Verticillium wilt is one of the most serious constraints to cotton production in almost all of the cotton-growing countries. In this study, ＂XinLuZaol＂ （XLZl）, a susceptible cultivar Gossypium hirsutum L. and ＂Ha...Verticillium wilt is one of the most serious constraints to cotton production in almost all of the cotton-growing countries. In this study, ＂XinLuZaol＂ （XLZl）, a susceptible cultivar Gossypium hirsutum L. and ＂Hai7124＂ （H7124）, a resistant line G. barbadense, and their F2：3 families were used to map and study the disease index induced by verticillium wilt. A total of 430 SSR loci were mapped into 41 linkage groups; the map spanned 3 745.9 cM and the average distance between adjacent loci was 8.71 cM. Four and five quantitative trait loci （QTLs） were detected based on the disease index investigated on July 22 and August 24 in 2004, respectively. These nine QTLs explained 10.63-28.83% of the phenotypic variance, six of them were located on the D sub-genome. Two QTLs located in the same marker intervals may partly explain the significant correlation of the two traits. QTLs explaining large phenotypic variation were identified in this study, which may be quite useful in cotton anti-disease breeding.展开更多
Fungal pathogens represent a major group of plant invaders that are the causative agents of many notorious plant diseases. Large quantities of RNAs, especially small RNAs involved in gene silencing, have been found to...Fungal pathogens represent a major group of plant invaders that are the causative agents of many notorious plant diseases. Large quantities of RNAs, especially small RNAs involved in gene silencing, have been found to transmit bidirectionally between fungal pathogens and their hosts. Although host-induced gene silencing （HIGS） technology has been developed and applied to protect crops from fungal infections, the mechanisms of RNA transmission, especially small RNAs regulating trans- kingdom RNA silencing in plant immunity, are largely unknown. In this review, we summarize and discuss recent important findings regarding trans-kingdom sRNAs and RNA silencing in plant-fungal pathogen interactions compared with the well-known RNAi mechanisms in plants and fungi. We focus on the interactions between plant and fungal pathogens with broad hosts, represented by the vascular pathogen Verticillium dahliae and non-vascular pathogen Botrytis cinerea, and discuss the known instances of natural RNAi transmission between fungal pathogens and host plants. Given that HIGS has been developed and recently applied in controlling Verticillium wilt diseases, we propose an ideal research system exploiting plant vasculature-Verticillium interaction to further study trans-kingdom RNA silencing.展开更多
Verticillium wilt is a destructive disease with international consequences for cotton production. Breeding broad-spectrum resistant cultivars is considered to be one of the most effective means for reducing crop losse...Verticillium wilt is a destructive disease with international consequences for cotton production. Breeding broad-spectrum resistant cultivars is considered to be one of the most effective means for reducing crop losses. A resistant cotton cultivar,60182,was crossed with a susceptible cultivar,Jun-mian 1,to identify markers for Verticillium resistance genes and validate the mode of its inheritance. Genetic segregation analysis for Verticillium wilt resistance was evaluated based upon infected leaf percentage in the seedling stage using major gene-polygene mixed inheritance models and joint analysis of P1,P2,F1,B1,B2 and F2 populations obtained from the cultivar cross. We found that resistance of upland cotton cultivar 60182 to isolates BP2,VD8 and T9,and their isoconcentration mixture was controlled by two major genes with additive-dominance-epistatic effects,and the inheritance of the major gene was dominant. Furthermore,a genetic linkage map was constructed using F2 segregating population and resistance phenotypic data were obtained using F2:3 families inoculated with different isolates and detected in different developmental stages. The genetic linkage map with 139 loci was comprised of 31 linkage groups covering 1165 cM,with an average distance of 8.38 cM between two markers,or 25.89% of the cotton genome length. From 60182,we found 4 QTL on chromosome D7 and 4 QTL on D9 for BP2,5 QTL on D7 and 9 QTL on D9 for VD8,4 QTL on D7 and 5 QTL on D9 for T9 and 3 QTL on D7 and 7 QTL on D7 for mixed pathogens. The QTL mapping results revealed that QTL clusters with high contribution rates were screened simultaneously on chromosomes D9 and D7 by multiple interval mapping (CIM),whether from resistance phenotypic data from different developmental stages or for different isolates. The result is consistent with the genetic model of two major genes in 60182 and suggests broad-spectrum resistance to both defoliating isolates of V. dahliae and nondefoliating isolates. The markers associated with resistance QTL may facilitate th展开更多
This review summarizes the main advances in cotton breeding for resistance to fusarium and verticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences, problems and ...This review summarizes the main advances in cotton breeding for resistance to fusarium and verticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences, problems and countermeasures for solving.展开更多
