scholarly journals Efficacy of resistance selection to Verticillium wilt in strawberry (Fragaria x ananassa Duch.) tissue culture

2012 ◽  
Vol 64 (3) ◽  
pp. 3-12 ◽  
Author(s):  
Jadwiga I. Żebrowska
Keyword(s):  
Tissue Culture ◽  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Pathogenic Fungus ◽  
Genetic Resistance ◽  
Fragaria X Ananassa ◽  
Post Inoculation ◽  
Disease Symptoms ◽  
Resistance Selection

The soil-borne pathogenic fungus <i>Verticillium dahliae</i> Kleb. causes economic losses in crops in temperate regions of the world and hence is the most studied species. Strawberry (<i>Fragaria x ananassa</i> Duch.) belongs to plant species susceptible to <i>Verticillium dahliae</i>, although the response to infection caused by this pathogen is varied and depends on the cultivar. Due to a lack of efficient methods in Verticillium wilt elimination, the selection of genetically resistant plant material is a priority direction in breeding programs. Efficacy of resistance selection to <i>Verticillium dahliae</i> Kleb. in strawberry tissue culture was examined on the basis of response to <i>in vitro</i> infection by this pathogenic fungus in two tissue cultured strawberry cultivars, i.e. 'Filon' and 'Teresa'. Culture was conducted for 16 months in an environmentally controlled growth room at 18-20°C, 60-70% relative humidity and light intensity of 100 µm E × m<sup>-2</sup> × s<sup>-1</sup> on a 16h light / 8h dark cycle. Subcultures were proliferated every 6 weeks on modified Murashige and Skoog medium. Four hundred microplants from each tissue cultured cultivar were inoculated under <i>in vitro</i> conditions at the 4-leaf stage with a homogenate of liquid mycelium of <i>Verticillium dahliae</i> serving as the selecting agent. Disease symptoms were observed at 15, 30, 45, 60, and 75th days post inoculation. The extent of leaf chlorosis was rated on a scale of 0-4. At day 75<sup>th</sup> post inoculation, the percentage of totally chlorotic plants in micropropagated cv. Teresa reached the value of 76.27%, whereas the proportion of such plants in inoculated tissue cultured cv. Filon reached the value of 89.40%. Also, the index of infection calculated for very severe disease symptoms in the subclone 'Teresa' reached the mean value lower when compared with that calculated for subclone 'Filon' (0.0962 and 0.1150, respectively). These results suggested that the micropropagated cv. Teresa exhibited higher genetic resistance to the selecting agent in comparison with the tissue cultured cv. Filon, and it was consistent with field resistance of both cultivars to this pathogen. Therefore, the procedure of <i>in vitro</i> selection used in this study was quite efficient to distinguish varying genetic resistance to <i>Verticillium dahliae</i> in the two examined strawberry subclones, and can be recommended as a suitable method for the estimation of susceptibility to Verticillium wilt in different strawberry genotypes.

scholarly journals Biocontrol potential of Trichoderma harzianum in controlling wilt disease of pistachio caused by Verticillium dahliae

2017 ◽  
Vol 57 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Zeinab Fotoohiyan ◽  
Saeed Rezaee ◽  
Gholam Hosein Shahidi Bonjar ◽  
Amir Hossein Mohammadi ◽  
Mohammad Moradi
Keyword(s):  
Verticillium Dahliae ◽  
Trichoderma Harzianum ◽  
Pathogenic Fungus ◽  
Antagonistic Activity ◽  
Wilt Disease ◽  
Dual Culture ◽  
Volatile Metabolites ◽  
Biocontrol Potential

