scholarly journals Walking Together: Cross-Protection, Genome Conservation, and the Replication Machinery of Citrus tristeza virus

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1353
Author(s):  
Svetlana Y. Folimonova ◽  
Diann Achor ◽  
Moshe Bar-Joseph
Keyword(s):  
Citrus Tristeza Virus ◽  
Fluorescent Protein ◽  
Field Tests ◽  
Fruit Trees ◽  
Plant Viruses ◽  
Cross Protection ◽  
Virus Variant ◽  
Tristeza Virus ◽  
Direct Confirmation ◽  
Citrus Tristeza

“Cross-protection”, a nearly 100 years-old virological term, is suggested to be changed to “close protection”. Evidence for the need of such change has accumulated over the past six decades from the laboratory experiments and field tests conducted by plant pathologists and plant virologists working with different plant viruses, and, in particular, from research on Citrus tristeza virus (CTV). A direct confirmation of such close protection came with the finding that “pre-immunization” of citrus plants with the variants of the T36 strain of CTV but not with variants of other virus strains was providing protection against a fluorescent protein-tagged T36-based recombinant virus variant. Under natural conditions close protection is functional and is closely associated both with the conservation of the CTV genome sequence and prevention of superinfection by closely similar isolates. It is suggested that the mechanism is primarily directed to prevent the danger of virus population collapse that could be expected to result through quasispecies divergence of large RNA genomes of the CTV variants continuously replicating within long-living and highly voluminous fruit trees. This review article provides an overview of the CTV cross-protection research, along with a discussion of the phenomenon in the context of the CTV biology and genetics.

scholarly journals Prospects of classical cross protection technique against Citrus tristeza closterovirus in Pakistan: A review

2011 ◽  
Vol 32 (No. 2) ◽  
pp. 74-83 ◽  
Author(s):  
M. Abbas ◽  
M. M Khan ◽  
S. M Mughal ◽  
I. A Khan
Keyword(s):  
Physical Properties ◽  
Citrus Tristeza Virus ◽  
Cross Protection ◽  
Citrus Tree ◽  
Citrus Groves ◽  
Drastic Effect ◽  
Citrus Tristeza Closterovirus ◽  
Tristeza Virus ◽  
Classical Cross ◽  
Citrus Tristeza

In Pakistan citrus groves in general are facing a serious problem of decline that is attributed to different causes. The major cause, however, is the prevalence of citrus virus and virus-like diseases; Citrus tristeza virus (CTV) is of utmost concern. Although CTV has been identified and characterized on the basis of serological and physical properties, no information is available on the strains of CTV in Pakistan. The identification of CTV strains will be helpful in developing strategies to control the decline of citrus trees to a great extent. Many citrus growing countries have successfully used the technique of cross protection to minimize the drastic effect of severe CTV strains. By pre-immunization of the citrus tree with mild strains, the decline can be controlled to increase the life span of the citrus tree. In this study we focus on the possibility of establishing a cross protection technique in Pakistan against the CTV strains.  

scholarly journals Breakdown of Cross-Protection of Grapefruit from Decline-Inducing Isolates of Citrus tristeza virus Following Introduction of the Brown Citrus Aphid

Plant Disease ◽  
2003 ◽  
Vol 87 (9) ◽  
pp. 1116-1118 ◽  
Author(s):  
C. A. Powell ◽  
R. R. Pelosi ◽  
P. A. Rundell ◽  
M. Cohen
Keyword(s):  
Immunosorbent Assay ◽  
Citrus Tristeza Virus ◽  
Cross Protection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Experimental Area ◽  
Toxoptera Citricida ◽  
The Cross ◽  
Tristeza Virus ◽  
Citrus Tristeza

A 21-year-old replicated field planting of 84 ‘Ruby Red’ grapefruit trees cross-protected with three mild isolates of Citrus tristeza virus (CTV) was assessed for decline-inducing and non-decline-inducing isolates of the virus 5 years after the brown citrus aphid (BrCA) (Toxoptera citricida Kirkaldy) first was established in the experimental area. Prior to the introduction of the BrCA, the cross-protecting mild isolates had significantly reduced detectable infection with decline-inducing isolates of CTV for 16 years (average infection of 13% in cross-protected trees compared with 67% in unprotected trees). After the introduction of the BrCA, infections with decline-inducing CTV (measured by enzyme-linked immunosorbent assay) were 57, 81, and 71% for trees protected with three mild isolates, respectively, compared with 95% in unprotected trees. These results suggest that the introduction of BrCA accelerated the breakdown of cross-protection against decline-inducing isolates of CTV in grapefruit.

scholarly journals Citrus tristeza virus P33 Protein Is Required for Efficient Transmission by the Aphid Aphis (Toxoptera) citricidus (Kirkaldy)