Virus-induced gene silencing （VIGS） offers a powerful approach for functional analysis of individual genes by knocking down their expression. We have adopted this approach to dissect gene functions in cotton resista...Virus-induced gene silencing （VIGS） offers a powerful approach for functional analysis of individual genes by knocking down their expression. We have adopted this approach to dissect gene functions in cotton resistant to Verticfllium wilt, one of the most devastating diseases worldwide. We showed here that highly efficient VIGS was obtained in a cotton breeding line （CA4002） with partial resistance to Verticillium wilt, and GhMKK2 and Gh Ve I are required for its resistance to Verticillium wilt. Arabidopsis AtBAK1/SERK3, a central regulator in plant disease resistance, belongs to a subfamily of somatic embryogenesis receptor kinases （SERKs） with five members, AtSERK1 to AtSERK5. Two BAK1 orthologs and one SERK1 ortholog were identified in the cotton genome. Importantly, GhBAK1 is required for CA4002 resistance to Verticillium wilt. Surprisingly, silencing of GhBAK1 is sufficient to trigger cell death accompanied with production of reactive oxygen species in cotton. This result is distinct from Arabidopsis in which AtBAK1 and AtSERK4 play redundant functions in cell death control. Apparently, cotton has only evolved SERK1 and BAK1 whereas AtSERK4/5 are newly evolved genes in Arabidopsis. Our studies indicate the functional importance of BAK1 in Verticillium wilt resistance and suggest the dynamic evolution of SERK family members in different plant species.展开更多
Verticillium dahliae is a soil-borne phytopathogenic fungus that causes vascular wilt disease in a broad range of hosts. This pathogen survives for many years in soil in the form ofmelanized microsclerotia. To investi...Verticillium dahliae is a soil-borne phytopathogenic fungus that causes vascular wilt disease in a broad range of hosts. This pathogen survives for many years in soil in the form ofmelanized microsclerotia. To investigate the melanin synthesis in V.. dahliae, we identified a polyketide synthase gene in V. dahliae, namely VdPKS1. PKS1 is known to involve in the dihydroxynaphthalene melanin synthesis pathway in many fungi. We found that VdPKS1 was required for melanin formation but not for microsclerotial production in E dahliae. The VdPKS1 gene-disruption mutant （vdpksl） formed melanin-deficient albino microsclerotia, which did not affect the fungal colonization in host tissues but significantly reduced the disease severity. Gene transcription analysis in the wild-type and the vdpks1 strains suggested that VdPKS1 gene-disruption influenced the expression of a series of genes involved in ethylene biosynthesis, microsclerotial formation and pathogenesis. Our results suggest that the VdPKS1-mediated melanin synthesis is important for virulence and developmental traits of E dahliae.展开更多
[Objective]The aim of this study was to screen the antagonistic spore-forming bacteria of Verticillium dahliae and identify its physiological and biochemical characteristics.[Method]Taking the cotton verticillium wilt...[Objective]The aim of this study was to screen the antagonistic spore-forming bacteria of Verticillium dahliae and identify its physiological and biochemical characteristics.[Method]Taking the cotton verticillium wilt pathogen Verticillium dahliae V-190 as the test microorganism,the antagonistic spore-forming bacteria were screened.Through the preliminary screening and secondary screening,an antagonistic bacteria strain 7-30 with stronger antibacterial activity was obtained,and its morphological characteristics,physiological and biochemical characteristics were also identified.[Result]84 antagonistic bacteria strains were isolated from soil in various places by the preliminary screening.Especially,18 strains with better antagonistic ability were screened again,so an antagonistic bacteria strain 7-30 with the diameter of inhibition zone 18.9 mm and stronger antibacterial activity was obtained.According to its morphological characteristics,physiological and biochemical characteristics,the antagonistic bacteria strain 7-30 was identified as Bacillus subtilis primarily.[Conclusion]The strain 7-30 was obtained as the antagonistic spore-forming bacteria of Verticillium dahliae.展开更多
The different resistance of cotton (Gossypium hirsutum L.) cultivars to crude toxin of Verticillium dah/iae(VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of ...The different resistance of cotton (Gossypium hirsutum L.) cultivars to crude toxin of Verticillium dah/iae(VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of chitinase and β-1, 3-glucanase in the callus cells treated with the VD-toxin were increased to the higher level at earlier time point in resistant cultivars than these in the susceptible cultivars. Exogenous salicylic acid (SA) induced the accumulation of chitinase and β -1,3-glucanase, which resulted in the resistance of callus cells to the VD. toxin. Western blot using a polyclonal antibody against β -1,3-glucanase identified 28 kD protein that was induced by VD-toxin, SA, or VD-toxin plus SA.展开更多