Abstract Verticillium wilt caused by Verticillium dahliae, is one of the most devastating diseases in pistachio orchards in the world including Iran. In search for an effective non-chemical strategy for the management of this disease, we evaluated the biocontrol potential of Trichoderma harzianum isolates obtained from the rhizosphere of healthy pistachio trees in different locations of the Kerman province of Iran against V. dahliae under laboratory and greenhouse conditions. Dual culture tests in the laboratory were conducted in a completely randomized design using 72 T. harzianum isolates. Twenty isolates showed the highest in vitro antagonistic activity. The results indicated that all 20 isolates were capable of inhibiting the mycelial growth of V. dahliae significantly. Among them, isolates Tr8 and Tr19 were the most effective by 88.89% and 85.12% inhibition, respectively. Extracted cell free metabolites of all effective isolates also inhibited the growth of V. dahliae in the culture medium significantly. According to the results, isolates Tr4 and Tr6 inhibited fungal pathogen growth by 94.94% and 88.15% respectively, through production of non-volatile metabolites. In the evaluation of volatile metabolites, isolates Tr5 and Tr4 were the most effective by 26.27% and 24.49% growth inhibition, respectively. Based on the results of the in vitro experiments, the five most effective isolates were selected for evaluation under greenhouse conditions for their biocontrol potential in controlling Verticillium wilt of pistachio. Results of the greenhouse, (in vivo) experiments were positive and indicated that the occurrence of wilt disease in plants treated with the antagonists alone or in combination with pathogenic fungus was lower than in plants inoculated with pathogen alone. The overall results of this study suggest that Trichoderma fungal antagonist may be an effective biocontrol agent for the control of Verticillium wilt of pistachio.

scholarly journals Transcriptome analysis reveals the mechanism by which the biocontrol fungus Chaetomium globosum CEF-082 controls Verticillium wilt in cotton

2019 ◽  
Author(s):  
Yun Zhang ◽  
Na Yang ◽  
Lihong Zhao ◽  
Heqin Zhu ◽  
Canming Tang
Keyword(s):  
Molecular Mechanism ◽  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Substantial Reduction ◽  
Enrichment Analysis ◽  
Metabolic Process ◽  
Defence Response ◽  
Chaetomium Globosum ◽  
Post Inoculation ◽  
Mapk Signalling Pathway

Abstract Background: Verticillium wilt of cotton is a serious soil-borne disease that causes a substantial reduction in cotton yield. A previous study showed that the endophytic fungus Chaetomium globosum CEF-082 could control Verticillium wilt of cotton, but the molecular mechanism by which CEF-082 controls Verticillium wilt is still unknown. Results: To study the mechanism by which CEF-082 controls Verticillium wilt, the transcriptome of cotton seedlings pretreated with CEF-082 was sequenced. The results revealed 5638 DEGs 24 h post-inoculation with CEF-082, and 2921 and 2153 DEGs 12 and 48 h post-inoculation with Verticillium dahliae , respectively. At twenty-four hours post-inoculation with CEF-082, KEGG enrichment analysis indicated that the DEGs were mainly enriched in plant-pathogen interaction, MAPK signalling pathway-plant, flavonoid biosynthesis, and phenylpropanoid biosynthesis. There were 1209 DEGs specifically induced after inoculation with CEF-082 and V. dahliae . GO enrichment indicated that these DEGs were mainly enriched in the terms reactive oxygen species metabolic process, hydrogen peroxide metabolic process, defence response, superoxide dismutase activity, and antioxidant activity. Here, many genes, such as ERF, CNGC, FLS2, MYB, GST and CML, were identified that regulate crucial points in defence-related pathways and that may contribute to V. dahliae resistance in cotton. These results provide a basis for the understanding of the molecular mechanism by which biocontrol fungi control Verticillium wilt. Conclusions: In this study, we found that CEF-082 could regulate multiple metabolic pathways in cotton. After treatment with Verticillium dahliae , the defence response of cotton plants pre-inoculated with CEF-082 was strengthened.

scholarly journals Verticillium dahliae effector VDAL protects MYB6 from degradation by interacting with PUB25/26 E3 ligases for enhancing Verticillium wilt resistance in Arabidopsis

