Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an ...Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an eco-friendly and economical option.In the current study,F_(3) progenies derived from a cross of susceptible parent PMS-18-B(PAU 10845-1-1-1-1)×resistant parent RP Path 77(RP patho-17)were used to identify potential QTLs linked to BS resistance and to associate this resistance with a temporal spike in defense-related enzymes.展开更多
Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolera...Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolerance.However,endophytic bacterial communities in O.longistaminata and their plant growth-promoting(PGP)effects on the perennial rice of O.longistaminata offspring are poorly understood.In this study,the endophytic bacterial diversity,composition and network structures in the root,stem,and leaf tissues of O.longistaminata were characterized using Illumina sequencing of the 16S rRNA gene.The results suggested that O.longistaminata contains a multitude of niches for different endophytic bacteria,among which the root endosphere is more complex and functionally diverse than the stem and leaf endospheres.Tissue-specific biomarkers were identified,including Paludibaculum,Pseudactinotalea and Roseimarinus and others,for roots,Blautia for stems and Lachnospiraceae NK4A136 for leaves.The endophytic bacterial network of O.longistaminata was reassembled for various functions,including degradation/utilization/assimilation,detoxification,generation of precursor metabolites and energy,glycan pathways,macromolecule modification and metabolism.A total of 163 endophytic bacterial strains with PGP traits of potassium release,phosphate solubilization,nitrogen fixation,siderophore activity,indole-3-acetic acid(IAA)production,and 1-aminocyclopropane-1-carboxylate(ACC)deaminase activity were isolated from O.longistaminata.Eleven strains identified as Enterobacter cloacae,Enterobacter ludwigii,Stenotrophomonas maltophilia,Serratia fonticola,and Bacillus velezensis showed stable colonization abilities and PGP effects on perennial rice seedlings.Inoculated plants generally exhibited an enhanced root system and greater photosynthesis,biomass accumulation and nutrient uptake.Interestingly,two strains of E.cloacae have host genotype-dependent effects on perennial rice growth.The results of this study provide insights into the endophytic bacterial ecosystems of O.longistaminata,which can potentially be used as biofertilizers for sustainable perennial rice productivity.展开更多
Magnaporthe oryzae is the causal agent of rice blast. Glycosylation plays key roles in vegetative growth,development, and infection of M. oryzae. However, several glycosylation-related genes have not been characterize...Magnaporthe oryzae is the causal agent of rice blast. Glycosylation plays key roles in vegetative growth,development, and infection of M. oryzae. However, several glycosylation-related genes have not been characterized.In this study, we identified a Glyco_transf_22 domain-containing protein, MoAlg9, and found that MoAlg9 islocalized to the endoplasmic reticulum(ER). Deletion of MoALG9 significantly affected conidial production, normalappressorium formation, responses to stressors, and pathogenicity of M. oryzae. We also found that the ΔMoalg9mutant was defective in glycogen utilization, appressorial penetration, and invasive growth in host cells. Moreover,we further demonstrated that MoALG9 regulates the transcription of several target genes involved in conidiation,appressorium formation, and cell wall integrity. In addition, we found that the Glyco_transf_22 domain is essentialfor normal MoAlg9 function and localization. We also provide evidence that MoAlg9 is involved in N-glycosylationpathway in M. oryzae. Taken together, these results show that MoAlg9 is important for conidiation, appressoriumformation, maintenance of cell wall integrity, and the pathogenesis of M. oryzae.展开更多
Rice blast,caused by Magnaporthe oryzae,is a fungal disease that causes devastating damage to rice production worldwide.During infection,pathogens secrete effector proteins that modulate plant immunity.Disulfide bond ...Rice blast,caused by Magnaporthe oryzae,is a fungal disease that causes devastating damage to rice production worldwide.During infection,pathogens secrete effector proteins that modulate plant immunity.Disulfide bond formation catalyzed by protein disulfide isomerases(PDI)is essential for protein folding and maturation.However,the biological function of Pdi1 in M.oryzae has not yet been characterized.In this study,we identified the endoplasmic reticulum(ER)-located protein,MoPdi1,in M.oryzae.MoPdi1 regulates conidiation,cell wall stress,and pathogenicity of M.oryzae.Furthermore,the CGHC active sites in the a and a'redox domain of MoPdi1 were essential for the biological function of MoPDI1.Further tests demonstrated that MoPdi1 was involved in the regulation of ER stress and positively regulated ER phagy.We also found that MoPdi1 interacted with MoHut1.Deletion of MoPDI1 led to the bereft of MoHut1 dimerization,which depends on the formation of disulfide bonds.In addition,MoPdi1 affected the normal secretion of the cytoplasmic effector AVR-Pia.We provided evidence that MoHut1 is important for the vegetative growth,conidiation,and pathogenicity in M.oryzae.Therefore,our findings could provide a suitable target point for designing antifungal agrochemicals against rice blast fungus.展开更多