Although there were reports suggesting the involvement of endogenous cAMP in plant defense signaling cascades, there is no direct evidence supporting this notion yet and the detailed mechanism is unclear. In the prese...Although there were reports suggesting the involvement of endogenous cAMP in plant defense signaling cascades, there is no direct evidence supporting this notion yet and the detailed mechanism is unclear. In the present study, we have used pathogenic fungi Verticillium dahliae and Arabidopsis plants as a model system of plant-microb interaction to demonstrate the function of endogenous cAMP in Arabidopsis defense responses. Both V. dahliae inoculation and Verticillium toxins injection induced typical “wilt” symptoms in Arabidopsis seedlings. When either 8-Br-AMP (a membrane permeable cAMP analogue) or salicylic acid (SA) was applied to Arabidopsis, the plants became resistant to V. dahliae toxins. However, addition of 8-Br-AMP did not increase the resistance of Arabidopsis transgenic plants deficient in SA to the toxins, suggesting that cAMP might act upstream of SA in plant defense signaling pathway. Indeed, 8-Br-cAMP and forskolin, an activator of adenylyl cyclase, significantly stimulated the endogenous SA level in plants, whereas DDA, an inhibitor of adenylyl cyclase dramatically reduced toxin-induced SA increase. Both the endog- enous cAMP and SA increased significantly in Arabidopsis seedlings treated with toxins. Furthermore, transcription level of pathogenesis-related protein 1 gene (PR1) was strongly induced by both 8-Br-cAMP and the toxin treatment. Taken together, our data demonstrate that endogenous cAMP is involved in plant defense responses against Verticillium- secreted toxins by regulating the production of the known signal SA in plant defense pathway.展开更多
Cotton Verticillium wilt is a serious soil-borne disease that leads to significant losses in fiber yield and quality worldwide. Currently, the most effective way to increase Verticillium wilt resistance is to develop ...Cotton Verticillium wilt is a serious soil-borne disease that leads to significant losses in fiber yield and quality worldwide. Currently, the most effective way to increase Verticillium wilt resistance is to develop new resistant cotton varieties. Lines 5026 and 60182 are two Verticillium wilt-resistant upland cotton accessions. We previously identified a total of 25 quantitative trait loci（QTLs） related to Verticillium wilt resistance from 5026 and 60182 by assembling segregating populations from hybridization with susceptible parents. In the current study, using 13 microsatellite markers flanking QTLs related to Verticillium wilt resistance, we developed 155 cotton inbred lines by pyramiding different QTLs related to Verticillium wilt resistance from a filial generation produced by crossing 5026 and 60182. By examining each allele＇s effect and performing multiple comparison analysis, we detected four elite QTLs/alleles（q-5/NAU905-2, q-6/NAU2754-2, q-8/NAU3053-1 and q-13/NAU6598-1） significant for Verticillium wilt resistance, pyramiding these elite alleles increased the disease resistance of inbred lines. Furthermore, we selected 34 elite inbred lines, including five lines simultaneously performing elite fiber quality, high yield and resistance to V. dahliae, 14 lines with elite fiber quality and disease resistance, three lines with high yield and disease resistance, and 12 lines with resistance to V. dahliae. No correlation between Verticillium wilt resistance and fiber quality traits/yield and its components was detected in the 155 developed inbred lines. Our results provide candidate markers for disease resistance for use in marker-assisted breeding（MAS）, as well as elite germplasms for improving important agronomic traits via modern cotton breeding.展开更多
We developed one species-specific PCR assays for rapid and accurate detection of the pathogenic fungi Verticillium albo-atrum in diseased plant tissues and soil. Based on differences in internal transcribed spacer （...We developed one species-specific PCR assays for rapid and accurate detection of the pathogenic fungi Verticillium albo-atrum in diseased plant tissues and soil. Based on differences in internal transcribed spacer （ITS） sequences of Verticillium spp., a pair of species-specific primers, Vaal/Vaa2, was synthesized. After screening 17 isolates of V. alboatrum, 121 isolates from the Ascomycota, B asidiomycota, Deuteromycota, and Oomycota, the Vaal/Vaa2 primers amplified only a single PCR band of approximately 330 bp from V. albo-atrum. The detection sensitivity with primers Vaal/Vaa2 was 10 fg of genomic DNA. Using ITS1/ITS4 as the first-round primers, combined with Vaa1/Vaa2, the nested PCR procedures were developed, and the detection sensitivity increased 1 000-fold to 10 ag. The detection sensitivity for the soil pathogens was 100-conidiag^-1 soil. The PCR-based methods developed here could simplify both plant disease diagnosis and pathogen monitoring as well as guide plant disease management.展开更多
This study was to explore the influence of the Verticillium dahliae Kleb inflection on the anti-enzyme inside the body of the cotton with a different root injured degree. When the cotton seedling was long, with four l...This study was to explore the influence of the Verticillium dahliae Kleb inflection on the anti-enzyme inside the body of the cotton with a different root injured degree. When the cotton seedling was long, with four leaves, it was flushed with water carefully, and then the following were obtained： （1） complete root seedling; （2） cut root seedling - by cutting off the lower part, 3-5 cm of the root, with a disinfected knife; （3） injured root seedling - by cutting off most of the side roots, but keeping the main root. Three kinds of cotton seedlings with different roots were immersed separately in different concentrations of the germ liquid （V. dahliae） of 20 mL each. Through 0- 48 h, the wilt degree of the seedling was recorded, and the related anti-enzyme of the variety was measured. After being immersed in the germ liquid, there was a significant difference in the wilt degree of the three kinds of injured root. When the germ liquid was in the ratio of 1：10, the complete root seedling was the