The development of resistant maize cultivars is the most effective and sustainable approach to combat fungal diseases.Over the last three decades,many quantitative trait loci(QTL)mapping studies reported numerous QTL ...The development of resistant maize cultivars is the most effective and sustainable approach to combat fungal diseases.Over the last three decades,many quantitative trait loci(QTL)mapping studies reported numerous QTL for fungal disease resistance(FDR)in maize.However,different genetic backgrounds of germplasm and differing QTL analysis algorithms limit the use of identified QTL for comparative studies.The meta-QTL(MQTL)analysis is the meta-analysis of multiple QTL experiments,which entails broader allelic coverage and helps in the combined analysis of diverse QTL mapping studies revealing common genomic regions for target traits.In the present study,128(33.59%)out of 381 reported QTL(from 82 studies)for FDR could be projected on the maize genome through MQTL analysis.It revealed 38 MQTL for FDR(12 diseases)on all chromosomes except chromosome 10.Five MQTL namely 1_4,2_4,3_2,3_4,and 5_4 were linked with multiple FDR.Total of 1910 candidate genes were identified for all the MQTL regions,with protein kinase gene families,TFs,pathogenesis-related,and disease-responsive proteins directly or indirectly associated with FDR.The comparison of physical positions of marker-traits association(MTAs)from genome-wide association studies with genes underlying MQTL interval verified the presence of QTL/candidate genes for particular diseases.The linked markers to MQTL and putative candidate genes underlying identified MQTL can be further validated in the germplasm through marker screening and expression studies.The study also attempted to unravel the underlying mechanism for FDR resistance by analyzing the constitutive gene network,which will be a useful resource to understand the molecular mechanism of defense-response of a particular disease and multiple FDR in maize.展开更多
Sugar is an indispensable source of energy for plant growth and development, and it requires the participation of sugar transporter proteins(STPs) for crossing the hydrophobic barrier in plants. Here, we systematicall...Sugar is an indispensable source of energy for plant growth and development, and it requires the participation of sugar transporter proteins(STPs) for crossing the hydrophobic barrier in plants. Here, we systematically identified the genes encoding sugar transporters in the genome of maize(Zea mays L.), analyzed their expression patterns under different conditions, and determined their functions in disease resistance. The results showed that the mazie sugar transporter family contained 24 members, all of which were predicted to be distributed on the cell membrane and had a highly conserved transmembrane transport domain. The tissue-specific expression of the maize sugar transporter genes was analyzed, and the expression level of these genes was found to be significantly different in different tissues. The analysis of biotic and abiotic stress data showed that the expression levels of the sugar transporter genes changed significantly under different stress factors. The expression levels of Zm STP2 and Zm STP20 continued to increase following Fusarium graminearum infection. By performing disease resistance analysis of zmstp2 and zmstp20 mutants, we found that after inoculation with Cochliobolus carbonum, Setosphaeria turcica, Cochliobolus heterostrophus, and F. graminearum, the lesion area of the mutants was significantly higher than that of the wild-type B73 plant. In this study, the genes encoding sugar transporters in maize were systematically identified and analyzed at the whole genome level. The expression patterns of the sugar transporter-encoding genes in different tissues of maize and under biotic and abiotic stresses were revealed, which laid an important theoretical foundation for further elucidation of their functions.展开更多
PCR detection,quantitative real-time PCR(q-RTPCR),outdoor insect resistance,and disease resistance identification were carried out for the detection of genetic stability and disease resistance through generations(T2,T...PCR detection,quantitative real-time PCR(q-RTPCR),outdoor insect resistance,and disease resistance identification were carried out for the detection of genetic stability and disease resistance through generations(T2,T3,and T4)in transgenic maize germplasms(S3002 and 349)containing the bivalent genes(insect resistance gene Cry1Ab13-1 and disease resistance gene NPR1)and their corresponding wild type.Results indicated that the target genes Cry1Ab13-1 and NPR1 were successfully transferred into both germplasms through tested generations;q-PCR confirmed the expression of Cry1Ab13-1 and NPR1 genes in roots,stems,and leaves of tested maize plants.In addition,S3002 and 349 bivalent gene-transformed lines exhibited resistance to large leaf spots and corn borer in the field evaluation compared to the wild type.Our study confirmed that Cry1Ab13-1 and NPR1 bivalent genes enhanced the resistance against maize borer and large leaf spot disease and can stably inherit.These findings could be exploited for improving other cultivated maize varieties.展开更多
Single nucleotide polymorphism(SNP)armays are a powerful genotyping tool used in genetic research and genomic breeding programs.Japanese flounder(Paralichthys olivaceus)is an economically-important aquaculture flatfis...Single nucleotide polymorphism(SNP)armays are a powerful genotyping tool used in genetic research and genomic breeding programs.Japanese flounder(Paralichthys olivaceus)is an economically-important aquaculture flatfish in many countries.However,the lack of high-efficient genotyping tools has impeded the genomic breeding programs for Japanese flounder.We developed a 50K Japanese flounder SNP array,"Yuxin No.1,"and report its utility in genomic selection(GS)for disease resistance to bacterial pathogens.We screened more than 42,.2 million SNPs from the whole-genome resequencing data of 1099 individuals and selected 48697 SNPs that were evenly distributed across the genome to anchor the array with Affymetrix Axiom genotyping technology.Evaluation of the array performance with 168 fishs howed that 74.7%of the loci were successfully genotyped with high call rates(>98%)and that the poly-morphic SNPs had good cluster separations.More than 85%of the SNPs were concordant with SNPs obtained from the whole-genome resequencing data.To validate"Yuxin No.1"for GS,the arrayed geno-typing data of 27 individuals from a candidate population and 931 individuals from a reference popula-tion were used to calculate the genomic estimated breeding values(GEBVs)for disease resistance toEdwardsiella tarda.There was a 21.2%relative increase in the accuracy of GEBV using the weighted geno-mic best linear unpiased prediction(wGBLUJP),compared to traditional pedigree-based best linear unbi-ased prediction(ABLUP),suggesting good performance of the'Yuxin No.1"SNP array for GS.In summary,we developed the"Yuxin No.1"50K SNP array,which provides a useful platform for high-quality geno-typing that may be beneficial to the genomic selective breeding of Japanese flounder.展开更多
[Objectives]To explore the effects of nano compound Chinese herbal medicine feed additive on growth performance,meat quality and disease resistance of chickens.[Methods]Chickens were fed with nano compound Chinese her...[Objectives]To explore the effects of nano compound Chinese herbal medicine feed additive on growth performance,meat quality and disease resistance of chickens.[Methods]Chickens were fed with nano compound Chinese herbal medicine feed additive developed by Hunan Polytechnic of Environment and Biology,including 120 chickens in the treatment group and 120 chickens in the control group(CK).The growth performance indices(body weight gain,feed to gain ratio and slaughter index),meat quality indices(pH value,color,drip loss,shear force)and disease resistance indices(morbidity and mortality)of the chickens in the treatment and CK groups were recorded and determined,respectively.[Results]The inclusion of 2%nano compound Chinese herbal medicine feed additive in the diet significantly increased the growth rate,reduced the feed-to-gain ratio and improved the meat quality of the chickens.Supplementing Chinese herbal medicine could increase the pH value and reduce the drip loss and shear force of chicken meat.At the same time,the body's immune function,antioxidant level and resistance against diseases of the chickens fed with nano compound Chinese herbal medicine feed additive were improved.[Conclusions]The inclusion of nano compound Chinese herbal medicine feed additive in the diet can improve the growth performance,meat quality and disease resistance of chickens.展开更多