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1131
Author(s):  
Turksen Shilts ◽  
Choaa El-Mohtar ◽  
William O. Dawson ◽  
Nabil Killiny
Keyword(s):  
Citrus Tristeza Virus ◽  
Transmission Rate ◽  
Control Strategies ◽  
Virus Transmission ◽  
Plant Viruses ◽  
Transmission Mechanisms ◽  
Infectious Clones ◽  
Underlying Mechanisms ◽  
Tristeza Virus ◽  
Citrus Tristeza

Plant viruses are threatening many valuable crops, and Citrus tristeza virus (CTV) is considered one of the most economically important plant viruses. CTV has destroyed millions of citrus trees in many regions of the world. Consequently, understanding of the transmission mechanism of CTV by its main vector, the brown citrus aphid, Aphis (Toxoptera) citricidus (Kirkaldy), may lead to better control strategies for CTV. The objective of this study was to understand the CTV–vector relationship by exploring the influence of viral genetic diversity on virus transmission. We built several infectious clones with different 5′-proximal ends from different CTV strains and assessed their transmission by the brown citrus aphid. Replacement of the 5′- end of the T36 isolate with that of the T30 strain (poorly transmitted) did not increase the transmission rate of T36, whereas replacement with that of the T68-1 isolate (highly transmitted) increased the transmission rate of T36 from 1.5 to 23%. Finally, substitution of p33 gene of the T36 strain with that of T68 increased the transmission rate from 1.5% to 17.8%. Although the underlying mechanisms that regulate the CTV transmission process by aphids have been explored in many ways, the roles of specific viral proteins are still not explicit. Our findings will improve our understanding of the transmission mechanisms of CTV by its aphid vector and may lead to the development of control strategies that interfere with its transmission by vector.

scholarly journals First field records of the sexuales (males and oviparae) of Toxoptera aurantii (Hemiptera: Aphididae)

Zootaxa ◽  
2011 ◽  
Vol 2836 (1) ◽  
pp. 62
Author(s):  
NICOLÁS PÉREZ HIDALGO ◽  
DAVID MIFSUD
Keyword(s):  
Citrus Tristeza Virus ◽  
Plant Viruses ◽  
Toxoptera Aurantii ◽  
Tristeza Virus ◽  
Citrus Tristeza

Toxoptera aurantii (Boyer de Fonscolombe) is an aphid pest of great agricultural importance, not only due to its polyphagy but mostly due to its ability to transmit various plant viruses e.g. Citrus tristeza virus on Citrus (Blackman & Eastop, 2000). Blackman & Eastop (2000) considered this aphid to be entirely anholocyclic, because no sexual morphs have ever been observed in the field.

scholarly journals Prereaction of Citrus tristeza virus (CTV) Specific Antibodies and Labeled Secondary Antibodies Increases Speed of Direct Tissue Blot Immunoassay for CTV

Plant Disease ◽  
2006 ◽  
Vol 90 (5) ◽  
pp. 675-679 ◽  
Author(s):  
Youjian Lin ◽  
Phyllis A. Rundell ◽  
Lianhui Xie ◽  
Charles A. Powell
Keyword(s):  
Citrus Tristeza Virus ◽  
Plant Viruses ◽  
Specific Antibodies ◽  
Rabbit Igg ◽  
Tissue Blot Immunoassay ◽  
Polymerase Chain ◽  
Bacteria And Fungi ◽  
Secondary Antibodies ◽  
Tristeza Virus ◽  
Citrus Tristeza

An improved direct tissue blot immunoassay (DTBIA) procedure for detection of Citrus tristeza virus (CTV) within 1 h is described. Prints of fresh young stems of citrus plants that were infected or not infected with CTV were made by gently and evenly pressing the fresh-cut surface of the stems onto a nitrocellulose membrane. The tissue blots were air-dried for 5 min, incubated with prereaction solutions of CTV-specific antibodies and labeled secondary antibodies, goat anti-mouse Ig (H+L)-alkaline phosphatase conjugate or goat anti-rabbit IgG alkaline phos-phatase conjugate, for up to 20 min, rinsed with PBST buffer for 5 min, and immersed into an NBT-BCIP substrate solution for 15 to 20 min. Then the blots were rinsed in water for a few seconds to stop the reactions, and the results were observed and recorded under a light microscope. All samples from greenhouse plants that were infected with CTV decline inducing isolate T-36 were positive to CTV-specific polyclonal antibody 1212 (PCA 1212) and monoclonal antibodies 17G11 (MAb 17G11) and MCA13 (MAb MCA13), whereas samples from greenhouse plants infected with non-decline-inducing isolate T-30 were positive to PCA 1212 and MAb 17G11, but not to MAb MCA13. The noninfected greenhouse plants were negative to all of the antibodies. The improved DTBIA was at least as reliable as other immunological procedures and almost as reliable as polymerase chain reaction for detecting CTV in field trees. The improved DTBIA enables the detection of CTV within 1 h by having a prereaction of CTV-specific antibodies and labeled secondary antibodies in solutions before they are applied to the tissue blots. This DTBIA procedure may be useful in detecting other plant viruses and other pathogens such as bacteria and fungi.

Sign in / Sign up

Export Citation Format

Share Document