lightest with no wilt; the injured root seedling was the second with a 2-degree wilt; but the cut root seedling was the most serious with a 3- degree wilt. At the same time, the changes in the peroxidase and malondialdehvde activities were determined. Peroxidase （POD） activities in the cut root seedling were 38.2 U mg^-1 min^-1, in the injured root seedling were 42.96 U mg^-1 min^-1, and in the complete root seedling were the highest at 49.2 U mg^-1 min^-1. The malondialdenvde （MDA） content in cut root seedling was 39.483 mmol g^-1, injured root seedling was 27.12 mmol g^-1, and the complete root seedling was only 3.845 mmol g^-1 The activity of the related anti-enzymes, such as POD was high or low, the quantity of the MDA was more or less, which they met the order of the harm of the seedlings. The change of SOD activities in cut root seedling was the most obvious as well. After injuring and inflecting the young roots, the exterior pathological reaction of the seedling and the dynamic state bioche展开更多
Development of pathogen-resistant crops, such as fungus-resistant cotton, has significantly reduced chemical application and improved crop yield and quality. However, the mechanism of resistance to cotton pathogens su...Development of pathogen-resistant crops, such as fungus-resistant cotton, has significantly reduced chemical application and improved crop yield and quality. However, the mechanism of resistance to cotton pathogens such as Verticillium dahliae is still poorly understood. In this study, we characterized a cotton gene （HDTF1） that was isolated following transcriptome profiling during the resistance response of cotton to V. dahliae. HDTFI putatively encodes a homeodomain transcription factor, and its expression was found to be down-regulated in cotton upon inoculation with V. dahliae and Botrytis cinerea. To characterise the involvement of HDTF1 in the response to these pathogens, we used virusinduced gene silencing （VlGS） to generate HDTFl-silenced cotton. VIGS reduction in HDTF1 expression significantly enhanced cotton plant resistance to both pathogens. HDTF1 silencing resulted in activation of jasmonic acid （JA）-mediated signaling and JA accumulation. However, the silenced plants were not altered in the accumulation of salicylic acid （SA） or the expression of marker genes associated with SA signaling. These results suggest that HDTF1 is a negative regulator of the JA pathway, and resistance to V. dahliae and B. cinerea can be engineered by activation of JA signaling.展开更多
The genus Mentha encompasses mint species cultivated for their essential oils, which are formulated into a vast array of consumer products. Desirable oil characteristics and resistance to the fungal disease Verti- cil...The genus Mentha encompasses mint species cultivated for their essential oils, which are formulated into a vast array of consumer products. Desirable oil characteristics and resistance to the fungal disease Verti- cillium wilt are top priorities for the mint industry. However, cultivated mints have complex polyploid ge- homes and are sterile. Breeding efforts, therefore, require the development of genomic resources for fertile mint species. Here, we present draft de novo genome and plastome assemblies for a wilt-resistant South African accession of Mentha Iongifolia （L.） Huds., a diploid species ancestral to cultivated peppermint and spearmint. The 353 Mb genome contains 35 597 predicted protein-coding genes, including 292 disease resistance gene homologs, and nine genes determining essential oil characteristics. A genetic linkage map ordered 1397 genome scaffolds on 12 pseudochromosomes. More than two million simple sequence repeats were identified, which will facilitate molecular marker development. The M. Iongifolia genome is a valuable resource for both metabolic engineering and molecular breeding. This is exemplified by employing the genome sequence to clone and functionally characterize the promoters in a peppermint cultivar, and demonstrating the utility of a glandular trichome-specific promoter to increase expression of a biosynthetic gene, thereby modulating essential oil composition.展开更多
WRKY transcription factors (TFs) play important roles in the regulation of biotic and abiotic stresses. However, the functions of most WRKY TFs in upland cotton (Gossypium hirsutum) are still unknown. In this study, w...WRKY transcription factors (TFs) play important roles in the regulation of biotic and abiotic stresses. However, the functions of most WRKY TFs in upland cotton (Gossypium hirsutum) are still unknown. In this study, we functionally identified a group Ⅲ WRKY transcription factor, GhWRKY70, in upland cotton. Reverse transcription-quantitative PCR analysis showed that GhWRKY70 expression was induced by Verticillium dahliae, salicylic acid (SA) and methyl jasmonate. Virus-induced gene silencing of GhWRKY70 increased the resistance of cotton to V. dahliae. Specifically, jasmonic acid (JA) response-associated genes were upregulated and SA-related genes were downregulated in GhWRKY70-silenced cotton plants. Overexpression of GhWRKY70 reduced tolerance to V. dahliae in Arabidopsis thaliana. Transgenic Arabidopsis plants showed increased expression of SA-associated genes and reduced expression of JA response-associated genes. These results suggest that GhWRKY70 negatively regulates tolerance to V. dahliae in at least two ways: (ⅰ) by upregulating the expression of SA-associated genes and (ⅱ) by reducing the expression of JA-associated genes.展开更多
基金the Communal Program Specially for Agricultural Research(nyhyz07-0528).