Rice line 1892S is an elite thermo-sensitive genic male sterile(TGMS)line for two-line hybrid rice production.However,1892S is susceptible to rice blast,bacterial blight and submergence.Here we reported the introducti...Rice line 1892S is an elite thermo-sensitive genic male sterile(TGMS)line for two-line hybrid rice production.However,1892S is susceptible to rice blast,bacterial blight and submergence.Here we reported the introduction of blast resistance(R)gene Pi9,bacterial blight R gene Xa21 and submergence tolerance gene Sub1A into 1892S genetic background through backcrossing and marker-assisted selection.The improved TGMS line 31892S and its hybrids conferred disease resistance to rice blast and bacterial blight,and showed submergence tolerance for over 14 d without significant loss of viability.The sterility-fertility conversion of 31892S was similar to that of 1892S.31892S and its derived hybrid rice had similar agronomic traits and grain quality with 1892S and the control hybrid rice,respectively.The newly developed 31892S provided an improved TGMS line for two-line hybrid rice production with disease resistance to rice blast and bacterial blight,and submergence tolerance with no yield penalty or change in grain quality.展开更多
The emerging pests and phytopathogens have reduced the crop yield and quality, which hasthreatened the global food security. Traditional breeding methods, molecular marker-based breedingapproaches and use of genetical...The emerging pests and phytopathogens have reduced the crop yield and quality, which hasthreatened the global food security. Traditional breeding methods, molecular marker-based breedingapproaches and use of genetically modified crops have played a crucial role in strengthening the foodsecurity worldwide. However, their usages in crop improvement have been highly limited due to multiplecaveats. Genome editing tools like transcriptional activator-like effector nucleases and clustered regularlyinterspaced short palindromic repeats (CRISPR)-associated endonuclease Cas9 (CRISPR/Cas9) haveeffectively overcome limitations of the conventional breeding methods and are being widely accepted forimprovement of crops. Among the genome editing tools, the CRISPR/Cas9 system has emerged as themost powerful tool of genome editing because of its efficiency, amicability, flexibility, low cost andadaptability. Accumulated evidences indicate that genome editing has great potential in improving thedisease resistance in crop plants. In this review, we offered a brief introduction to the mechanisms of differentgenome editing systems and then discussed recent developments in CRISPR/Cas9 system-based genomeediting towards enhancement of rice disease resistance by different strategies. This review also discussed thepossible applications of recently developed genome editing approaches like CRISPR/Cas12a (formerlyknown as Cpf1) and base editors for enhancement of rice disease resistance.展开更多
Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it in...Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it increases the shelf life of the produce/products in addition to providing health benefits to consumers.Marker-assisted backcrossing(MABC)is the most successful approach to introgressing or pyramiding one or more traits using traitlinked markers.We used MABC to improve three popular Indian cultivars(GJG 9,GG 20,and GJGHPS 1)for foliar disease resistance(FDR)and high oleic acid content.A total of 22 BC3F4 and 30 BC2F4 introgression lines(ILs)for FDR and 46 BC3F4 and 41 BC2F4 ILs for high oleic acid were developed.Recurrent parent genome analysis using the 58 K Axiom_Arachis array identified several lines showing upto 94%of genome recovery among second and third backcross progenies.Phenotyping of these ILs revealed FDR scores comparable to the resistant parent,GPBD 4,and ILs with high(~80%)oleic acid in addition to high genome recovery.These ILs provide further opportunities for pyramiding FDR and high oleic acid in all three genetic backgrounds as well as for conducting multi-location yield trials for further evaluation and release for cultivation in target regions of India.展开更多
In agricultural production,a single insect-resistant and disease-resistant variety can no longer meet the demand.In this study,the expression vector pCAMBIA-3301-PR1 containing the disease-resistant gene PR1 was const...In agricultural production,a single insect-resistant and disease-resistant variety can no longer meet the demand.In this study,the expression vector pCAMBIA-3301-PR1 containing the disease-resistant gene PR1 was constructed by means of genetic engineering,and the PR1 gene was genetically transformed to contain the PR1 gene through the pollen tube method.In CryAb-8Like transgenic high-generation T7 receptor soybean,a new material that is resistant to insects and diseases is obtained.For T2 transformed plants,routine PCR detection,Southern Blot hybridization,fluorescence quantitative PCR detection,indoor and outdoor pest resistance identification and indoor disease resistance identification were performed.The results showed that there were 9 positive plants in the routine PCR test of T2 generation.In Southern Blot hybridization,both PR1 and CryAb-8Like genes are integrated in soybeans in the form of single copies.Fluorescence quantitative PCR showed that the expression levels of PR1 and CryAb-8Like genes are different in different tissues.The average expression levels of PR1 gene in plant roots,stems,and leaves are 2.88,1.54,and 5.26,respectively.CryAb-8Like genes are found in roots,stems,and leaves.The average expression levels were 1.36,1.39,and 4.25,respectively.The insectivorous rate of the CryAb-8Like gene in outdoor plants with positive insect resistance identification was 3.78%.The disc partition method was used indoors for pest resistance identification,and the bud length of transformed plants increased significantly.The average mortality rate of untransformed plants in indoor disease resistance identification was as high as 56.66%,and the average mortality rate of plants transformed with PR1 gene was 10.00%,and disease resistance was significantly improved.Therefore,a new material with resistance to diseases and insects is obtained.展开更多
Success in conventional breeding for resistance to mycotoxin-producing or other phytopathogenic fungi is dependent on the availability of resistance gene(s) in the germplasm.Even when it is available,breeding for dise...Success in conventional breeding for resistance to mycotoxin-producing or other phytopathogenic fungi is dependent on the availability of resistance gene(s) in the germplasm.Even when it is available,breeding for disease-resistant crops is very time consuming,especially in perennial crops such展开更多