Xanthomonas oryzae pv.oryzae(Xoo)causes bacterial blight in rice,which reduces crop yield and leads to significant economic losses.Bacterial sigma(σ)factors are highly specialized proteins that allow RNA polymerase t...Xanthomonas oryzae pv.oryzae(Xoo)causes bacterial blight in rice,which reduces crop yield and leads to significant economic losses.Bacterial sigma(σ)factors are highly specialized proteins that allow RNA polymerase to recognize and bind to specific promoters.σ^(70) factors also regulate the expression of genes involved in stress response and virulence.However,the role of RpoD in Xoo is still unclear.In this study,we found thatσ^(70) factor RpoD is quite conservative among phytopathogenic bacteria,especially in Xanthomonas sp.In Xoo,PXO_RpoD plays an important role in oxidative stress tolerance and cell motility,as well as being essential for full virulence.Cleavage under targets and tagmentation(CUT&Tag)analyses indicated that RpoD mediates the type three secretion system(T3SS)by regulating the regulation of hrpG and hrpX.By performing bacterial one-hybrid and electrophoretic mobility assay(EMSA),we observed that RpoD directly bound to the promoters of hrpG and hrpX.Collectively,these results demonstrate the transcriptional mechanism and pathogenic functions of RpoD in regulating cell motility and oxidative stress response,providing novel insights into potential targets for disease control.展开更多
Bipolarpenoids A–J(1–10),ten undescribed ophiobolin-derived sesterterpenoids,were identified from the fungus Bipolaris oryzae.Their structures were elucidated by high resolution electrospray ionization mass spectrom...Bipolarpenoids A–J(1–10),ten undescribed ophiobolin-derived sesterterpenoids,were identified from the fungus Bipolaris oryzae.Their structures were elucidated by high resolution electrospray ionization mass spectrometry(HRESIMS),spectroscopic analyses,quantum chemical ^(13)C nuclear magnetic resonance(NMR),electronic circular dichroism(ECD)calculations,and single-crystal X-ray diffraction analyses.Notably,compounds 1 and 2 were uniquely characterized by a multicyclic caged pentacyclo[8.4.0.0^(1,5).0^(4,9).0^(7,11)]tetradecane-bridged system;compounds 4–6 featured unprecedented5/8/5/6 and 5/8/5/5 fused cores,respectively;compound 7 represented the first example of 3,4-secoophiobolin-alkaloid hybrid with a modified 5/6/8/5/5 fused carbon skeleton.Compound 9 showed potential anti-inflammatory effect in RAW264.7 macrophages and ulcerative colitis mice.展开更多
Rice grain size and chalkiness are important traits that influence grain yield and quality,respectively.Mining of genes for grain yield and appearance quality and clarification of their action modes are of great impor...Rice grain size and chalkiness are important traits that influence grain yield and quality,respectively.Mining of genes for grain yield and appearance quality and clarification of their action modes are of great importance in rice breeding.In this study,a rice protein disulfide isomerase-like enzyme PDIL2-3 was characterized.Expression analysis revealed that PDIL2-3 was highly expressed in endosperm and spikelet hulls.The PDIL2-3-cri lines generated by CRISPR/Cas9 technology exhibited a chalky grain phenotype with altered storage substance accumulation and increased grain size and weight,whereas exactly opposite results were obtained for PDIL2-3 overexpression lines.Cytological experiments revealed that PDIL2-3-cri increased rice seed length mainly by increasing the cell number and rice seed width mainly by increasing the cell size in grains,implying that PDIL2-3 regulates the grain size by influencing both cell division and expansion of spikelet hulls.Further flow cytometric analysis validated that PDIL2-3 has a negative effect on cell proliferation,preventing DNA duplication and cell division in spikelet hulls.Moreover,q RT-PCR results showed that the expression levels of genes related to cell cycle and storage substance synthesis were significantly changed in PDIL2-3-cri transgenic lines.Thus,our results indicated that PDIL2-3 plays a pivotal role in influencing grain size and quality of rice by affecting cell division/expansion and storage substance accumulation,providing new insights into the function of PDIL family members in rice and enriching the genetic resources for rice breeding.展开更多