2021 ◽  
Author(s):  
Zhizhong Gong ◽  
Junsheng Qi ◽  
Aifang Ma ◽  
Dingpeng Zhang ◽  
Guangxing Wang ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Plant Resistance ◽  
Plant Disease Resistance ◽  
Plant Disease ◽  
Effector Proteins ◽  
In Planta ◽  
E3 Ligases

Verticillium wilt is a severe plant disease, increasing the plant resistance to this disease is a critical challenge worldwide. Here, we report that the Verticillium dahliae (V. dahliae)-secreted Aspf2-like protein VDAL causes leaf wilting when applied to cotton leaves in vitro, but enhances the resistance to V. dahliae when overexpressed in Arabidopsis or cotton. VDAL interacts with Arabidopsis E3 ligases PUB25 and PUB26 (PUBs) and is ubiquitinated by PUBs in vitro. However, VDAL is not degraded by PUBs in planta. Besides, the pub25 pub26 shows higher resistance to V. dahliae than the wild type. PUBs interact with the transcription factor MYB6 in a yeast two-hybrid screen. MYB6 promotes plant resistance to Verticillium wilt while PUBs ubiquitinate MYB6 and mediate its degradation. VDAL competes with MYB6 for binding to PUBs, and the role of VDAL in increasing wilt disease depends on MYB6. These results suggest that plants evolute a strategy to utilize the invaded effector protein VDAL to resist the V. dahliae infection without causing a hypersensitive response. This study provides the molecular mechanism for plants increasing disease resistance when overexpressing some effector proteins, and may promote searching for more genes from pathogenic fungi or bacteria to engineer plant disease resistance.

scholarly journals Deletion of Mid1, a putative stretch-activated calcium channel in Claviceps purpurea, affects vegetative growth, cell wall synthesis and virulence

Microbiology ◽  
2009 ◽  
Vol 155 (12) ◽  
pp. 3922-3933 ◽  
Author(s):  
Jörg Bormann ◽  
Paul Tudzynski
Keyword(s):  
Vegetative Growth ◽  
Pathogenic Fungus ◽  
Axenic Culture ◽  
Gene Replacement ◽  
Major Effect ◽  
Growth Defect ◽  
Claviceps Purpurea ◽  
Disease Symptoms

The putative Claviceps purpurea homologue of the Saccharomyces cerevisiae stretch-activated calcium ion channel Mid1 was investigated for its role in vegetative growth, differentiation and pathogenicity on rye (Secale cereale). Gene replacement mutants of Cl. purpurea mid1 were not affected in polar growth and branching in axenic culture but showed a significantly reduced growth rate. The growth defect could not be complemented by Ca2+ supplementation, in contrast to mid1 mutants in yeast, but the altered sensitivity of the mutants to changes in external and internal Ca2+ concentrations indicates some role of Mid1 in Ca2+ homeostasis. The major effect of mid1 deletion, however, was the complete loss of virulence: infected rye plants showed no disease symptoms at all. Detailed analyses of in vitro-infected rye ovaries demonstrated that the Δmid1 mutants had multiple apical branches and were unable to infect the host tissue, suggesting that Mid1 is essential for generating the necessary mechanical force for penetration. This is believed to be the first report of an essential role for a Mid1 homologue in the virulence of a plant-pathogenic fungus.

scholarly journals First Report of Verticillium Wilt of Watermelon Caused by Verticillium dahliae in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Xiuyun Lu ◽  
Junyan Shang ◽  
Luxin Niu ◽  
Xiangrui Sun ◽  
Zhenhe Su ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Its Region ◽  
Sequence Information ◽  
Post Inoculation ◽  
Continuous Cropping ◽  
Conidial Suspension ◽  
First Report ◽  
Fungal Isolates ◽  
Pathogenicity Tests