Multi-strain probiotics provide the most dependable approaches to improve health,immune response,and disease resistance in farmed fishes.In the present study,we examined the effects of multi-species probiotics on the ...Multi-strain probiotics provide the most dependable approaches to improve health,immune response,and disease resistance in farmed fishes.In the present study,we examined the effects of multi-species probiotics on the survival,growth,immune response,and disease resistance of rohu(Labeo rohita)larvae.Newly hatched larvae from the day of first feeding(average weight of 0.003 g)were reared with multi-species probiotics having a combination of Bacillus subtilis(109 colony forming units(cfu)/mL)and Lactobacillus spp.(Lactobacillus plantarum,Lactobacillus buchneri-1011 cfu/mL)in water containing doses of 0(control-C),0.5 mL/L(treatment 1-T1),and 1.0 mL/L(treatment 2-T2)in triplicates for 90 days.After the experiment,a challenge test was performed to assess the fish's resistance to pathogenic Aeromonas veronii.Significantly higher survival was recorded in larvae of treated groups(87%in T2 and 79%in T1)compared to the control(62%).Significantly higher growth performance(weight gain and specific growth rate—SGR)was shown by the probiotic-treated larval groups compared to the control.Probiotic supplementation resulted in significantly higher counts of total viable colony(TVC)and lactic acid bacteria(LAB)in the intestine.Some immunological parameters(mucosal fold fattening,goblet cell abundance,expansion of lamina propria and enterocytes)of the gut were significantly better in probiotic-treated fish.The liver of treated fish showed irregular shape nuclei turning into regular shape and reducing spaces between the hepatic cells.Probiotic-treated fish had the highest post-challenge survival rate(90%)against A.veronii infection.The erythrocytes of challenged fish treated with probiotics had significantly lower frequencies of various nuclear and cellular abnormalities.These findings suggest that multi-species probiotic supplements could improve the survival,growth,health status,and immune response of rohu in the early stages of its development.展开更多
Dasypyrum villosum is one of the most valuable gene resources in wheat improvement,especially for disease resistance.The mining of favorable genes from D.villosum is frustrated by the lack of a whole genome sequence.I...Dasypyrum villosum is one of the most valuable gene resources in wheat improvement,especially for disease resistance.The mining of favorable genes from D.villosum is frustrated by the lack of a whole genome sequence.In this study,we generated a doubled-haploid line,91C43^(DH),using microspore culture and obtained a 4.05-GB high-quality,chromosome-scale genome assembly for D.villosum.The assembly contains39727 high-confidence genes,and 85.31% of the sequences are repetitive.Two reciprocal translocation events were detected,and 7VS-4VL is a unique translocation in D.villosum.The prolamin seed storage protein-coding genes were found to be duplicated;in particular,the genes encoding low-molecular-weight glutenin at the Glu-V3 locus were significantly expanded.RNA sequencing(RNA-seq)analysis indicated that,after Blumeria graminearum f.sp tritici(Bgt)inoculation,there were more upregulated genes involved in the pattern-triggered immunity and effector-triggered immunity defense pathways in D.villosum than in Triticum urartu.MNase hypersensitive sequencing(MH-seq)identified two Bgt-inducible MH sites(MHSs),one in the promoter and one in the 3'terminal region of the powdery mildew resistance(Pm)gene NLR1-V.Each site had two subpeaks and they were termed MHS1(MHS1.1/1.2)and MHS2(MHS2.1/2.2).Bgt-inducible MHS2.2 was uniquely present in D.villosum,and MHS1.1 was more inducible in D.villosum than in wheat,suggesting that MHSs may be critical for regulation of NLR1-V expression and plant defense.In summary,this study provides a valuable genome resource for functional genomics studies and wheat-D.villosum introgression breeding.The identified regulatory mechanisms may also be exploited to develop new strategies for enhancing Pm resistance by optimizing gene expression in wheat.展开更多
Facing a deteriorating natural environment and an increasing serious food crisis,bioengineering-based breeding is increasing in importance.To defend against pathogen infection,plants have evolved multiple defense mech...Facing a deteriorating natural environment and an increasing serious food crisis,bioengineering-based breeding is increasing in importance.To defend against pathogen infection,plants have evolved multiple defense mechanisms,including pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)and effector-triggered immunity(ETI).A complex regulatory network acts downstream of these PTI and ETI pathways,including hormone signal transduction and transcriptional reprogramming.In recent years,increasing lines of evidence show that epigenetic factors act,as key regulators involved in the transcriptional reprogramming,to modulate plant immune responses.Here,we summarize current progress on the regulatory mechanism of DNA methylation and histone modifications in plant defense responses.In addition,we also discuss the application of epigenetic mechanism-based resistance strategies in plant disease breeding.展开更多
The purpose of this study was to evaluate the potential of a host-associated Bacillus subtilis 1-C-7 as a probiotic for Chinese perch(Siniperca chuatsi).Four test diets were formulated to contain graded levels of B.su...The purpose of this study was to evaluate the potential of a host-associated Bacillus subtilis 1-C-7 as a probiotic for Chinese perch(Siniperca chuatsi).Four test diets were formulated to contain graded levels of B.subtilis 1-C-7 at 0(CY),0.85×10^(8)(Y1),0.95×10^(9)(Y2)and 0.91×10^(10)(Y3)CFU/kg diet.The test fish with initial weight 30.0±1.2 g were fed the 4 test diets with 3 replicates in an indoor water-flow aquaculture system with 12 net cages(40 fish/cage)for 10 wk.At the conclusion of the feeding trial,the probiotic effects of B.subtilis on Chinese perch were analyzed based on growth performance,serum biochemical indices,histologic morphology of liver and gut,gut microbiota and the resistance to Aero-monas hydrophila.The results showed that the percentage of weight gain had no significant change in the Y1 and Y2 groups(P>0.05)but decreased in the Y3 group compared to that in the CY group(P<0.05).The fish in the Y3 group displayed the highest activity of serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)among these 4 groups(P<0.05).The fish in the CY group had the highest value of malondialdehyde in the liver(P<0.05)and showed severe nuclear migration and vacuolization of hepatocytes.The morphology indicated that all test fish had poor intestinal health.However,the fish in the Y1 group had a relatively normal intestinal histologic structure.The mid gut microbial diversity analysis showed that dietary B.subtilis supplementation increased the abundance of probiotics such as Tenericutes and Bacteroides,whereas it reduced the abundance of pernicious bacteria such as Proteobacteria,Actinobacteria,Thermophilia and Spirochaetes.The challenge test showed that dietary B.subtilis supplementation increased the resistance to A.hydrophila in Chinese perch.In conclusion,dietary supplementation of 0.85×10^(8)CFU/kg B.subtilis 1-C-7 could improve the intestinal microbiota,intestinal health and disease resistance in Chinese perch,but more or excessive supple-mentation could reduce growth performance and have negative effects on health.展开更多
In contrast to large-effect qualitative disease resistance,quantitative disease resistance(QDR)exhibits partial and generally durable resistance and has been extensively utilized in crop breeding.The molecular mechani...In contrast to large-effect qualitative disease resistance,quantitative disease resistance(QDR)exhibits partial and generally durable resistance and has been extensively utilized in crop breeding.The molecular mechanisms underlying QDR remain largely unknown but considerable progress has been made in this area in recent years.In this review,we summarize the genes that have been associated with plant QDR and their biological functions.Many QDR genes belong to the canonical resistance gene categories with predicted functions in pathogen perception,signal transduction,phytohormone homeostasis,metabolite transport and biosynthesis,and epigenetic regulation.However,other"atypical"QDR genes are predicted to be involved in processes that are not commonly associated with disease resistance,such as vesicle trafficking,molecular chaperones,and others.This diversity of function for QDR genes contrasts with qualitative resistance,which is often based on the actions of nucleotidebinding leucine-rich repeat(NLR)resistance proteins.An understanding of the diversity of QDR mechanisms and of which mechanisms are effective against which classes of pathogens will enable the more effective deployment of QDR to produce more durably resistant,resilient crops.展开更多