Oxidation of self-stored carbohydrates and lipids provides the energy for the rapid morphogenetic transformation during asexual and infection-related development in Pyricularia oryzae,which results in intracellular ac...Oxidation of self-stored carbohydrates and lipids provides the energy for the rapid morphogenetic transformation during asexual and infection-related development in Pyricularia oryzae,which results in intracellular accumulation of reducing equivalents NADH and FADH_(2),requiring a cytosolic shuttling machinery towards mitochondria.Our previous studies identified the mitochondrial D-lactate dehydrogenase MoDld1 as a regulator to channel the metabolite flow in conjunction with redox homeostasis.However,the regulator(s)facilitating the cytosolic redox balance and the importance in propelling nutrient metabolite flow remain unknown.The G-3-P shuttle is a conserved machinery transporting the cytosolic reducing power to mitochondria.In P.oryzae,the mitochondrial G-3-P dehydrogenase Gpd2 was required for cellular NAD^(+)/NADH balance and fungal virulence.In this study,we relocate the mitochondrial G-3-P dehydrogenase Gpd2 to the cytosol for disturbing cytosolic redox status.Our results showed overexpression of cytosolic gpd2^(Δmts)without the mitochondrial targeted signal(MTS)driven by Ribosomal protein 27 promoter(PR27)exerted conflicting regulation of cellular oxidoreductase activities compared to theΔModld1 deletion mutant by RNA-seq and prevented the conidiation and pathogenicity of P.oryzae.Moreover,overexpression of gpd2^(Δmts)caused defects in glycogen and lipid mobilization underlying asexual and infectious structural development associated with decreased cellular NADH production and weakened anti-oxidation activities.RNA-seq and non-targeted metabolic profiling revealed down-regulated transcriptional activities of carbohydrate metabolism and lower abundance of fatty acids and secondary metabolites in RP27:gpd2^(Δmts).Thus,our studies indicate the essential role of cytosolic redox control in nutrient metabolism fueling the asexual and infection-related development in P.oryzae.展开更多
In this study,we searched for dispersed repeats(DRs)in the rice(Oryza sativa)genome using the iterative procedure(IP)method.The results revealed that the O.sativa genome contained 79 DR families,comprising 992739 DNA ...In this study,we searched for dispersed repeats(DRs)in the rice(Oryza sativa)genome using the iterative procedure(IP)method.The results revealed that the O.sativa genome contained 79 DR families,comprising 992739 DNA repeats,of which 496762 and 495977 were identified on the forward and reverse DNA strands,respectively.The detected DRs were,on average,374 bp in length and occupied 66.4%of the O.sativa genome.Totally 61%of DRs,identified by the IP method,overlapped with previously annotated dispersed repeats(ADRs)detected using the Extensive De Novo TE Annotator(EDTA)pipeline.展开更多
This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific ...This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific OsRALFs,suggesting that this evolutionary expansion could be the result of an arms race with pathogens.Among them,we focused on the Oryza-specific Os RALF26 and its closest homolog,OsRALF27,analyzing their effects across a range of plant species from monocots to dicots.The exogenous application of OsRALF26 significantly reduced bacterial populations in rice challenged with Xanthomonas oryzae pv.oryzae(Xoo)and in Arabidopsis and tomato challenged with Pseudomonas syringae pv.tomato DC3000(Pst DC3000),whereas Os RALF27 did not enhance resistance.展开更多
The polymerase chain reaction(PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR Green real-time PCR were developed to facilitate the simultaneous detection of three...The polymerase chain reaction(PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR Green real-time PCR were developed to facilitate the simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv.oryzae, X. oryzae pv. oryzicola, and Burkholderia glumae. The unique PCR primer sets were designed from portions of a putative glycosyltransferase gene of X. oryzae pv. oryzae, an Avr Rxo gene of X. oryzae pv. oryzicola, and an internal transcribed spacer(ITS) sequence of B. glumae. Using a multiplex PCR assay, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected in one PCR reaction that contained the newly developed primer set mix. Using SYBR Green real-time PCR assays, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected at 1, 1, and 10 fg μL-1, respectively. These newly designed molecular assays are sensitive and could be reliable tools for pathogen detection and disease forecasting.展开更多