Watermelon (Citrullus lanatus T.) is one of the most important economic crops in China. Soil-borne diseases are becoming more and more serious with longer growing seasons and continuous cropping of watermelon in greenhouses. In May 2020, symptoms were observed on plants in greenhouses located at Xingtai, Hebei province of China and included wilted leaves, chlorosis and plant death. Among the 26 greenhouses examined, symptomatic plants were observed in 17 greenhouses. The incidences of infected plants ranged from 1% to 35%, and caused an average 10% yield loss. Symptoms began on lower part of the plants and progressed upward to the vines and leaves. At the early stage of infection, the edge of watermelon leaves changed from green to yellow, and became soft. As the disease progressed, infected leaves wilted and desicated. The vascular tissue of the stem exhibited a uniform brown discoloration that often extended throughout the vine. To identify the causal agent, small pieces approximate 3.0×3.0 mm size of infected stem tissues were collected and sterilized with 0.5% sodium hypochlorite solution for 1 min, rinsed three times with sterile water and transferred onto potato dextrose agar (PDA) medium amended with 100 μg·mL-1 of chloramphenicol. The plates were incubated at 25°C for 3 days in the dark and fungal isolates were purified using the single-spore isolation method. A total of 22 fungal isolates with identical colony morphology were collected from diseased plants. The color of the fungal colonies on PDA medium was creamy-white with an abundance of mycelia that darken after 5 days growth due to the formation of microsclerotia. Fungal colonies consisted of fine, hyaline hyphae with verticillate conidiophores producing hyaline, ellipsoidal to oval conidia with an average size of 5.12×3.41 μm (n=50). The morphological characters of the fungal isolates were identical to those of Verticillium dahliae Kleb. described by Hawksworth and Talboys (Hawksworth, D. and Talboys, P, 1970). Pathogenicity tests were performed by soaking 30 watermelon seedlings with wounded root tips in the fungal conidial suspension (1x107 conidium/mL) for 30 min (Ma, et al, 2004). The same number of non-inoculated watermelon seedlings was used as a control. All plants were kept in a greenhouse at 25°C and 90%-95% relative humidity. Seven days post-inoculation (dpi), leaves of treated plants began to show symptoms of wilt. At 10-dpi, lower leaves wilted and dry and by 15-dpi, whole plants were dead. Pathogenicity tests were repeated three times with consistent results. The pathogen was re-isolated from the diseased plants and displayed identical morphological characteristics to the original isolates. To further identity the pathogens, the ribosomal DNA Internal Transcribed Spacer (rDNA-ITS) region was amplified by PCR (White et al., 1990; Liu et al., 1999; Bellemain et al.. 2010). The amplicon was sequenced and showed 99%-100% identity to the ITS region of the V. dahliae reference strains deposited in the NCBI database (MK093977.1, MK287620.1, MT348570.1 and LC549667.1, respectively). Based on morphological and ITS sequence information, the fungal pathogen was identified as V. dahliae. V. dahliae is an economically important pathogen with a wide host range worldwide. The discovery of Verticillium wilt on watermelons indicates that there might be a risk of Verticillium wilt when watermelons are planted in subsequent crops of the host plants of the disease, such as cotton or eggplant. To our knowledge, this is the first report of V. dahliae causing Verticillium wilt of watermelon in China. Financed: the Special Fund for Agro-scientific Research in the Public Interest, China (201503109) References: Hawksworth, D. and Talboys, P. 1970. Description of Pathogenic Fungi and Bacteria, CMI, Surrey. Ma, P., et al. 2004. A New Inoculation Method for Verticillium Wilt on Cotton and Its Application in Evaluating Pathogenesis and Host Resistance. Acta Phytopathologica Sinica, 34(6): 536-541. White, T. J., et al. 1990. Amplification and Direct Sequencing of Fungal Ribosomal RNA Genes for Phylogenetics. PCR protocols: a guide to methods and applications, 18(1), 315-322. Bellemain, E., et al. 2010. ITS as an Environmental DNA Barcode for Fungi: an in Silico Approach Reveals Potential PCR Biases. BMC microbiology, 10(1), 1-9. Liu, Y. J., et al. 1999. Phylogenetic Relationships Among Ascomycetes: Evidence from an RNA Polymerse II SubunitMol. Biol. Evol. 16:1799-1808.