As a famous fruit worldwide,citrus is susceptible to green mold caused by Penicillium digitatum,which causes large economic losses every year.e-Poly-L-lysine(e-PL)is a novel preservative with strong inhibitory effects...As a famous fruit worldwide,citrus is susceptible to green mold caused by Penicillium digitatum,which causes large economic losses every year.e-Poly-L-lysine(e-PL)is a novel preservative with strong inhibitory effects on fungi,and has the capacity to induce disease resistance in fruit,but the mechanism has been reported rarely,especially in citrus.In the present study,8ooμg/mL e-PL and P digitatum spores were inoculated in two different wounds on the citrus pericarp at an interval of 24 h.The results revealed that e-PL inhibited that the development of green mold without direct contact with P digitatum,indicating that the disease resistance of citrus was activated.Transcriptome analysis revealed that e-PL activated amino acid metabolism and phenylpropanoid biosynthesis.Besides,the accumulation of glutamic acid,proline,arginine,serine,lysine,phenylalanine,and tyrosine were changed during storage.In phenylpropanoid biosynthesis,-PL increased phenylalanine ammonia-lyase(PAL),cinnamate 4-hydroxylase(C4H),and 4-coumarate:coenzyme A ligase(4CL)activities and total phenolic and flavonoid contents.Importantly.among these phenolic compounds,e-PL promoted the accumulation of individual phenolic compounds including ferulic acid,chlorogenic acid,p-coumaric acid,caffeic acid,gallic acid,catechins,epicatechin,and narirutin.In conclusion,e-PL enhanced the resistance of citrus through amino acid metabolism and accumulation of phenolic compounds.These results improved the knowledge of the mechanism of-PL-induced disease resistance and provided a fresh theoretical basis for the use of e-PL in postharvest citrus preservation.展开更多
[Objectives]This study was conducted to establish simple, efficient, stable, standardized and practical identification methods for sugarcane resistance to white leaf disease(SCWL), and promote the breeding for sugarca...[Objectives]This study was conducted to establish simple, efficient, stable, standardized and practical identification methods for sugarcane resistance to white leaf disease(SCWL), and promote the breeding for sugarcane resistance to SCWL. [Methods]The identification technology of sugarcane resistance to SCWL was systematically studied and explored from the aspects of sugarcane material treatment and planting, inoculation liquid preparation, inoculation method, disease investigation, grading standard formulation, etc., and two sets of simple, efficient, stable, standardized and practical accurate identification methods for sugarcane resistance to SCWL were created for the first time, namely, the seed cane coating inoculation method and the stem-cutting inoculation method at the growth stage. The seed cane coating inoculation method includes the steps of directly screening SCWL phytoplasma, extracting juice from cane and adding 10 times of sterile water to prepare an inoculation liquid, spraying seed cane on plastic film to keep moisture, planting the inoculated materials in barrels in an insect-proof greenhouse for cultivation, investigating the incidence rate 30 d after inoculation, and evaluating the disease resistance according to the 1-5 level standard. The method of stem-cutting inoculation includes the steps of directly screening sugarcane stems carrying SCWL phytoplasma and adding 10 times of sterile water to prepare an inoculation liquid, cultivating the identification materials in an insect-proof greenhouse, dropping 100 μl of the inoculation liquid into each root incision with a pipette gun at the age of 6 months, investigating the incidence rate 20 d after planting, and evaluating the disease resistance according to the 1-5 level standard. [Results] The two methods are similar to the natural transmission method. After inoculation, SCML occurred significantly, with high sensitivity and good reproducibility. The results of resistance identification were consistent with those of natural disease in the field. Through the two inoculation methods and field natural disease investigation, the resistance of 10 main cultivars to SCML was identified, which was true and reliable. [Conclusions] This study can provide standard varieties for identification of SCML resistance in the future.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
WRKY transcription factors,transcriptional regulators unique to plants,play an important role in defense response to pathogen infection.However,the resistance mechanisms of WRKY genes in sugarcane remain unclear.In th...WRKY transcription factors,transcriptional regulators unique to plants,play an important role in defense response to pathogen infection.However,the resistance mechanisms of WRKY genes in sugarcane remain unclear.In the present study,gene ontology(GO)enrichment analysis revealed that WRKY gene family in sugarcane was extensively involved in the response to biotic stress and in defense response.We identified gene ScWRKY4,a classⅡc member of the WRKY gene family,in sugarcane cultivar ROC22.This gene was induced by salicylic acid(SA)and methyl jasmonate(MeJA)stress.Interestingly,expression of ScWRKY4 was down-regulated in smut-resistant sugarcane cultivars but up-regulated in smutsusceptible sugarcane cultivars infected with Sporisorium scitamineum.Moreover,stable overexpression of the ScWRKY4 gene in Nicotiana benthamiana enhanced susceptibility to Fusarium solani var.coeruleum and caused down-regulated expression of immune marker-related genes.Transcriptome analysis indicated suppressed expression of most JAZ genes in the signal transduction pathway.ScWRKY4 interacted with ScJAZ13 to repress its expression.We thus hypothesized that the ScWRKY4 gene was involved in the regulatory network of plant disease resistance,most likely through the JA signaling pathway.The present study depicting the molecular involvement of ScWRKY4 in sugarcane disease resistance lays a foundation for future investigation.展开更多
Natural alleles controlling multiple disease resistances (MDR) are valuable for crop breeding. However, only one MDR gene have been cloned in maize, and molecular mechanisms of MDR are not clear. By map-based cloning,...Natural alleles controlling multiple disease resistances (MDR) are valuable for crop breeding. However, only one MDR gene have been cloned in maize, and molecular mechanisms of MDR are not clear. By map-based cloning, we have cloned a teosinte-derived allele of a resistance gene, Mexicana lesion mimic 1 (ZmMM1), which has a lesion mimic phenotype and confers resistance to northern leaf blight (NLB), gray leaf spot (GLS) and southern corn rust (SCR). Strong MDR conferred by the teosinte allele is linked with the polymorphisms in the 3' untranslated region of the ZmMM1 gene that cause increased accumulation of ZmMM1 protein. ZmMM1 acts as a transcription repressor and negatively regulates transcription of specific target genes including ZmMM1-target gene 3 (ZmMT3), which functions as a negative regulator of plant immunity and associated cell death. The successful isolation of the ZmMM1 resistance gene will help not only in developing broad-spectrum and durable disease resistance but also in understanding the molecular mechanisms underlying MDR.展开更多
基金supported by Indian Council of Agricultural Research(ICAR),New Delhi for assistance.