Oryza sativa L. ssp. japonica and indica exhibit different sensitivity to photoinhibition and they show different stability of their core proteins D1 in the chloroplast photosystem Ⅱ. Using in situ hybridization, psb...Oryza sativa L. ssp. japonica and indica exhibit different sensitivity to photoinhibition and they show different stability of their core proteins D1 in the chloroplast photosystem Ⅱ. Using in situ hybridization, psbA, the gene encoding D1 protein of O. sativa ssp. japonica cv. 9516, and that of O. sativa ssp. indica cv. Shanyou 63 was cloned. As revealed by homology comparison of their sequences, the sequences are identical in the regions of promoter and 5′-UTR; differences are found in individual bases in the coding region all of which, being in the third position of respective codons, however, do not affect the amino acids coded finally; a difference is noted in the length of the oligo-U sequence in the region of 3′-UTR. It is thus apparent that, rather than a result of any difference in the amino acid sequences, the differences in the sensitivity to photoinhibition of D1 proteins between japonica and indica rice may be related to the upstream factors that regulate expression of psbA or to differences of photoprotective mechanisms.展开更多
Single-spore isolates were obtained from rice-growing fields of Yuan＇an in Hubei Province where rice blast seriously occurs in some years. DNA fingerprints were divided into 112 haplotypes and 14 lineages at 73% gene...Single-spore isolates were obtained from rice-growing fields of Yuan＇an in Hubei Province where rice blast seriously occurs in some years. DNA fingerprints were divided into 112 haplotypes and 14 lineages at 73% genetic similarity level. Among the lineages, no dominant lineages were found. The population genetic structures of Magnaporthe oryzae were not distinctly different in different years. The analysis also showed that there wasn＇t obvious simple relationship between patho- types and fingerprint groups.展开更多
基金supported by Punjab Agricultural University,Ludhiana,India,for providing the infrastructure and other facilities for conducting experiments.All other forms of support and financial assistance are duly acknowledged.
文摘Brown spot(BS)of rice,caused by Bipolaris oryzae,is a serious concern that not only causes quantitative losses but also affects grain quality.To manage this disease,the use of resistant genetic sources and QTLs is an eco-friendly and economical option.In the current study,F_(3) progenies derived from a cross of susceptible parent PMS-18-B(PAU 10845-1-1-1-1)×resistant parent RP Path 77(RP patho-17)were used to identify potential QTLs linked to BS resistance and to associate this resistance with a temporal spike in defense-related enzymes.
基金supported by funding from the National Natural Science Foundation of China(32060593 and 32060474)the Yunnan Provincial Science and Technology Department+4 种基金China(202101AT070021 and 202101AS070001)the Yunnan Provincial Department of Education Science Research Fund ProjectChina(2023J0006)the Graduate Innovation Project of Yunnan UniversityChina(KC-22223012 and ZC-22222760)。
文摘Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolerance.However,endophytic bacterial communities in O.longistaminata and their plant growth-promoting(PGP)effects on the perennial rice of O.longistaminata offspring are poorly understood.In this study,the endophytic bacterial diversity,composition and network structures in the root,stem,and leaf tissues of O.longistaminata were characterized using Illumina sequencing of the 16S rRNA gene.The results suggested that O.longistaminata contains a multitude of niches for different endophytic bacteria,among which the root endosphere is more complex and functionally diverse than the stem and leaf endospheres.Tissue-specific biomarkers were identified,including Paludibaculum,Pseudactinotalea and Roseimarinus and others,for roots,Blautia for stems and Lachnospiraceae NK4A136 for leaves.The endophytic bacterial network of O.longistaminata was reassembled for various functions,including degradation/utilization/assimilation,detoxification,generation of precursor metabolites and energy,glycan pathways,macromolecule modification and metabolism.A total of 163 endophytic bacterial strains with PGP traits of potassium release,phosphate solubilization,nitrogen fixation,siderophore activity,indole-3-acetic acid(IAA)production,and 1-aminocyclopropane-1-carboxylate(ACC)deaminase activity were isolated from O.longistaminata.Eleven strains identified as Enterobacter cloacae,Enterobacter ludwigii,Stenotrophomonas maltophilia,Serratia fonticola,and Bacillus velezensis showed stable colonization abilities and PGP effects on perennial rice seedlings.Inoculated plants generally exhibited an enhanced root system and greater photosynthesis,biomass accumulation and nutrient uptake.Interestingly,two strains of E.cloacae have host genotype-dependent effects on perennial rice growth.The results of this study provide insights into the endophytic bacterial ecosystems of O.longistaminata,which can potentially be used as biofertilizers for sustainable perennial rice productivity.
