonstress environment, but not in the stress environment. The comparative study of QTLs detected in extremely different (salt stress and nonstress) environments revealed that there existed several QTLs for important agronomic traits on chromosome 8 which were affected significantly by salt stress.展开更多
Guanine nucleotide exchange factors(GEFs)and guanine nucleotide-dissociation inhibitors(GDIs)regulate small GTPase proteins,which function as molecular switches in various signaling pathways,but their identification a...Guanine nucleotide exchange factors(GEFs)and guanine nucleotide-dissociation inhibitors(GDIs)regulate small GTPase proteins,which function as molecular switches in various signaling pathways,but their identification and functions in plants are not well understood.Using in-silico analysis and transgenic approaches,respectively,we dissected the evolutionary relationships and functions of all GEF and GDI genes in rice.Intron-exon distribution and phylogenetic analyses identified 30 GEF and 10 GDI genes in rice that shared close evolutionary relationships with other eukaryotes.Tissue-specific expression and co-expression analyses revealed that phylogenetically related genes had similar expression patterns.GEF and GDI genes were highly expressed in panicles,hulls,and stamens.Co-expression network analysis identified panicle and stamen-specific modules of co-expressed genes in both families.Mapping of these genes in known protein interactomes further identified two and one small G-protein sub-networks.A mutant library of GEF and GDI families was constructed by CRISPR knockout of each gene,and their genotypes and phenotypes were confirmed.Phenotype changes occurred with the mutation of only three genes(OsGEF5,OsGDI1,and OsGEF3).OsGEF5 and OsGDI1 single mutants exhibited significantly reduced height and longer and thinner grains,whereas OsGEF3 mutants had reduced grain length compared to the wild type.Haplotype and eGWAS analyses showed that natural variations in the three genes affected gene expression in reproductive tissues that were significantly associated with the phenotypic variation.BiFC assays demonstrated that GDI1 and GEF3 interacted with grain-size protein GS3,pointing to a role of these genes in the regulation of grain size and plant architecture connected to heterotrimeric G-proteins in rice.展开更多
This study was conducted to examine the physicochemical characteristics and perform QTL mapping of genetic factors associated with the lipid content of rice. A rice strain with a high lipid content, “P31-2-2-2-B-B”,...This study was conducted to examine the physicochemical characteristics and perform QTL mapping of genetic factors associated with the lipid content of rice. A rice strain with a high lipid content, “P31-2-2-2-B-B”, was developed from mutants of “Dongjin” created by T-DNA insertion. The lipid content of “P31-2-2-2-B-B” brown rice was 4.42% whereas that of the donor cultivar “Dongjin” was 2.56%. The total fatty acid content of the high-lipid mutant brown rice was 7.82% and that of “Dongjin” was 3.43%. The unsaturated fatty acid composition of the mutant brown rice was 2.73% oleic acid, 2.74% linoleic acid, and 0.34% linolenic acid. In contrast, the fatty acid composition of the donor cultivar “Dongjin” was 1.30% oleic acid and 0.99% linoleic acid. The percentage of unsaturated fatty acid to total fatty acid in the high-lipid mutant was higher (74.3%) than that of “Dongjin” (66.8%). Continuous frequency distribution and transgressive segregation of the lipid content were observed in the F3 family (seeds) derived from a cross between the high-lipid mutant “P31-2-2-2-B-B” and a tongil-type cultivar “Samgang”. This result implied that the lipid content was a quantitative trait controlled by a polygene. Additionally, the broad sense heritability of lipid content was estimated to be 89.6% based on analysis of the F3 seeds. A significant QTL, qRLC5, was identified on chromosome 5 with a LOD score of 2.37, and was flanked by 5007 and 5014. Results of the present study should be useful for improving rice nutritional quality through marker-assisted selection.展开更多