文摘The development of resistant maize cultivars is the most effective and sustainable approach to combat fungal diseases.Over the last three decades,many quantitative trait loci(QTL)mapping studies reported numerous QTL for fungal disease resistance(FDR)in maize.However,different genetic backgrounds of germplasm and differing QTL analysis algorithms limit the use of identified QTL for comparative studies.The meta-QTL(MQTL)analysis is the meta-analysis of multiple QTL experiments,which entails broader allelic coverage and helps in the combined analysis of diverse QTL mapping studies revealing common genomic regions for target traits.In the present study,128(33.59%)out of 381 reported QTL(from 82 studies)for FDR could be projected on the maize genome through MQTL analysis.It revealed 38 MQTL for FDR(12 diseases)on all chromosomes except chromosome 10.Five MQTL namely 1_4,2_4,3_2,3_4,and 5_4 were linked with multiple FDR.Total of 1910 candidate genes were identified for all the MQTL regions,with protein kinase gene families,TFs,pathogenesis-related,and disease-responsive proteins directly or indirectly associated with FDR.The comparison of physical positions of marker-traits association(MTAs)from genome-wide association studies with genes underlying MQTL interval verified the presence of QTL/candidate genes for particular diseases.The linked markers to MQTL and putative candidate genes underlying identified MQTL can be further validated in the germplasm through marker screening and expression studies.The study also attempted to unravel the underlying mechanism for FDR resistance by analyzing the constitutive gene network,which will be a useful resource to understand the molecular mechanism of defense-response of a particular disease and multiple FDR in maize.
基金supported by the National Natural Science Foundation of China (31901864)the State Key Laboratory of North China Crop Improvement and Regulation (NCCIR2020ZZ-9)+3 种基金the Research Project of Science and Technology in Universities of Hebei Province, China (BJK2022006)the earmarked fund for China Agriculture Research System (CARS-02)the Key Research and Development Projects of Hebei (19226503D)the Central Government Guides Local Science and Technology Development Projects, China (216Z6501G and 216Z6502G)。
文摘Sugar is an indispensable source of energy for plant growth and development, and it requires the participation of sugar transporter proteins(STPs) for crossing the hydrophobic barrier in plants. Here, we systematically identified the genes encoding sugar transporters in the genome of maize(Zea mays L.), analyzed their expression patterns under different conditions, and determined their functions in disease resistance. The results showed that the mazie sugar transporter family contained 24 members, all of which were predicted to be distributed on the cell membrane and had a highly conserved transmembrane transport domain. The tissue-specific expression of the maize sugar transporter genes was analyzed, and the expression level of these genes was found to be significantly different in different tissues. The analysis of biotic and abiotic stress data showed that the expression levels of the sugar transporter genes changed significantly under different stress factors. The expression levels of Zm STP2 and Zm STP20 continued to increase following Fusarium graminearum infection. By performing disease resistance analysis of zmstp2 and zmstp20 mutants, we found that after inoculation with Cochliobolus carbonum, Setosphaeria turcica, Cochliobolus heterostrophus, and F. graminearum, the lesion area of the mutants was significantly higher than that of the wild-type B73 plant. In this study, the genes encoding sugar transporters in maize were systematically identified and analyzed at the whole genome level. The expression patterns of the sugar transporter-encoding genes in different tissues of maize and under biotic and abiotic stresses were revealed, which laid an important theoretical foundation for further elucidation of their functions.
基金supported by the National Key Research and Development Program of China(2019YFD1002603-1)。
文摘PCR detection,quantitative real-time PCR(q-RTPCR),outdoor insect resistance,and disease resistance identification were carried out for the detection of genetic stability and disease resistance through generations(T2,T3,and T4)in transgenic maize germplasms(S3002 and 349)containing the bivalent genes(insect resistance gene Cry1Ab13-1 and disease resistance gene NPR1)and their corresponding wild type.Results indicated that the target genes Cry1Ab13-1 and NPR1 were successfully transferred into both germplasms through tested generations;q-PCR confirmed the expression of Cry1Ab13-1 and NPR1 genes in roots,stems,and leaves of tested maize plants.In addition,S3002 and 349 bivalent gene-transformed lines exhibited resistance to large leaf spots and corn borer in the field evaluation compared to the wild type.Our study confirmed that Cry1Ab13-1 and NPR1 bivalent genes enhanced the resistance against maize borer and large leaf spot disease and can stably inherit.These findings could be exploited for improving other cultivated maize varieties.
文摘Single nucleotide polymorphism(SNP)armays are a powerful genotyping tool used in genetic research and genomic breeding programs.Japanese flounder(Paralichthys olivaceus)is an economically-important aquaculture flatfish in many countries.However,the lack of high-efficient genotyping tools has impeded the genomic breeding programs for Japanese flounder.We developed a 50K Japanese flounder SNP array,"Yuxin No.1,"and report its utility in genomic selection(GS)for disease resistance to bacterial pathogens.We screened more than 42,.2 million SNPs from the whole-genome resequencing data of 1099 individuals and selected 48697 SNPs that were evenly distributed across the genome to anchor the array with Affymetrix Axiom genotyping technology.Evaluation of the array performance with 168 fishs howed that 74.7%of the loci were successfully genotyped with high call rates(>98%)and that the poly-morphic SNPs had good cluster separations.More than 85%of the SNPs were concordant with SNPs obtained from the whole-genome resequencing data.To validate"Yuxin No.1"for GS,the arrayed geno-typing data of 27 individuals from a candidate population and 931 individuals from a reference popula-tion were used to calculate the genomic estimated breeding values(GEBVs)for disease resistance toEdwardsiella tarda.There was a 21.2%relative increase in the accuracy of GEBV using the weighted geno-mic best linear unpiased prediction(wGBLUJP),compared to traditional pedigree-based best linear unbi-ased prediction(ABLUP),suggesting good performance of the'Yuxin No.1"SNP array for GS.In summary,we developed the"Yuxin No.1"50K SNP array,which provides a useful platform for high-quality geno-typing that may be beneficial to the genomic selective breeding of Japanese flounder.
基金Project of Hunan Province for Science of Education during 13th Five-Year Plan Period[XJK18BZY066]Hengyang Social Science Foundation Project[2017B(1)010].
文摘[Objectives]To explore the effects of nano compound Chinese herbal medicine feed additive on growth performance,meat quality and disease resistance of chickens.[Methods]Chickens were fed with nano compound Chinese herbal medicine feed additive developed by Hunan Polytechnic of Environment and Biology,including 120 chickens in the treatment group and 120 chickens in the control group(CK).The growth performance indices(body weight gain,feed to gain ratio and slaughter index),meat quality indices(pH value,color,drip loss,shear force)and disease resistance indices(morbidity and mortality)of the chickens in the treatment and CK groups were recorded and determined,respectively.[Results]The inclusion of 2%nano compound Chinese herbal medicine feed additive in the diet significantly increased the growth rate,reduced the feed-to-gain ratio and improved the meat quality of the chickens.Supplementing Chinese herbal medicine could increase the pH value and reduce the drip loss and shear force of chicken meat.At the same time,the body's immune function,antioxidant level and resistance against diseases of the chickens fed with nano compound Chinese herbal medicine feed additive were improved.[Conclusions]The inclusion of nano compound Chinese herbal medicine feed additive in the diet can improve the growth performance,meat quality and disease resistance of chickens.