基金supported by the National Natural Science Foundation of China (32202253)the Natural Science Foundation of Anhui Higher Education Institutions, China (KJ2020A0102)the Talent Research Project of Anhui Agricultural University, China (rc342001)。
文摘Magnaporthe oryzae is the causal agent of rice blast. Glycosylation plays key roles in vegetative growth,development, and infection of M. oryzae. However, several glycosylation-related genes have not been characterized.In this study, we identified a Glyco_transf_22 domain-containing protein, MoAlg9, and found that MoAlg9 islocalized to the endoplasmic reticulum(ER). Deletion of MoALG9 significantly affected conidial production, normalappressorium formation, responses to stressors, and pathogenicity of M. oryzae. We also found that the ΔMoalg9mutant was defective in glycogen utilization, appressorial penetration, and invasive growth in host cells. Moreover,we further demonstrated that MoALG9 regulates the transcription of several target genes involved in conidiation,appressorium formation, and cell wall integrity. In addition, we found that the Glyco_transf_22 domain is essentialfor normal MoAlg9 function and localization. We also provide evidence that MoAlg9 is involved in N-glycosylationpathway in M. oryzae. Taken together, these results show that MoAlg9 is important for conidiation, appressoriumformation, maintenance of cell wall integrity, and the pathogenesis of M. oryzae.
基金supported by the National Natural Science Foundation of China(32202253)the Natural Science Foundation of Anhui Higher Education Institutions,China(KJ2020A0102)the Talent Research Project of Anhui Agricultural University,China(rc342001)。
文摘Rice blast,caused by Magnaporthe oryzae,is a fungal disease that causes devastating damage to rice production worldwide.During infection,pathogens secrete effector proteins that modulate plant immunity.Disulfide bond formation catalyzed by protein disulfide isomerases(PDI)is essential for protein folding and maturation.However,the biological function of Pdi1 in M.oryzae has not yet been characterized.In this study,we identified the endoplasmic reticulum(ER)-located protein,MoPdi1,in M.oryzae.MoPdi1 regulates conidiation,cell wall stress,and pathogenicity of M.oryzae.Furthermore,the CGHC active sites in the a and a'redox domain of MoPdi1 were essential for the biological function of MoPDI1.Further tests demonstrated that MoPdi1 was involved in the regulation of ER stress and positively regulated ER phagy.We also found that MoPdi1 interacted with MoHut1.Deletion of MoPDI1 led to the bereft of MoHut1 dimerization,which depends on the formation of disulfide bonds.In addition,MoPdi1 affected the normal secretion of the cytoplasmic effector AVR-Pia.We provided evidence that MoHut1 is important for the vegetative growth,conidiation,and pathogenicity in M.oryzae.Therefore,our findings could provide a suitable target point for designing antifungal agrochemicals against rice blast fungus.
基金supported by the National Natural Science Foundation of China(32072379,32001865 and 32202259)。
文摘Xanthomonas oryzae pv.oryzae(Xoo)causes bacterial blight in rice,which reduces crop yield and leads to significant economic losses.Bacterial sigma(σ)factors are highly specialized proteins that allow RNA polymerase to recognize and bind to specific promoters.σ^(70) factors also regulate the expression of genes involved in stress response and virulence.However,the role of RpoD in Xoo is still unclear.In this study,we found thatσ^(70) factor RpoD is quite conservative among phytopathogenic bacteria,especially in Xanthomonas sp.In Xoo,PXO_RpoD plays an important role in oxidative stress tolerance and cell motility,as well as being essential for full virulence.Cleavage under targets and tagmentation(CUT&Tag)analyses indicated that RpoD mediates the type three secretion system(T3SS)by regulating the regulation of hrpG and hrpX.By performing bacterial one-hybrid and electrophoretic mobility assay(EMSA),we observed that RpoD directly bound to the promoters of hrpG and hrpX.Collectively,these results demonstrate the transcriptional mechanism and pathogenic functions of RpoD in regulating cell motility and oxidative stress response,providing novel insights into potential targets for disease control.
