Vascular coating: a barrier to colonization by the pathogen in Verticillium wilt of tomato

1989 ◽  
Vol 67 (2) ◽  
pp. 600-607 ◽  
Author(s):  
Jane Robb ◽  
D. A. Powell ◽  
P. F. S. Street
Keyword(s):  
Disease Resistance ◽  
Verticillium Wilt ◽  
Water Samples ◽  
Light Microscope ◽  
Trapping Site ◽  
Symptom Expression ◽  
Susceptible Tomato ◽  
Ve Gene ◽  
Verticillium Albo Atrum

Massive infusion of conidia of Verticillium albo-atrum Reinke & Berthier induced synchronous secretion of vascular coating in the petiolar xylem vessels of resistant and susceptible tomato near-isolines. More coating formed earlier in resistant than in susceptible plants. In the susceptible plants secretion was delayed in colonized trapping site vessels, but initiated in surrounding uncolonized ones. Controls were infused with water. Samples were quantified by light microscope assay techniques at 18, 48, and 120 h postinoculation for the following parameters: (i) delayed coating effect, (ii) overall coating capacity, and (iii) ability of fungus to "escape" laterally from trapping site vessels. The results showed that susceptibility to Verticillium was absolutely correlated with the presence of the delayed coating effect in the plant and increased ability of the fungus to spread laterally. Treatment of inoculated resistant plants with an inhibitor of coating secretion resulted in conversion to the susceptible phenotype. The progeny of a genetic backcross for the dominant (Ve) and recessive (ve) alleles at the Ve locus (Velve × velve) were assayed for the same parameters as well as for disease resistance based on symptom expression. The results confirmed the previous observations and suggested that in tomato the delayed phenotype is recessive. The data strongly supports two hypotheses: (i) coating forms a barrier against fungal penetration and (ii) the timing of the coating response in trapping site vessels results, directly or indirectly, from expression of the Ve gene.

scholarly journals Wood Tannins - Isolation and Significance in Host Resistance to Verticillium Wilt Disease

1967 ◽  
Vol 20 (2) ◽  
pp. 475 ◽  
Author(s):  
TC Somers ◽  
AF Harrison
Keyword(s):  
Heart Disease ◽  
Disease Resistance ◽  
Verticillium Wilt ◽  
Host Resistance ◽  
Total Phenolics ◽  
Resistance Mechanisms ◽  
Wilt Disease ◽  
Fivefold Increase ◽  
Verticillium Albo Atrum

Apricot trees often recover from the "black heart" disease incited by the fungus Verticillium albo-atrum Reinke & Berthold, and a characteristic of such resistant trees is that the infected wood becomes dark brown to black in colour (Dufrenoy and Dufrenoy 1927). The fungus dies 1-6 months after it has colonized the wood (Taylor 1963). Analysis of total phenolics by the Folin-Denis assay showed an approximate fivefold increase (to about 60 mgjg wood) compared with that of uninfected wood of the same branch, and suggested their involvement in disease resistance mechanisms.

The colonization ratio: a measure of pathogen invasiveness and host resistance in Verticillium wilt of alfalfa

1989 ◽  
Vol 67 (2) ◽  
pp. 365-370 ◽  
Author(s):  
A. G. Newcombe ◽  
Y. A. Papadopoulos ◽  
Jane Robb ◽  
B. R. Christie
Keyword(s):  
Disease Resistance ◽  
Verticillium Wilt ◽  
Host Resistance ◽  
Quantitative Measure ◽  
Pathogen Resistance ◽  
Symptom Expression ◽  
Symptom Evaluation ◽  
Spore Trapping ◽  
Disease Free ◽  
Trapping Sites

Seeds of four alfalfa cultivars were grown and the plants cloned by rooting cuttings. Individual plants were root-dip inoculated with Verticillium albo-atrum Reinke and Berthold, and scored for relative pathogen resistance by symptom evaluation and reisolation of the fungus during a 7-month period. Nine individual plants were selected: two were resistant to colonization and symptom expression, two remained colonized but were resistant to symptom expression, and five were susceptible. Disease-free cuttings of each selected plant were infused with a mixture of conidia and red vinyl particles which mark primary spore trapping sites. At 168-h postinoculation the colonization ratio was determined for each sample. The colonization ratio is a reliable quantitative measure of invasiveness which is calculated by scoring a section of tissue for the number of secondary colonization sites established per primary trapping site in a given unit of time. The colonization ratio values of the nine selected plants were correlated with the level of disease resistance as determined by two methods: (i) symptom evaluation and pathogen resiolation, and (ii) genetic S1 analysis. The colonization ratio, a new measure of fungal invasiveness and host resistance, might be useful in the breeding and assessment of alfalfa cultivars with resistance to Verticillium wilt.