文摘Rice line 1892S is an elite thermo-sensitive genic male sterile(TGMS)line for two-line hybrid rice production.However,1892S is susceptible to rice blast,bacterial blight and submergence.Here we reported the introduction of blast resistance(R)gene Pi9,bacterial blight R gene Xa21 and submergence tolerance gene Sub1A into 1892S genetic background through backcrossing and marker-assisted selection.The improved TGMS line 31892S and its hybrids conferred disease resistance to rice blast and bacterial blight,and showed submergence tolerance for over 14 d without significant loss of viability.The sterility-fertility conversion of 31892S was similar to that of 1892S.31892S and its derived hybrid rice had similar agronomic traits and grain quality with 1892S and the control hybrid rice,respectively.The newly developed 31892S provided an improved TGMS line for two-line hybrid rice production with disease resistance to rice blast and bacterial blight,and submergence tolerance with no yield penalty or change in grain quality.
基金the China Priority Program-Breeding of Seven Major Crops(Grant No.2017YFD01100100)the Innovation Program of Chinese Academy of Agricultural Sciences(Grant No.01-ICS)the Talented Young Scientist Program of China(Grant No.India-17-01).
文摘The emerging pests and phytopathogens have reduced the crop yield and quality, which hasthreatened the global food security. Traditional breeding methods, molecular marker-based breedingapproaches and use of genetically modified crops have played a crucial role in strengthening the foodsecurity worldwide. However, their usages in crop improvement have been highly limited due to multiplecaveats. Genome editing tools like transcriptional activator-like effector nucleases and clustered regularlyinterspaced short palindromic repeats (CRISPR)-associated endonuclease Cas9 (CRISPR/Cas9) haveeffectively overcome limitations of the conventional breeding methods and are being widely accepted forimprovement of crops. Among the genome editing tools, the CRISPR/Cas9 system has emerged as themost powerful tool of genome editing because of its efficiency, amicability, flexibility, low cost andadaptability. Accumulated evidences indicate that genome editing has great potential in improving thedisease resistance in crop plants. In this review, we offered a brief introduction to the mechanisms of differentgenome editing systems and then discussed recent developments in CRISPR/Cas9 system-based genomeediting towards enhancement of rice disease resistance by different strategies. This review also discussed thepossible applications of recently developed genome editing approaches like CRISPR/Cas12a (formerlyknown as Cpf1) and base editors for enhancement of rice disease resistance.
基金sponsored by Department of Agriculture and Co-operation and Farmer Welfare(DAC&FW),Ministry of Agriculture,Government of India and Mars Wrigley,USAthe award of Junior/Senior Research Fellowship from Department of Biotechnology,Government of Indiapart of the CGIAR Research Program on Grain Legumes and Dryland Cereals(GLDC)
文摘Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it increases the shelf life of the produce/products in addition to providing health benefits to consumers.Marker-assisted backcrossing(MABC)is the most successful approach to introgressing or pyramiding one or more traits using traitlinked markers.We used MABC to improve three popular Indian cultivars(GJG 9,GG 20,and GJGHPS 1)for foliar disease resistance(FDR)and high oleic acid content.A total of 22 BC3F4 and 30 BC2F4 introgression lines(ILs)for FDR and 46 BC3F4 and 41 BC2F4 ILs for high oleic acid were developed.Recurrent parent genome analysis using the 58 K Axiom_Arachis array identified several lines showing upto 94%of genome recovery among second and third backcross progenies.Phenotyping of these ILs revealed FDR scores comparable to the resistant parent,GPBD 4,and ILs with high(~80%)oleic acid in addition to high genome recovery.These ILs provide further opportunities for pyramiding FDR and high oleic acid in all three genetic backgrounds as well as for conducting multi-location yield trials for further evaluation and release for cultivation in target regions of India.
基金the National Major Special Project for Breeding New Varieties of Genetically Modified Organisms(2016ZX08004-004).
文摘In agricultural production,a single insect-resistant and disease-resistant variety can no longer meet the demand.In this study,the expression vector pCAMBIA-3301-PR1 containing the disease-resistant gene PR1 was constructed by means of genetic engineering,and the PR1 gene was genetically transformed to contain the PR1 gene through the pollen tube method.In CryAb-8Like transgenic high-generation T7 receptor soybean,a new material that is resistant to insects and diseases is obtained.For T2 transformed plants,routine PCR detection,Southern Blot hybridization,fluorescence quantitative PCR detection,indoor and outdoor pest resistance identification and indoor disease resistance identification were performed.The results showed that there were 9 positive plants in the routine PCR test of T2 generation.In Southern Blot hybridization,both PR1 and CryAb-8Like genes are integrated in soybeans in the form of single copies.Fluorescence quantitative PCR showed that the expression levels of PR1 and CryAb-8Like genes are different in different tissues.The average expression levels of PR1 gene in plant roots,stems,and leaves are 2.88,1.54,and 5.26,respectively.CryAb-8Like genes are found in roots,stems,and leaves.The average expression levels were 1.36,1.39,and 4.25,respectively.The insectivorous rate of the CryAb-8Like gene in outdoor plants with positive insect resistance identification was 3.78%.The disc partition method was used indoors for pest resistance identification,and the bud length of transformed plants increased significantly.The average mortality rate of untransformed plants in indoor disease resistance identification was as high as 56.66%,and the average mortality rate of plants transformed with PR1 gene was 10.00%,and disease resistance was significantly improved.Therefore,a new material with resistance to diseases and insects is obtained.
文摘Success in conventional breeding for resistance to mycotoxin-producing or other phytopathogenic fungi is dependent on the availability of resistance gene(s) in the germplasm.Even when it is available,breeding for disease-resistant crops is very time consuming,especially in perennial crops such
基金Krishi Gobeshona Foundation,Bangladesh Agricultural Research Council,Dhaka,supported a grant(CGP TF 75-F/20)the corresponding author.Bangladesh Agricultural University Research System(BAURES)is gratefully acknowledged for the financial management of this project(Project No.2020/954/KGF).
文摘Multi-strain probiotics provide the most dependable approaches to improve health,immune response,and disease resistance in farmed fishes.In the present study,we examined the effects of multi-species probiotics on the survival,growth,immune response,and disease resistance of rohu(Labeo rohita)larvae.Newly hatched larvae from the day of first feeding(average weight of 0.003 g)were reared with multi-species probiotics having a combination of Bacillus subtilis(109 colony forming units(cfu)/mL)and Lactobacillus spp.(Lactobacillus plantarum,Lactobacillus buchneri-1011 cfu/mL)in water containing doses of 0(control-C),0.5 mL/L(treatment 1-T1),and 1.0 mL/L(treatment 2-T2)in triplicates for 90 days.After the experiment,a challenge test was performed to assess the fish's resistance to pathogenic Aeromonas veronii.Significantly higher survival was recorded in larvae of treated groups(87%in T2 and 79%in T1)compared to the control(62%).Significantly higher growth performance(weight gain and specific growth rate—SGR)was shown by the probiotic-treated larval groups compared to the control.Probiotic supplementation resulted in significantly higher counts of total viable colony(TVC)and lactic acid bacteria(LAB)in the intestine.Some immunological parameters(mucosal fold fattening,goblet cell abundance,expansion of lamina propria and enterocytes)of the gut were significantly better in probiotic-treated fish.The liver of treated fish showed irregular shape nuclei turning into regular shape and reducing spaces between the hepatic cells.Probiotic-treated fish had the highest post-challenge survival rate(90%)against A.veronii infection.The erythrocytes of challenged fish treated with probiotics had significantly lower frequencies of various nuclear and cellular abnormalities.These findings suggest that multi-species probiotic supplements could improve the survival,growth,health status,and immune response of rohu in the early stages of its development.