基金financially supported by the National Key Research and Development Program of China(No.2021YFA0910500)the National Natural Science Foundation of China(Nos.U22A20380,82173706,and 82104028)+1 种基金the Fundamental Research Funds for the Central Universities(No.2024BRA018)the Science and Technology Major Project of Hubei Province(No.2021ACA012)。
文摘Bipolarpenoids A–J(1–10),ten undescribed ophiobolin-derived sesterterpenoids,were identified from the fungus Bipolaris oryzae.Their structures were elucidated by high resolution electrospray ionization mass spectrometry(HRESIMS),spectroscopic analyses,quantum chemical ^(13)C nuclear magnetic resonance(NMR),electronic circular dichroism(ECD)calculations,and single-crystal X-ray diffraction analyses.Notably,compounds 1 and 2 were uniquely characterized by a multicyclic caged pentacyclo[8.4.0.0^(1,5).0^(4,9).0^(7,11)]tetradecane-bridged system;compounds 4–6 featured unprecedented5/8/5/6 and 5/8/5/5 fused cores,respectively;compound 7 represented the first example of 3,4-secoophiobolin-alkaloid hybrid with a modified 5/6/8/5/5 fused carbon skeleton.Compound 9 showed potential anti-inflammatory effect in RAW264.7 macrophages and ulcerative colitis mice.
基金supported in part by grants from the National Natural Science Foundation of China(32472141,32101746,and 32102231)Natural Science Foundation of Hubei Province(JCZRLH202500540,2021CFB033,and 2022CFB393)。
文摘Rice grain size and chalkiness are important traits that influence grain yield and quality,respectively.Mining of genes for grain yield and appearance quality and clarification of their action modes are of great importance in rice breeding.In this study,a rice protein disulfide isomerase-like enzyme PDIL2-3 was characterized.Expression analysis revealed that PDIL2-3 was highly expressed in endosperm and spikelet hulls.The PDIL2-3-cri lines generated by CRISPR/Cas9 technology exhibited a chalky grain phenotype with altered storage substance accumulation and increased grain size and weight,whereas exactly opposite results were obtained for PDIL2-3 overexpression lines.Cytological experiments revealed that PDIL2-3-cri increased rice seed length mainly by increasing the cell number and rice seed width mainly by increasing the cell size in grains,implying that PDIL2-3 regulates the grain size by influencing both cell division and expansion of spikelet hulls.Further flow cytometric analysis validated that PDIL2-3 has a negative effect on cell proliferation,preventing DNA duplication and cell division in spikelet hulls.Moreover,q RT-PCR results showed that the expression levels of genes related to cell cycle and storage substance synthesis were significantly changed in PDIL2-3-cri transgenic lines.Thus,our results indicated that PDIL2-3 plays a pivotal role in influencing grain size and quality of rice by affecting cell division/expansion and storage substance accumulation,providing new insights into the function of PDIL family members in rice and enriching the genetic resources for rice breeding.
基金funded by the National Natural Science Foundation of China(32272513 and 31770156)the Natural Sciences and Engineering Research Council of Canada(Discovery Grant,RGPIN-2016-05356)the Canadian Foundation for Innovation(Discovery Grant,227398-2011)。
文摘Oxidation of self-stored carbohydrates and lipids provides the energy for the rapid morphogenetic transformation during asexual and infection-related development in Pyricularia oryzae,which results in intracellular accumulation of reducing equivalents NADH and FADH_(2),requiring a cytosolic shuttling machinery towards mitochondria.Our previous studies identified the mitochondrial D-lactate dehydrogenase MoDld1 as a regulator to channel the metabolite flow in conjunction with redox homeostasis.However,the regulator(s)facilitating the cytosolic redox balance and the importance in propelling nutrient metabolite flow remain unknown.The G-3-P shuttle is a conserved machinery transporting the cytosolic reducing power to mitochondria.In P.oryzae,the mitochondrial G-3-P dehydrogenase Gpd2 was required for cellular NAD^(+)/NADH balance and fungal virulence.In this study,we relocate the mitochondrial G-3-P dehydrogenase Gpd2 to the cytosol for disturbing cytosolic redox status.Our results showed overexpression of cytosolic gpd2^(Δmts)without the mitochondrial targeted signal(MTS)driven by Ribosomal protein 27 promoter(PR27)exerted conflicting regulation of cellular oxidoreductase activities compared to theΔModld1 deletion mutant by RNA-seq and prevented the conidiation and pathogenicity of P.oryzae.Moreover,overexpression of gpd2^(Δmts)caused defects in glycogen and lipid mobilization underlying asexual and infectious structural development associated with decreased cellular NADH production and weakened anti-oxidation activities.RNA-seq and non-targeted metabolic profiling revealed down-regulated transcriptional activities of carbohydrate metabolism and lower abundance of fatty acids and secondary metabolites in RP27:gpd2^(Δmts).Thus,our studies indicate the essential role of cytosolic redox control in nutrient metabolism fueling the asexual and infection-related development in P.oryzae.