文摘Verticillium wilt is one of the most serious constraints to cotton production in almost all of the cotton-growing countries. In this study, ＂XinLuZaol＂ （XLZl）, a susceptible cultivar Gossypium hirsutum L. and ＂Hai7124＂ （H7124）, a resistant line G. barbadense, and their F2：3 families were used to map and study the disease index induced by verticillium wilt. A total of 430 SSR loci were mapped into 41 linkage groups; the map spanned 3 745.9 cM and the average distance between adjacent loci was 8.71 cM. Four and five quantitative trait loci （QTLs） were detected based on the disease index investigated on July 22 and August 24 in 2004, respectively. These nine QTLs explained 10.63-28.83% of the phenotypic variance, six of them were located on the D sub-genome. Two QTLs located in the same marker intervals may partly explain the significant correlation of the two traits. QTLs explaining large phenotypic variation were identified in this study, which may be quite useful in cotton anti-disease breeding.
基金This study was financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences （XDB11040500 to H.-S.G.）, National Natural Science Foundation （31730078 to H.-S.G., 31600124 to J.-H.Z., and 31500119 to C.H.）.
文摘Fungal pathogens represent a major group of plant invaders that are the causative agents of many notorious plant diseases. Large quantities of RNAs, especially small RNAs involved in gene silencing, have been found to transmit bidirectionally between fungal pathogens and their hosts. Although host-induced gene silencing （HIGS） technology has been developed and applied to protect crops from fungal infections, the mechanisms of RNA transmission, especially small RNAs regulating trans- kingdom RNA silencing in plant immunity, are largely unknown. In this review, we summarize and discuss recent important findings regarding trans-kingdom sRNAs and RNA silencing in plant-fungal pathogen interactions compared with the well-known RNAi mechanisms in plants and fungi. We focus on the interactions between plant and fungal pathogens with broad hosts, represented by the vascular pathogen Verticillium dahliae and non-vascular pathogen Botrytis cinerea, and discuss the known instances of natural RNAi transmission between fungal pathogens and host plants. Given that HIGS has been developed and recently applied in controlling Verticillium wilt diseases, we propose an ideal research system exploiting plant vasculature-Verticillium interaction to further study trans-kingdom RNA silencing.
基金Supported in part by the National Key Basic Research and Development Program of China (Grant No. 2006CB101708)the Communal Program Specially for Agricul-tural Research (Grant no. 3-19)+2 种基金the National Natural Science Foundation of China (Grant Nos. 30370899 and 30270806)the Jiangsu Natural Science Foundation, China (Grant No. BK2007719)the Program for 111 Project of the Ministry of Education, China (Grant No. B08025)
文摘Verticillium wilt is a destructive disease with international consequences for cotton production. Breeding broad-spectrum resistant cultivars is considered to be one of the most effective means for reducing crop losses. A resistant cotton cultivar,60182,was crossed with a susceptible cultivar,Jun-mian 1,to identify markers for Verticillium resistance genes and validate the mode of its inheritance. Genetic segregation analysis for Verticillium wilt resistance was evaluated based upon infected leaf percentage in the seedling stage using major gene-polygene mixed inheritance models and joint analysis of P1,P2,F1,B1,B2 and F2 populations obtained from the cultivar cross. We found that resistance of upland cotton cultivar 60182 to isolates BP2,VD8 and T9,and their isoconcentration mixture was controlled by two major genes with additive-dominance-epistatic effects,and the inheritance of the major gene was dominant. Furthermore,a genetic linkage map was constructed using F2 segregating population and resistance phenotypic data were obtained using F2:3 families inoculated with different isolates and detected in different developmental stages. The genetic linkage map with 139 loci was comprised of 31 linkage groups covering 1165 cM,with an average distance of 8.38 cM between two markers,or 25.89% of the cotton genome length. From 60182,we found 4 QTL on chromosome D7 and 4 QTL on D9 for BP2,5 QTL on D7 and 9 QTL on D9 for VD8,4 QTL on D7 and 5 QTL on D9 for T9 and 3 QTL on D7 and 7 QTL on D7 for mixed pathogens. The QTL mapping results revealed that QTL clusters with high contribution rates were screened simultaneously on chromosomes D9 and D7 by multiple interval mapping (CIM),whether from resistance phenotypic data from different developmental stages or for different isolates. The result is consistent with the genetic model of two major genes in 60182 and suggests broad-spectrum resistance to both defoliating isolates of V. dahliae and nondefoliating isolates. The markers associated with resistance QTL may facilitate th
文摘This review summarizes the main advances in cotton breeding for resistance to fusarium and verticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences, problems and countermeasures for solving.