基金financially supported by the National Key Agriculture Projects(NK2022060101)National Key Research and Development Program(2022YFF1002900,2020YFE0202900)+3 种基金the Fundamental Research Funds for the Central University(XUEKEN2022012)Jiangsu Provincial Key Research and Development Program(BE2021375,BE2022346)Seed Industry Revitalization Project of Jiangsu Province(JBGS2021006,2021013,2021047)Joint Research of Improved Wheat Variety of Anhui,and Jiangsu Agricultural Technology System(JATS)(JATS[2021]463,JATS[2022]464).
文摘Dasypyrum villosum is one of the most valuable gene resources in wheat improvement,especially for disease resistance.The mining of favorable genes from D.villosum is frustrated by the lack of a whole genome sequence.In this study,we generated a doubled-haploid line,91C43^(DH),using microspore culture and obtained a 4.05-GB high-quality,chromosome-scale genome assembly for D.villosum.The assembly contains39727 high-confidence genes,and 85.31% of the sequences are repetitive.Two reciprocal translocation events were detected,and 7VS-4VL is a unique translocation in D.villosum.The prolamin seed storage protein-coding genes were found to be duplicated;in particular,the genes encoding low-molecular-weight glutenin at the Glu-V3 locus were significantly expanded.RNA sequencing(RNA-seq)analysis indicated that,after Blumeria graminearum f.sp tritici(Bgt)inoculation,there were more upregulated genes involved in the pattern-triggered immunity and effector-triggered immunity defense pathways in D.villosum than in Triticum urartu.MNase hypersensitive sequencing(MH-seq)identified two Bgt-inducible MH sites(MHSs),one in the promoter and one in the 3'terminal region of the powdery mildew resistance(Pm)gene NLR1-V.Each site had two subpeaks and they were termed MHS1(MHS1.1/1.2)and MHS2(MHS2.1/2.2).Bgt-inducible MHS2.2 was uniquely present in D.villosum,and MHS1.1 was more inducible in D.villosum than in wheat,suggesting that MHSs may be critical for regulation of NLR1-V expression and plant defense.In summary,this study provides a valuable genome resource for functional genomics studies and wheat-D.villosum introgression breeding.The identified regulatory mechanisms may also be exploited to develop new strategies for enhancing Pm resistance by optimizing gene expression in wheat.
基金supported by a grant from the National Natural Science Foundation of China(32270200 to CGD).
文摘Facing a deteriorating natural environment and an increasing serious food crisis,bioengineering-based breeding is increasing in importance.To defend against pathogen infection,plants have evolved multiple defense mechanisms,including pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)and effector-triggered immunity(ETI).A complex regulatory network acts downstream of these PTI and ETI pathways,including hormone signal transduction and transcriptional reprogramming.In recent years,increasing lines of evidence show that epigenetic factors act,as key regulators involved in the transcriptional reprogramming,to modulate plant immune responses.Here,we summarize current progress on the regulatory mechanism of DNA methylation and histone modifications in plant defense responses.In addition,we also discuss the application of epigenetic mechanism-based resistance strategies in plant disease breeding.
基金supported by the Fund of Fujian Key Laboratory of Functional Aquafeed and Culture Environment Control(FACE20200004)and China Agriculture Research System(CARS-46).
文摘The purpose of this study was to evaluate the potential of a host-associated Bacillus subtilis 1-C-7 as a probiotic for Chinese perch(Siniperca chuatsi).Four test diets were formulated to contain graded levels of B.subtilis 1-C-7 at 0(CY),0.85×10^(8)(Y1),0.95×10^(9)(Y2)and 0.91×10^(10)(Y3)CFU/kg diet.The test fish with initial weight 30.0±1.2 g were fed the 4 test diets with 3 replicates in an indoor water-flow aquaculture system with 12 net cages(40 fish/cage)for 10 wk.At the conclusion of the feeding trial,the probiotic effects of B.subtilis on Chinese perch were analyzed based on growth performance,serum biochemical indices,histologic morphology of liver and gut,gut microbiota and the resistance to Aero-monas hydrophila.The results showed that the percentage of weight gain had no significant change in the Y1 and Y2 groups(P>0.05)but decreased in the Y3 group compared to that in the CY group(P<0.05).The fish in the Y3 group displayed the highest activity of serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)among these 4 groups(P<0.05).The fish in the CY group had the highest value of malondialdehyde in the liver(P<0.05)and showed severe nuclear migration and vacuolization of hepatocytes.The morphology indicated that all test fish had poor intestinal health.However,the fish in the Y1 group had a relatively normal intestinal histologic structure.The mid gut microbial diversity analysis showed that dietary B.subtilis supplementation increased the abundance of probiotics such as Tenericutes and Bacteroides,whereas it reduced the abundance of pernicious bacteria such as Proteobacteria,Actinobacteria,Thermophilia and Spirochaetes.The challenge test showed that dietary B.subtilis supplementation increased the resistance to A.hydrophila in Chinese perch.In conclusion,dietary supplementation of 0.85×10^(8)CFU/kg B.subtilis 1-C-7 could improve the intestinal microbiota,intestinal health and disease resistance in Chinese perch,but more or excessive supple-mentation could reduce growth performance and have negative effects on health.
基金support from the National Natural Science Foundation of China(31872871 to QY and U2004207 to MG)the Fund for Distinguished Young Scholars in Henan(212300410007 to MG)+1 种基金the National Key Research and Development Program of China(2020YFA0907900 to QY)the Key Research and Development Program of Shaanxi(2021ZDLNY01-06 to QY)。
文摘In contrast to large-effect qualitative disease resistance,quantitative disease resistance(QDR)exhibits partial and generally durable resistance and has been extensively utilized in crop breeding.The molecular mechanisms underlying QDR remain largely unknown but considerable progress has been made in this area in recent years.In this review,we summarize the genes that have been associated with plant QDR and their biological functions.Many QDR genes belong to the canonical resistance gene categories with predicted functions in pathogen perception,signal transduction,phytohormone homeostasis,metabolite transport and biosynthesis,and epigenetic regulation.However,other"atypical"QDR genes are predicted to be involved in processes that are not commonly associated with disease resistance,such as vesicle trafficking,molecular chaperones,and others.This diversity of function for QDR genes contrasts with qualitative resistance,which is often based on the actions of nucleotidebinding leucine-rich repeat(NLR)resistance proteins.An understanding of the diversity of QDR mechanisms and of which mechanisms are effective against which classes of pathogens will enable the more effective deployment of QDR to produce more durably resistant,resilient crops.