基金supported by the Russian Science Foundation,Russia(Grant No.24-24-00031).
文摘In this study,we searched for dispersed repeats(DRs)in the rice(Oryza sativa)genome using the iterative procedure(IP)method.The results revealed that the O.sativa genome contained 79 DR families,comprising 992739 DNA repeats,of which 496762 and 495977 were identified on the forward and reverse DNA strands,respectively.The detected DRs were,on average,374 bp in length and occupied 66.4%of the O.sativa genome.Totally 61%of DRs,identified by the IP method,overlapped with previously annotated dispersed repeats(ADRs)detected using the Extensive De Novo TE Annotator(EDTA)pipeline.
基金supported by the National Research Foundation of Korea grant funded by the Korea government(Grant Nos.NRF-2020R1A2C1007778 and RS-2024-00454908)。
文摘This study explores the broad-spectrum application of OsRALF26,a small secreted peptide belonging to the rapid alkalinization factor(RALF)family in rice.We found that the rice genome carries numerous lineage-specific OsRALFs,suggesting that this evolutionary expansion could be the result of an arms race with pathogens.Among them,we focused on the Oryza-specific Os RALF26 and its closest homolog,OsRALF27,analyzing their effects across a range of plant species from monocots to dicots.The exogenous application of OsRALF26 significantly reduced bacterial populations in rice challenged with Xanthomonas oryzae pv.oryzae(Xoo)and in Arabidopsis and tomato challenged with Pseudomonas syringae pv.tomato DC3000(Pst DC3000),whereas Os RALF27 did not enhance resistance.
基金support of the National 863 Project (2012AA021601)the New Seedling program for graduate students of Zhejiang Province (2012R409012)
文摘The polymerase chain reaction(PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR Green real-time PCR were developed to facilitate the simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv.oryzae, X. oryzae pv. oryzicola, and Burkholderia glumae. The unique PCR primer sets were designed from portions of a putative glycosyltransferase gene of X. oryzae pv. oryzae, an Avr Rxo gene of X. oryzae pv. oryzicola, and an internal transcribed spacer(ITS) sequence of B. glumae. Using a multiplex PCR assay, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected in one PCR reaction that contained the newly developed primer set mix. Using SYBR Green real-time PCR assays, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected at 1, 1, and 10 fg μL-1, respectively. These newly designed molecular assays are sensitive and could be reliable tools for pathogen detection and disease forecasting.
文摘Oryza sativa L. ssp. japonica and indica exhibit different sensitivity to photoinhibition and they show different stability of their core proteins D1 in the chloroplast photosystem Ⅱ. Using in situ hybridization, psbA, the gene encoding D1 protein of O. sativa ssp. japonica cv. 9516, and that of O. sativa ssp. indica cv. Shanyou 63 was cloned. As revealed by homology comparison of their sequences, the sequences are identical in the regions of promoter and 5′-UTR; differences are found in individual bases in the coding region all of which, being in the third position of respective codons, however, do not affect the amino acids coded finally; a difference is noted in the length of the oligo-U sequence in the region of 3′-UTR. It is thus apparent that, rather than a result of any difference in the amino acid sequences, the differences in the sensitivity to photoinhibition of D1 proteins between japonica and indica rice may be related to the upstream factors that regulate expression of psbA or to differences of photoprotective mechanisms.
基金Supported by Competitive Project of Hubei Academy of Agricultural Sciences(2016jzxjh010)Major Research and Development Program of China(2016YFD0200807-1)~~
文摘Single-spore isolates were obtained from rice-growing fields of Yuan＇an in Hubei Province where rice blast seriously occurs in some years. DNA fingerprints were divided into 112 haplotypes and 14 lineages at 73% genetic similarity level. Among the lineages, no dominant lineages were found. The population genetic structures of Magnaporthe oryzae were not distinctly different in different years. The analysis also showed that there wasn＇t obvious simple relationship between patho- types and fingerprint groups.