scholarly journals Reaction of Broccoli to Isolates of Verticillium dahliae from Various Hosts

Plant Disease ◽  
2001 ◽  
Vol 85 (2) ◽  
pp. 141-146 ◽  
Author(s):  
R. G. Bhat ◽  
K. V. Subbarao
Keyword(s):  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Cropping Systems ◽  
Severe Disease ◽  
Disease Symptoms ◽  
Inoculation Method ◽  
Vascular Discoloration ◽  
Root Tissues ◽  
Rotation Crop

Isolates of Verticillium dahliae from 15 different hosts and V. albo-atrum from alfalfa were tested for their ability to cause wilt on broccoli using a root-dip inoculation method. None of the isolates caused vascular discoloration in broccoli except those from cabbage and cauliflower that were weakly pathogenic. Broccoli cultivars Baccus, Greenbelt, Parasol, Patriot, and Symphony showed resistance to Verticillium infection. Re-isolated strains from fresh samples of internally discolored broccoli and cauliflower root tissues were unable to cause disease symptoms on re-inoculation of broccoli, but caused severe disease on cauliflower. Inoculation of 5-, 7-, 9-, or 11-week-old plants did not alter the resistance in broccoli or the susceptibility in cauliflower against Verticillium. Immunity of broccoli against infection by isolates of V. dahliae from non-crucifer hosts, its resistance against crucifer isolates, and as previously described, attrition of V. dahliae microsclerotia in soil by broccoli residue, coupled with its importance as a commercial vegetable, make broccoli an attractive rotation crop for the management of Verticillium wilt in many cropping systems.

scholarly journals Down regulation of cotton GbTRP1 leads to accumulation of anthranilates and confers resistance to Verticillium dahliae

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Yuhuan MIAO ◽  
Longfu ZHU ◽  
Xianlong ZHANG
Keyword(s):  
Immune Response ◽  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Cellular Localization ◽  
Resistance Breeding ◽  
Cancer Disease ◽  
Resistant Varieties ◽  
Broad Spectrum Resistance ◽  
Disease Resistance Breeding

Abstract Background Verticillium wilt, caused by Verticillium dahliae, is called a “cancer” disease of cotton. The discovery and identification of defense-related genes is essential for the breeding of Verticillium wilt-resistant varieties. In previous research we identified some possible broad-spectrum resistance genes. Here, we report a tryptophan synthesis-related gene GbTRP1 and its functional analysis in relation to the resistance of cotton to V. dahliae. Results Expression analysis shows that GbTRP1 is suppressed at 1 h and 6 h post V. dahliae infection, but activated at 12 h and 24 h, and the expression of GbTRP1 is highly induced by treatment with salicylic acid and jasmonic acid. Sub-cellular localization studies show that GbTRP1 is localized in the chloroplast. Suppression of GbTRP1 expression leads to lesion-mimic phenotypes and activates the immune response in cotton by showing enhanced resistance to V. dahliae and B. cinerea. Metabolomic analysis shows that anthranilic compounds significantly accumulated in GbTRP1-silenced plants, and these metabolites can inhibit the growth of V. dahliae and B. cinerea in vitro. Conclusions Our results show that suppression of GbTRP1 expression dramatically activates the immune response and increases resistance of cotton to V. dahliae and B. cinerea, possibly due to the accumulation of anthranilate compounds. This study not only provides genetic resources for disease resistance breeding, but also may provide a basis for new chemical control methods for combatting of fungal disease in cotton.

scholarly journals Transcriptome analysis reveals the defense mechanism of cotton against Verticillium dahliae in the presence of the biocontrol fungus Chaetomium globosum CEF-082