Over 40% of the agricultural area in Brazil corresponds to no-tillage farming. Although it is evident the importance of obtaining upland rice cultivars adapted to this cropping system, researches in this sense are sti...Over 40% of the agricultural area in Brazil corresponds to no-tillage farming. Although it is evident the importance of obtaining upland rice cultivars adapted to this cropping system, researches in this sense are still incipient and breeders do not have cultivars available to recommend with enough security. The aim of this study was to evaluate phenotypic characters favorable to the no-tillage system in order to establish the basis for upland rice breeding programs interested in this cropping system. The seeds of twenty elite inbred lines from the Upland Rice Breeding Program from the Brazilian research institutions UFLA, EMBRAPA and EPAMIG were evaluated at the Central Seeds Lab from the Agriculture Department of UFLA following a randomized block design with four replicates. The characters evaluated were seedlings emergence (SE), green matter yield (GM), dry matter yield (DM), photosynthetic activity (PA), and superoxide dismutase activity (SOD). The quality parameters evaluated were obtained by a germination test (GT), germination first count (GFC), emergence test (E), initial stand (IS), and alpha-amylase expression. The lines CMG 2074, CMG 1967, CMG 2017, BRSMG Caravera and CMG 2097 showed higher SOD content in the enzymatic analyses, and consequently higher tolerance to abiotic stresses that could be caused by no-tillage. Considering the evaluation of agronomic traits, the line CMG 1967 showed the best performance in no-tillage soil and, therefore, should receive higher attention in Upland Rice Breeding Programs.展开更多
In the final stages of a plant breeding program, a crucial step is the multiplication of seeds in production fields. Besides a solid planning, the seeds multiplication needs a special attention to guarantee seeds with...In the final stages of a plant breeding program, a crucial step is the multiplication of seeds in production fields. Besides a solid planning, the seeds multiplication needs a special attention to guarantee seeds with high quality, genetic integrity, high germination and vigor to the farmer. The aim of this study was to evaluate the physiologic quality, enzymatic expression and respiratory activity of seeds of 20 elite upland rice lines adapted to the state of Minas Gerais, Brazil, from the upland rice breeding program from three Brazilians research institutions. The quality parameters evaluated were root protrusion, number of normal seedlings in the germination test, number of normal seedlings in the germination first count, initial stand from emergence test, speed of emergence index, seedlings shoot and root length, percentage of O2 and CO2 from respiratory activity and the expression pattern of the enzymes alcohol dehydrogenase (ADH) and malate dehydrogenase (MDH). The seeds quality varied among lines, allowing the selection of lines with best performance. The respiratory activity was lower in seeds of lines with high quality. The enzyme ADH was an excellent marker to infer about the quality of seeds, and the variation in the expression of MDH did not depend on the quality of rice seeds. The lines BRS Esmeralda, CMG1896 and CMG1509 showed high physiologic quality in their seeds, and therefore, they should receive higher attention in rice breeding programs.展开更多
A large number of adventitious buds were induced from in vitro cultured young inflorescences of haploids of rice.Having been subcultured on solidified subculture media at 26 ℃ for 7 days ,the adventitious buds we...A large number of adventitious buds were induced from in vitro cultured young inflorescences of haploids of rice.Having been subcultured on solidified subculture media at 26 ℃ for 7 days ,the adventitious buds were loaded into 1.8 mL plastic cryotubes with cryoprotectant and kept on ice for 45 60 min.After cooled at a rate of 1.0℃/min down to -40℃,the samples were kept in liquid nitrogen.The adventitious buds which have been cryopreserved for about 30 days were thawed rapidly in 38 40℃water and then plated on solidified MS medium containing 3 % sucrose,0.5 mg/L NAA and 2.0 mg/L kinetin.After plated, 23% 32 % of adventitious buds resumed growth and 15% 22 % regenerated plantlets.The results of this work indicated that the adventitious buds derived from in vitro cultured young inflorescences is a critical factor for the success and subculturing adventitious buds on MS medium containing 3% sucrose and 4% sorbitol or 20% potato extract is essential to the procedure.The effective cryoprotectant is 10 % DMSO(dimethyl sulfoximide)+0.5 mol/L sorbitol.展开更多
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 Chinese National Rice Genome Program and the National High-Tech Research Program of China.