scholarly journals Dynamic characteristics and functional analysis provide new insights into long non-coding RNA responsive to Verticillium dahliae infection in Gossypium hirsutum

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Guoning Wang ◽  
Xingfen Wang ◽  
Yan Zhang ◽  
Jun Yang ◽  
Zhikun Li ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Verticillium Wilt ◽  
Dynamic Characteristics ◽  
Target Genes ◽  
Acid Metabolism ◽  
Expression Profiles ◽  
Enrichment Analysis ◽  
Alpha Linolenic Acid ◽  
Non Coding Rna ◽  
Long Non Coding Rna

Abstract Background Verticillium wilt is a widespread and destructive disease, which causes serious loss of cotton yield and quality. Long non-coding RNA (lncRNA) is involved in many biological processes, such as plant disease resistance response, through a variety of regulatory mechanisms, but their possible roles in cotton against Verticillium dahliae infection remain largely unclear. Results Here, we measured the transcriptome of resistant G. hirsutum following infection by V. dahliae and 4277 differentially expressed lncRNAs (delncRNAs) were identified. Localization and abundance analysis revealed that delncRNAs were biased distribution on chromosomes. We explored the dynamic characteristics of disease resistance related lncRNAs in chromosome distribution, induced expression profiles, biological function, and these lncRNAs were divided into three categories according to their induced expression profiles. For the delncRNAs, 687 cis-acting pairs and 14,600 trans-acting pairs of lncRNA-mRNA were identified, which indicated that trans-acting was the main way of Verticillium wilt resistance-associated lncRNAs regulating target mRNAs in cotton. Analyzing the regulation pattern of delncRNAs revealed that cis-acting and trans-acting lncRNAs had different ways to influence target genes. Gene Ontology (GO) enrichment analysis revealed that the regulatory function of delncRNAs participated significantly in stimulus response process, kinase activity and plasma membrane components. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that delncRNAs participated in some important disease resistance pathways, such as plant-pathogen interaction, alpha-linolenic acid metabolism and plant hormone signal transduction. Additionally, 21 delncRNAs and 10 target genes were identified as being involved in alpha-linolenic acid metabolism associated with the biosynthesis of jasmonic acid (JA). Subsequently, we found that GhlncLOX3 might regulate resistance to V. dahliae through modulating the expression of GhLOX3 implicated in JA biosynthesis. Further functional analysis showed that GhlncLOX3-silenced seedlings displayed a reduced resistance to V. dahliae, with down-regulated expression of GhLOX3 and decreased content of JA. Conclusion This study shows the dynamic characteristics of delncRNAs in multiaspect, and suggests that GhlncLOX3-GhLOX3-JA network participates in response to V. dahliae invasion. Our results provide novel insights for genetic improvement of Verticillium wilt resistance in cotton using lncRNAs.

scholarly journals Verticillium wilt (Verticillium albo-atrum) on Medicago sativa (alfalfa) in Iran

2004 ◽  
Vol 53 (6) ◽  
pp. 812-812 ◽  
Author(s):  
M. Ghalandar ◽  
E. Clewes ◽  
D. J. Barbara ◽  
R. Zare ◽  
A. Heydari
Keyword(s):  
Medicago Sativa ◽  
Verticillium Wilt ◽  
Verticillium Albo Atrum

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.

Verticillium wilt of chrysanthemum: colonization of leaves in relation to symptom development

1971 ◽  
Vol 49 (2) ◽  
pp. 181-185 ◽  
Author(s):  
R. Hall ◽  
L. V. Busch
Keyword(s):  
Verticillium Wilt ◽  
Significant Contribution ◽  
Vascular System ◽  
Symptom Expression ◽  
Rapid Rise ◽  
Symptom Development ◽  
Flower Buds ◽  
Advanced Stages ◽  
Wilt Symptom ◽  
Leaf Exudate

The vascular system of leaves of chrysanthemum plants inoculated with Verticillium dahliae was invaded by mycelium before the appearance of visible wilt symptoms. After flower buds appeared a rapid rise in the number of propagules of fungus in the leaf was followed by a rise in severity of visible wilt symptom expression and conductivity of leaf exudate. Those portions of the leaf with the most advanced stages of wilt contained the greatest amounts of fungus. It is suggested that the mycelium within the leaf makes a significant contribution to the development of symptoms of wilt.

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