2019 ◽  
Author(s):  
YUN ZHANG ◽  
Na Yang ◽  
Lihong Zhao ◽  
Heqin Zhu ◽  
Canming Tang(New Corresponding Author)
Keyword(s):  
Molecular Mechanism ◽  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Defense Response ◽  
Defense Mechanism ◽  
Substantial Reduction ◽  
Metabolic Process ◽  
Chaetomium Globosum ◽  
Post Inoculation ◽  
Cotton Plants

Abstract Background: Verticillium wilt of cotton is a serious soil-borne disease that causes a substantial reduction in cotton yields. A previous study showed that the endophytic fungus Chaetomium globosum CEF-082 could control Verticillium wilt of cotton, and induce a defense response in cotton plants. However, the comprehensive molecular mechanism governing this response is not yet clear. Results: To study the signalling mechanism induced by CEF-082, the transcriptome of cotton seedlings pretreated with CEF-082 was sequenced. The results revealed 5638 DEGs at 24 h post inoculation with CEF-082, and 2921 and 2153 DEGs at 12 and 48 h post inoculation with Verticillium dahliae, respectively. At 24 h post inoculation with CEF-082, KEGG enrichment analysis indicated that the DEGs were enriched mainly in the plant-pathogen interaction, MAPK signalling pathway-plant, flavonoid biosynthesis, and phenylpropanoid biosynthesis pathways. There were 1209 DEGs specifically induced only in cotton plants inoculated with V. dahliae in the presence of the biocontrol fungus CEF-082, and not when cotton plants were only inoculated with V. dahliae. GO analysis revealed that these DEGs were enriched mainly in the following terms: ROS metabolic process, H2O2 metabolic process, defense response, superoxide dismutase activity, and antioxidant activity. Moreover, many genes, such as ERF, CNGC, FLS2, MYB, GST and CML, that regulate crucial points in defense-related pathways were identified and may contribute to V. dahliae resistance in cotton. These results provide a basis for understanding the molecular mechanism by which the biocontrol fungus CEF-082 increases the resistance of cotton to Verticillium wilt. Conclusions: The results of this study showed that CEF-082 could regulate multiple metabolic pathways in cotton. After treatment with V. dahliae, the defense response of cotton plants preinoculated with CEF-082 was strengthened.

scholarly journals The Role of a New Compound Micronutrient Multifunctional Fertilizer against Verticillium dahliae on Cotton

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 81
Author(s):  
Yalin Zhang ◽  
Lihong Zhao ◽  
Zili Feng ◽  
Hongfu Guo ◽  
Hongjie Feng ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Hyphal Growth ◽  
Phenylpropanoid Metabolism ◽  
Nitric Oxide Signaling ◽  
Hypocotyl Tissue ◽  
Micronutrient Fertilizer

Verticillium dahliae Kleb., the causal pathogen of vascular wilt, can seriously reduce the yield and quality of many crops, including cotton (Gossypium hirsutum). To control the harm caused by V. dahliae, considering the environmental pollution of chemical fungicides and their residues, the strategy of plant nutrition regulation is becoming increasingly important as an eco-friendly method for disease control. A new compound micronutrient fertilizer (CMF) found in our previous study could reduce the damage of cotton Verticillium wilt and increase yield. However, there is little information about the mode of action of CMF to control this disease. In the present study, we evaluated the role of CMF against V. dahliae and its mechanism of action in vitro and in vivo. In the laboratory tests, we observed that CMF could inhibit hyphal growth, microsclerotia germination, and reduce sporulation of V. dahliae. Further studies revealed that the biomass of V. dahliae in the root and hypocotyl of cotton seedlings treated with CMF were significantly reduced compared with the control, and these results could explain the decline in the disease index of cotton Verticillium wilt. Furthermore, those key genes involved in the phenylpropanoid metabolism pathway, resistance-related genes defense, and nitric oxide signaling pathway were induced in cotton root and hypocotyl tissue when treated with CMF. These results suggest that CMF is a multifaceted micronutrient fertilizer with roles in inhibiting the growth, development, and pathogenicity of V. dahliae and promoting cotton growth.

Sign in / Sign up

Export Citation Format

Share Document