基金supported by funds from the Texas AgriLife Research Cotton Improvement Program to J.D.,T.W.,P.H., and L.S.the USDA National Institute of Food and Agriculture(Agriculture and Food Research Initiative Competitive Grants Program grant no.2012-67013-19433) to P.H.+1 种基金L.S.A.K.was supported by the NSF REU programF.L.was supported by the China Scholarship Council
文摘Virus-induced gene silencing （VIGS） offers a powerful approach for functional analysis of individual genes by knocking down their expression. We have adopted this approach to dissect gene functions in cotton resistant to Verticfllium wilt, one of the most devastating diseases worldwide. We showed here that highly efficient VIGS was obtained in a cotton breeding line （CA4002） with partial resistance to Verticillium wilt, and GhMKK2 and Gh Ve I are required for its resistance to Verticillium wilt. Arabidopsis AtBAK1/SERK3, a central regulator in plant disease resistance, belongs to a subfamily of somatic embryogenesis receptor kinases （SERKs） with five members, AtSERK1 to AtSERK5. Two BAK1 orthologs and one SERK1 ortholog were identified in the cotton genome. Importantly, GhBAK1 is required for CA4002 resistance to Verticillium wilt. Surprisingly, silencing of GhBAK1 is sufficient to trigger cell death accompanied with production of reactive oxygen species in cotton. This result is distinct from Arabidopsis in which AtBAK1 and AtSERK4 play redundant functions in cell death control. Apparently, cotton has only evolved SERK1 and BAK1 whereas AtSERK4/5 are newly evolved genes in Arabidopsis. Our studies indicate the functional importance of BAK1 in Verticillium wilt resistance and suggest the dynamic evolution of SERK family members in different plant species.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB11040500)the National Natural Science Foundation of China(31160351,311060350)Basic Research Projects of Xingjiang Production and Construction Corps(2016AG001)
文摘Verticillium dahliae is a soil-borne phytopathogenic fungus that causes vascular wilt disease in a broad range of hosts. This pathogen survives for many years in soil in the form ofmelanized microsclerotia. To investigate the melanin synthesis in V.. dahliae, we identified a polyketide synthase gene in V. dahliae, namely VdPKS1. PKS1 is known to involve in the dihydroxynaphthalene melanin synthesis pathway in many fungi. We found that VdPKS1 was required for melanin formation but not for microsclerotial production in E dahliae. The VdPKS1 gene-disruption mutant （vdpksl） formed melanin-deficient albino microsclerotia, which did not affect the fungal colonization in host tissues but significantly reduced the disease severity. Gene transcription analysis in the wild-type and the vdpks1 strains suggested that VdPKS1 gene-disruption influenced the expression of a series of genes involved in ethylene biosynthesis, microsclerotial formation and pathogenesis. Our results suggest that the VdPKS1-mediated melanin synthesis is important for virulence and developmental traits of E dahliae.
基金Supported by National Science Foundation of Hebei Province(398152)~~
文摘[Objective]The aim of this study was to screen the antagonistic spore-forming bacteria of Verticillium dahliae and identify its physiological and biochemical characteristics.[Method]Taking the cotton verticillium wilt pathogen Verticillium dahliae V-190 as the test microorganism,the antagonistic spore-forming bacteria were screened.Through the preliminary screening and secondary screening,an antagonistic bacteria strain 7-30 with stronger antibacterial activity was obtained,and its morphological characteristics,physiological and biochemical characteristics were also identified.[Result]84 antagonistic bacteria strains were isolated from soil in various places by the preliminary screening.Especially,18 strains with better antagonistic ability were screened again,so an antagonistic bacteria strain 7-30 with the diameter of inhibition zone 18.9 mm and stronger antibacterial activity was obtained.According to its morphological characteristics,physiological and biochemical characteristics,the antagonistic bacteria strain 7-30 was identified as Bacillus subtilis primarily.[Conclusion]The strain 7-30 was obtained as the antagonistic spore-forming bacteria of Verticillium dahliae.
文摘The different resistance of cotton (Gossypium hirsutum L.) cultivars to crude toxin of Verticillium dah/iae(VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of chitinase and β-1, 3-glucanase in the callus cells treated with the VD-toxin were increased to the higher level at earlier time point in resistant cultivars than these in the susceptible cultivars. Exogenous salicylic acid (SA) induced the accumulation of chitinase and β -1,3-glucanase, which resulted in the resistance of callus cells to the VD. toxin. Western blot using a polyclonal antibody against β -1,3-glucanase identified 28 kD protein that was induced by VD-toxin, SA, or VD-toxin plus SA.
基金supported by the National Science Foundation of China(Grant No.39930010)a NSFC Fund for Creative Research Groups(Grant No.30421002)to Wei Hua WU
文摘Although there were reports suggesting the involvement of endogenous cAMP in plant defense signaling cascades, there is no direct evidence supporting this notion yet and the detailed mechanism is unclear. In the present study, we have used pathogenic fungi Verticillium dahliae and Arabidopsis plants as a model system of plant-microb interaction to demonstrate the function of endogenous cAMP in Arabidopsis defense responses. Both V. dahliae inoculation and Verticillium toxins injection induced typical “wilt” symptoms in Arabidopsis seedlings. When either 8-Br-AMP (a membrane permeable cAMP analogue) or salicylic acid (SA) was applied to Arabidopsis, the plants became resistant to V. dahliae toxins. However, addition of 8-Br-AMP did not increase the resistance of Arabidopsis transgenic plants deficient in SA to the toxins, suggesting that cAMP might act upstream of SA in plant defense signaling pathway. Indeed, 8-Br-cAMP and forskolin, an activator of adenylyl cyclase, significantly stimulated the endogenous SA level in plants, whereas DDA, an inhibitor of adenylyl cyclase dramatically reduced toxin-induced SA increase. Both the endog- enous cAMP and SA increased significantly in Arabidopsis seedlings treated with toxins. Furthermore, transcription level of pathogenesis-related protein 1 gene (PR1) was strongly induced by both 8-Br-cAMP and the toxin treatment. Taken together, our data demonstrate that endogenous cAMP is involved in plant defense responses against Verticillium- secreted toxins by regulating the production of the known signal SA in plant defense pathway.