文摘Genotype-by-environment interactions (GxE) are commonly observed for quantitative traits. In the present study, a doubled haploid (DH) population and its genetic linkage map were used to comparatively study QTLs in salt stress and nonstress environments. A total of 24 QTLs were detected for five agronomic traits, which were distributed on all the chromosomes except 9 and 11. Under the salt stress, nine (37.5%) QTLs were detected, including one for 1 000-grain weight (GW), two for heading date (HD), one for plant height (PH), two for grains per panicle (GPP), and three for effective tillers (ET), while in the nonstress environment, 17 QTLs (70.8%) were detected, including five for GW, six for HD, three for PH, two for GPP, and one for ET. Two QTLs (8.3%) were consistently detected in both environments. One was identified on chromosome 4 for HD and the other on Chr.6 for GPP. Furthermore, three regions carrying multiple QTLs were identified on chromosomes 1, 4 and 8 respectively. For example, on chromosome 8, three QTLs for HD, GW and PH, respectively were identified between RG885-GA408 in nonstress environment, but not in the stress environment. The comparative study of QTLs detected in extremely different (salt stress and nonstress) environments revealed that there existed several QTLs for important agronomic traits on chromosome 8 which were affected significantly by salt stress.
基金supported by the National Natural Science Foundation of China(32072042,31821005,32000370)Ten-Thousand Talents Programs,Fundamental Research Funds for the Central Universities(2662020SKPY006)+1 种基金Wuhan Applied Foundational Frontier Project(2020020601012257)Hubei Hongshan Laboratory(2021hszd005).
文摘Guanine nucleotide exchange factors(GEFs)and guanine nucleotide-dissociation inhibitors(GDIs)regulate small GTPase proteins,which function as molecular switches in various signaling pathways,but their identification and functions in plants are not well understood.Using in-silico analysis and transgenic approaches,respectively,we dissected the evolutionary relationships and functions of all GEF and GDI genes in rice.Intron-exon distribution and phylogenetic analyses identified 30 GEF and 10 GDI genes in rice that shared close evolutionary relationships with other eukaryotes.Tissue-specific expression and co-expression analyses revealed that phylogenetically related genes had similar expression patterns.GEF and GDI genes were highly expressed in panicles,hulls,and stamens.Co-expression network analysis identified panicle and stamen-specific modules of co-expressed genes in both families.Mapping of these genes in known protein interactomes further identified two and one small G-protein sub-networks.A mutant library of GEF and GDI families was constructed by CRISPR knockout of each gene,and their genotypes and phenotypes were confirmed.Phenotype changes occurred with the mutation of only three genes(OsGEF5,OsGDI1,and OsGEF3).OsGEF5 and OsGDI1 single mutants exhibited significantly reduced height and longer and thinner grains,whereas OsGEF3 mutants had reduced grain length compared to the wild type.Haplotype and eGWAS analyses showed that natural variations in the three genes affected gene expression in reproductive tissues that were significantly associated with the phenotypic variation.BiFC assays demonstrated that GDI1 and GEF3 interacted with grain-size protein GS3,pointing to a role of these genes in the regulation of grain size and plant architecture connected to heterotrimeric G-proteins in rice.
文摘This study was conducted to examine the physicochemical characteristics and perform QTL mapping of genetic factors associated with the lipid content of rice. A rice strain with a high lipid content, “P31-2-2-2-B-B”, was developed from mutants of “Dongjin” created by T-DNA insertion. The lipid content of “P31-2-2-2-B-B” brown rice was 4.42% whereas that of the donor cultivar “Dongjin” was 2.56%. The total fatty acid content of the high-lipid mutant brown rice was 7.82% and that of “Dongjin” was 3.43%. The unsaturated fatty acid composition of the mutant brown rice was 2.73% oleic acid, 2.74% linoleic acid, and 0.34% linolenic acid. In contrast, the fatty acid composition of the donor cultivar “Dongjin” was 1.30% oleic acid and 0.99% linoleic acid. The percentage of unsaturated fatty acid to total fatty acid in the high-lipid mutant was higher (74.3%) than that of “Dongjin” (66.8%). Continuous frequency distribution and transgressive segregation of the lipid content were observed in the F3 family (seeds) derived from a cross between the high-lipid mutant “P31-2-2-2-B-B” and a tongil-type cultivar “Samgang”. This result implied that the lipid content was a quantitative trait controlled by a polygene. Additionally, the broad sense heritability of lipid content was estimated to be 89.6% based on analysis of the F3 seeds. A significant QTL, qRLC5, was identified on chromosome 5 with a LOD score of 2.37, and was flanked by 5007 and 5014. Results of the present study should be useful for improving rice nutritional quality through marker-assisted selection.