基金supported by the National Key Research and Development Program of China(No.2021YFD2100505)the Project of Chongqing Science and Technology Bureau,China(cstc2021jscx-cylhX0015)the Project of Sichuan Science and Technology Plan,China(No.2021YFQ0071).
文摘As a famous fruit worldwide,citrus is susceptible to green mold caused by Penicillium digitatum,which causes large economic losses every year.e-Poly-L-lysine(e-PL)is a novel preservative with strong inhibitory effects on fungi,and has the capacity to induce disease resistance in fruit,but the mechanism has been reported rarely,especially in citrus.In the present study,8ooμg/mL e-PL and P digitatum spores were inoculated in two different wounds on the citrus pericarp at an interval of 24 h.The results revealed that e-PL inhibited that the development of green mold without direct contact with P digitatum,indicating that the disease resistance of citrus was activated.Transcriptome analysis revealed that e-PL activated amino acid metabolism and phenylpropanoid biosynthesis.Besides,the accumulation of glutamic acid,proline,arginine,serine,lysine,phenylalanine,and tyrosine were changed during storage.In phenylpropanoid biosynthesis,-PL increased phenylalanine ammonia-lyase(PAL),cinnamate 4-hydroxylase(C4H),and 4-coumarate:coenzyme A ligase(4CL)activities and total phenolic and flavonoid contents.Importantly.among these phenolic compounds,e-PL promoted the accumulation of individual phenolic compounds including ferulic acid,chlorogenic acid,p-coumaric acid,caffeic acid,gallic acid,catechins,epicatechin,and narirutin.In conclusion,e-PL enhanced the resistance of citrus through amino acid metabolism and accumulation of phenolic compounds.These results improved the knowledge of the mechanism of-PL-induced disease resistance and provided a fresh theoretical basis for the use of e-PL in postharvest citrus preservation.
基金Supported by National Natural Science Foundation of China (31760504)China Agriculture Research System of MOF and MARA(CARS-170303)+1 种基金Yunling Industry and Technology Leading Talent Training Program (2018LJRC56)Special Fund for the Construction of Modern Agricultural Industry Technology System in Yunnan Province。
文摘[Objectives]This study was conducted to establish simple, efficient, stable, standardized and practical identification methods for sugarcane resistance to white leaf disease(SCWL), and promote the breeding for sugarcane resistance to SCWL. [Methods]The identification technology of sugarcane resistance to SCWL was systematically studied and explored from the aspects of sugarcane material treatment and planting, inoculation liquid preparation, inoculation method, disease investigation, grading standard formulation, etc., and two sets of simple, efficient, stable, standardized and practical accurate identification methods for sugarcane resistance to SCWL were created for the first time, namely, the seed cane coating inoculation method and the stem-cutting inoculation method at the growth stage. The seed cane coating inoculation method includes the steps of directly screening SCWL phytoplasma, extracting juice from cane and adding 10 times of sterile water to prepare an inoculation liquid, spraying seed cane on plastic film to keep moisture, planting the inoculated materials in barrels in an insect-proof greenhouse for cultivation, investigating the incidence rate 30 d after inoculation, and evaluating the disease resistance according to the 1-5 level standard. The method of stem-cutting inoculation includes the steps of directly screening sugarcane stems carrying SCWL phytoplasma and adding 10 times of sterile water to prepare an inoculation liquid, cultivating the identification materials in an insect-proof greenhouse, dropping 100 μl of the inoculation liquid into each root incision with a pipette gun at the age of 6 months, investigating the incidence rate 20 d after planting, and evaluating the disease resistance according to the 1-5 level standard. [Results] The two methods are similar to the natural transmission method. After inoculation, SCML occurred significantly, with high sensitivity and good reproducibility. The results of resistance identification were consistent with those of natural disease in the field. Through the two inoculation methods and field natural disease investigation, the resistance of 10 main cultivars to SCML was identified, which was true and reliable. [Conclusions] This study can provide standard varieties for identification of SCML resistance in the future.
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supported by the National Key Research and Development Program of China(2022YFD2301100 and 2019YFD1000503)the Natural Science Foundation of Fujian Province(2021J01137)+1 种基金the Special Fund for Science and Technology Innovation of Fujian Agriculture and Forestry University(CXZX2020081A)the China Agriculture Research System(CARS-17).
文摘WRKY transcription factors,transcriptional regulators unique to plants,play an important role in defense response to pathogen infection.However,the resistance mechanisms of WRKY genes in sugarcane remain unclear.In the present study,gene ontology(GO)enrichment analysis revealed that WRKY gene family in sugarcane was extensively involved in the response to biotic stress and in defense response.We identified gene ScWRKY4,a classⅡc member of the WRKY gene family,in sugarcane cultivar ROC22.This gene was induced by salicylic acid(SA)and methyl jasmonate(MeJA)stress.Interestingly,expression of ScWRKY4 was down-regulated in smut-resistant sugarcane cultivars but up-regulated in smutsusceptible sugarcane cultivars infected with Sporisorium scitamineum.Moreover,stable overexpression of the ScWRKY4 gene in Nicotiana benthamiana enhanced susceptibility to Fusarium solani var.coeruleum and caused down-regulated expression of immune marker-related genes.Transcriptome analysis indicated suppressed expression of most JAZ genes in the signal transduction pathway.ScWRKY4 interacted with ScJAZ13 to repress its expression.We thus hypothesized that the ScWRKY4 gene was involved in the regulatory network of plant disease resistance,most likely through the JA signaling pathway.The present study depicting the molecular involvement of ScWRKY4 in sugarcane disease resistance lays a foundation for future investigation.
基金This work was supported by the National Key Research and Development Program of China(2016YFD0101002)the National Natural Science Foundation of China(31571676,32072007,and 31761143008)+4 种基金the Ministry of Science and Technology of the People's Republic of China(2015BAD02B01)the Fundamental Research Funds for the Central Universities(2014PY054 and 2662015PY185)the University Student Research Fund(2016090)the Innovation Training Plan of University Student Fund(201510504023)the Higher Education Discipline Innovation Project(B20051).
文摘Natural alleles controlling multiple disease resistances (MDR) are valuable for crop breeding. However, only one MDR gene have been cloned in maize, and molecular mechanisms of MDR are not clear. By map-based cloning, we have cloned a teosinte-derived allele of a resistance gene, Mexicana lesion mimic 1 (ZmMM1), which has a lesion mimic phenotype and confers resistance to northern leaf blight (NLB), gray leaf spot (GLS) and southern corn rust (SCR). Strong MDR conferred by the teosinte allele is linked with the polymorphisms in the 3' untranslated region of the ZmMM1 gene that cause increased accumulation of ZmMM1 protein. ZmMM1 acts as a transcription repressor and negatively regulates transcription of specific target genes including ZmMM1-target gene 3 (ZmMT3), which functions as a negative regulator of plant immunity and associated cell death. The successful isolation of the ZmMM1 resistance gene will help not only in developing broad-spectrum and durable disease resistance but also in understanding the molecular mechanisms underlying MDR.