基金financially supported in part by the National Natural Science Foundation of China (31171590)the National High-Tech R&D Program of China (863 Program, 2012AA101108)+2 种基金the Jiangsu Agriculture Science and Technology Innovation Fund, China (cx(13)3059)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (010-809001)the Jiangsu Collaborative Innovation Center for Modern Crop Production, China (No. 10)
文摘Cotton Verticillium wilt is a serious soil-borne disease that leads to significant losses in fiber yield and quality worldwide. Currently, the most effective way to increase Verticillium wilt resistance is to develop new resistant cotton varieties. Lines 5026 and 60182 are two Verticillium wilt-resistant upland cotton accessions. We previously identified a total of 25 quantitative trait loci（QTLs） related to Verticillium wilt resistance from 5026 and 60182 by assembling segregating populations from hybridization with susceptible parents. In the current study, using 13 microsatellite markers flanking QTLs related to Verticillium wilt resistance, we developed 155 cotton inbred lines by pyramiding different QTLs related to Verticillium wilt resistance from a filial generation produced by crossing 5026 and 60182. By examining each allele＇s effect and performing multiple comparison analysis, we detected four elite QTLs/alleles（q-5/NAU905-2, q-6/NAU2754-2, q-8/NAU3053-1 and q-13/NAU6598-1） significant for Verticillium wilt resistance, pyramiding these elite alleles increased the disease resistance of inbred lines. Furthermore, we selected 34 elite inbred lines, including five lines simultaneously performing elite fiber quality, high yield and resistance to V. dahliae, 14 lines with elite fiber quality and disease resistance, three lines with high yield and disease resistance, and 12 lines with resistance to V. dahliae. No correlation between Verticillium wilt resistance and fiber quality traits/yield and its components was detected in the 155 developed inbred lines. Our results provide candidate markers for disease resistance for use in marker-assisted breeding（MAS）, as well as elite germplasms for improving important agronomic traits via modern cotton breeding.
基金We thank Dr Chen Qinghe,Dr Ko Wenhong,Dr Ho Hanhin,Dr Hu Baishi,Dr Peng Jinghuo and China General Microbiological Culture Collection Center(CGMCC)for providing some isolates.This work was supported by the China National 863 Program(2003AA249020).
文摘We developed one species-specific PCR assays for rapid and accurate detection of the pathogenic fungi Verticillium albo-atrum in diseased plant tissues and soil. Based on differences in internal transcribed spacer （ITS） sequences of Verticillium spp., a pair of species-specific primers, Vaal/Vaa2, was synthesized. After screening 17 isolates of V. alboatrum, 121 isolates from the Ascomycota, B asidiomycota, Deuteromycota, and Oomycota, the Vaal/Vaa2 primers amplified only a single PCR band of approximately 330 bp from V. albo-atrum. The detection sensitivity with primers Vaal/Vaa2 was 10 fg of genomic DNA. Using ITS1/ITS4 as the first-round primers, combined with Vaa1/Vaa2, the nested PCR procedures were developed, and the detection sensitivity increased 1 000-fold to 10 ag. The detection sensitivity for the soil pathogens was 100-conidiag^-1 soil. The PCR-based methods developed here could simplify both plant disease diagnosis and pathogen monitoring as well as guide plant disease management.
基金Natural Science Foundation of Hebei Province,China(C2006000744)International Project of Science and Technology between South Africa and China's Mainland(2006DFB02480)+1 种基金National Key Project of Scientific and Technical Supporting Programs in the 11th Five-Year-Plan of Ministry of Science and Technology,China(2006BAD01A05-04)Key Technologies R&D Program of Hebei Province,China(06220113D).