文摘Over 40% of the agricultural area in Brazil corresponds to no-tillage farming. Although it is evident the importance of obtaining upland rice cultivars adapted to this cropping system, researches in this sense are still incipient and breeders do not have cultivars available to recommend with enough security. The aim of this study was to evaluate phenotypic characters favorable to the no-tillage system in order to establish the basis for upland rice breeding programs interested in this cropping system. The seeds of twenty elite inbred lines from the Upland Rice Breeding Program from the Brazilian research institutions UFLA, EMBRAPA and EPAMIG were evaluated at the Central Seeds Lab from the Agriculture Department of UFLA following a randomized block design with four replicates. The characters evaluated were seedlings emergence (SE), green matter yield (GM), dry matter yield (DM), photosynthetic activity (PA), and superoxide dismutase activity (SOD). The quality parameters evaluated were obtained by a germination test (GT), germination first count (GFC), emergence test (E), initial stand (IS), and alpha-amylase expression. The lines CMG 2074, CMG 1967, CMG 2017, BRSMG Caravera and CMG 2097 showed higher SOD content in the enzymatic analyses, and consequently higher tolerance to abiotic stresses that could be caused by no-tillage. Considering the evaluation of agronomic traits, the line CMG 1967 showed the best performance in no-tillage soil and, therefore, should receive higher attention in Upland Rice Breeding Programs.
文摘In the final stages of a plant breeding program, a crucial step is the multiplication of seeds in production fields. Besides a solid planning, the seeds multiplication needs a special attention to guarantee seeds with high quality, genetic integrity, high germination and vigor to the farmer. The aim of this study was to evaluate the physiologic quality, enzymatic expression and respiratory activity of seeds of 20 elite upland rice lines adapted to the state of Minas Gerais, Brazil, from the upland rice breeding program from three Brazilians research institutions. The quality parameters evaluated were root protrusion, number of normal seedlings in the germination test, number of normal seedlings in the germination first count, initial stand from emergence test, speed of emergence index, seedlings shoot and root length, percentage of O2 and CO2 from respiratory activity and the expression pattern of the enzymes alcohol dehydrogenase (ADH) and malate dehydrogenase (MDH). The seeds quality varied among lines, allowing the selection of lines with best performance. The respiratory activity was lower in seeds of lines with high quality. The enzyme ADH was an excellent marker to infer about the quality of seeds, and the variation in the expression of MDH did not depend on the quality of rice seeds. The lines BRS Esmeralda, CMG1896 and CMG1509 showed high physiologic quality in their seeds, and therefore, they should receive higher attention in rice breeding programs.
文摘A large number of adventitious buds were induced from in vitro cultured young inflorescences of haploids of rice.Having been subcultured on solidified subculture media at 26 ℃ for 7 days ,the adventitious buds were loaded into 1.8 mL plastic cryotubes with cryoprotectant and kept on ice for 45 60 min.After cooled at a rate of 1.0℃/min down to -40℃,the samples were kept in liquid nitrogen.The adventitious buds which have been cryopreserved for about 30 days were thawed rapidly in 38 40℃water and then plated on solidified MS medium containing 3 % sucrose,0.5 mg/L NAA and 2.0 mg/L kinetin.After plated, 23% 32 % of adventitious buds resumed growth and 15% 22 % regenerated plantlets.The results of this work indicated that the adventitious buds derived from in vitro cultured young inflorescences is a critical factor for the success and subculturing adventitious buds on MS medium containing 3% sucrose and 4% sorbitol or 20% potato extract is essential to the procedure.The effective cryoprotectant is 10 % DMSO(dimethyl sulfoximide)+0.5 mol/L sorbitol.