文摘This study was to explore the influence of the Verticillium dahliae Kleb inflection on the anti-enzyme inside the body of the cotton with a different root injured degree. When the cotton seedling was long, with four leaves, it was flushed with water carefully, and then the following were obtained： （1） complete root seedling; （2） cut root seedling - by cutting off the lower part, 3-5 cm of the root, with a disinfected knife; （3） injured root seedling - by cutting off most of the side roots, but keeping the main root. Three kinds of cotton seedlings with different roots were immersed separately in different concentrations of the germ liquid （V. dahliae） of 20 mL each. Through 0- 48 h, the wilt degree of the seedling was recorded, and the related anti-enzyme of the variety was measured. After being immersed in the germ liquid, there was a significant difference in the wilt degree of the three kinds of injured root. When the germ liquid was in the ratio of 1：10, the complete root seedling was the lightest with no wilt; the injured root seedling was the second with a 2-degree wilt; but the cut root seedling was the most serious with a 3- degree wilt. At the same time, the changes in the peroxidase and malondialdehvde activities were determined. Peroxidase （POD） activities in the cut root seedling were 38.2 U mg^-1 min^-1, in the injured root seedling were 42.96 U mg^-1 min^-1, and in the complete root seedling were the highest at 49.2 U mg^-1 min^-1. The malondialdenvde （MDA） content in cut root seedling was 39.483 mmol g^-1, injured root seedling was 27.12 mmol g^-1, and the complete root seedling was only 3.845 mmol g^-1 The activity of the related anti-enzymes, such as POD was high or low, the quantity of the MDA was more or less, which they met the order of the harm of the seedlings. The change of SOD activities in cut root seedling was the most obvious as well. After injuring and inflecting the young roots, the exterior pathological reaction of the seedling and the dynamic state bioche
基金financially supported by the International Science&Technology Cooperation Program of China(No.2015DFA30860)a grant from Ministry of Agriculture of China(No.2014ZX0800503B)
文摘Development of pathogen-resistant crops, such as fungus-resistant cotton, has significantly reduced chemical application and improved crop yield and quality. However, the mechanism of resistance to cotton pathogens such as Verticillium dahliae is still poorly understood. In this study, we characterized a cotton gene （HDTF1） that was isolated following transcriptome profiling during the resistance response of cotton to V. dahliae. HDTFI putatively encodes a homeodomain transcription factor, and its expression was found to be down-regulated in cotton upon inoculation with V. dahliae and Botrytis cinerea. To characterise the involvement of HDTF1 in the response to these pathogens, we used virusinduced gene silencing （VlGS） to generate HDTFl-silenced cotton. VIGS reduction in HDTF1 expression significantly enhanced cotton plant resistance to both pathogens. HDTF1 silencing resulted in activation of jasmonic acid （JA）-mediated signaling and JA accumulation. However, the silenced plants were not altered in the accumulation of salicylic acid （SA） or the expression of marker genes associated with SA signaling. These results suggest that HDTF1 is a negative regulator of the JA pathway, and resistance to V. dahliae and B. cinerea can be engineered by activation of JA signaling.
文摘The genus Mentha encompasses mint species cultivated for their essential oils, which are formulated into a vast array of consumer products. Desirable oil characteristics and resistance to the fungal disease Verti- cillium wilt are top priorities for the mint industry. However, cultivated mints have complex polyploid ge- homes and are sterile. Breeding efforts, therefore, require the development of genomic resources for fertile mint species. Here, we present draft de novo genome and plastome assemblies for a wilt-resistant South African accession of Mentha Iongifolia （L.） Huds., a diploid species ancestral to cultivated peppermint and spearmint. The 353 Mb genome contains 35 597 predicted protein-coding genes, including 292 disease resistance gene homologs, and nine genes determining essential oil characteristics. A genetic linkage map ordered 1397 genome scaffolds on 12 pseudochromosomes. More than two million simple sequence repeats were identified, which will facilitate molecular marker development. The M. Iongifolia genome is a valuable resource for both metabolic engineering and molecular breeding. This is exemplified by employing the genome sequence to clone and functionally characterize the promoters in a peppermint cultivar, and demonstrating the utility of a glandular trichome-specific promoter to increase expression of a biosynthetic gene, thereby modulating essential oil composition.
基金supported by the National Key Research and Development Program of China (2016YFD0100200)Science and Technology Development Program of Xinjiang Production and Construction Groups (2015AC007)Crops Breeding Project of Shihezi University (YZZX201704)
文摘WRKY transcription factors (TFs) play important roles in the regulation of biotic and abiotic stresses. However, the functions of most WRKY TFs in upland cotton (Gossypium hirsutum) are still unknown. In this study, we functionally identified a group Ⅲ WRKY transcription factor, GhWRKY70, in upland cotton. Reverse transcription-quantitative PCR analysis showed that GhWRKY70 expression was induced by Verticillium dahliae, salicylic acid (SA) and methyl jasmonate. Virus-induced gene silencing of GhWRKY70 increased the resistance of cotton to V. dahliae. Specifically, jasmonic acid (JA) response-associated genes were upregulated and SA-related genes were downregulated in GhWRKY70-silenced cotton plants. Overexpression of GhWRKY70 reduced tolerance to V. dahliae in Arabidopsis thaliana. Transgenic Arabidopsis plants showed increased expression of SA-associated genes and reduced expression of JA response-associated genes. These results suggest that GhWRKY70 negatively regulates tolerance to V. dahliae in at least two ways: (ⅰ) by upregulating the expression of SA-associated genes and (ⅱ) by reducing the expression of JA-associated genes.
