scholarly journals Tm-22 Resistance in Tomato Requires Recognition of the Carboxy Terminus of the Movement Protein of Tomato Mosaic Virus

1998 ◽  
Vol 11 (6) ◽  
pp. 498-503 ◽  
Author(s):  
Hans Weber ◽  
Artur J. P. Pfitzner

The Tm-22 resistance gene is used in most commercial tomato cultivars for protection against infection with tomato mosaic virus (ToMV). It has been suggested that Tm-22 resistance interferes with viral cell-to-cell movement in plants; ToMV strain ToMV-22 requires two amino acid (aa) exchanges in the carboxy-terminal region of the viral 30-kDa movement protein (at positions 238 and 244) to overcome Tm-22 resistance. For further analysis of this region of the 30-kDa protein, two stop codons were introduced into ToMV movement proteins at aa positions 235 and 237, leading to deletion of the terminal 30 aa. The mutant virus strains were able to infect wild-type tomato plants systemically, suggesting the carboxy-terminal portion of the ToMV 30-kDa protein is dispensable for virus transport in tomato. Even more important, the deletion mutants overcame the Tm-22 resistance gene. These data indicate the carboxy-terminal domain of the ToMV movement protein serves as a recognition target in the context of the Tm-22 resistance gene. Furthermore, expression of the 30-kDa movement protein from wild-type ToMV, but not from ToMV-22, in transgenic tomato plants with the Tm-22 resistance gene led to elicitation of a necrotic reaction in tomato seedlings, showing that the 30-kDa protein on its own is able to induce the plant's defense reaction.

2001 ◽  
Vol 14 (9) ◽  
pp. 1051-1062 ◽  
Author(s):  
Jesús A. Sánchez-Navarro ◽  
John F. Bol

The movement protein (MP) and coat protein (CP) encoded by Alfalfa mosaic virus (AMV) RNA 3 are both required for virus transport. RNA 3 vectors that expressed nonfused green fluorescent protein (GFP), MP:GPF fusions, or GFP:CP fusions were used to study the functioning of mutant MP and CP in protoplasts and plants. C-terminal deletions of up to 21 amino acids did not interfere with the function of the CP in cell-to-cell movement, although some of these mutations interfered with virion assembly. Deletion of the N-terminal 11 or C-terminal 45 amino acids did not interfere with the ability of MP to assemble into tubular structures on the protoplast surface. Additionally, N- or C-terminal deletions disrupted tubule formation. A GFP:CP fusion was targeted specifically into tubules consisting of a wild-type MP. All MP deletion mutants that showed cell-to-cell and systemic movement in plants were able to form tubular structures on the surface of protoplasts. Brome mosaic virus (BMV) MP did not support AMV transport. When the C-terminal 48 amino acids were replaced by the C-terminal 44 amino acids of the AMV MP, however, the BMV/AMV chimeric protein permitted wild-type levels of AMV transport. Apparently, the C terminus of the AMV MP, although dispensable for cell-to-cell movement, confers specificity to the transport process.


2003 ◽  
Vol 84 (3) ◽  
pp. 727-732 ◽  
Author(s):  
E. M. Karger ◽  
O. Yu. Frolova ◽  
N. V. Fedorova ◽  
L. A. Baratova ◽  
T. V. Ovchinnikova ◽  
...  

Replication of tobacco mosaic virus (TMV) is connected with endoplasmic reticulum (ER)-associated membranes at early stages of infection. This study reports that TMV movement protein (MP)-specific protein kinases (PKs) associated with the ER of tobacco were capable of phosphorylating Thr104 in TMV MP. The MP-specific PKs with apparent molecular masses of about 45–50 kDa and 38 kDa were revealed by gel PK assays. Two types of mutations were introduced in TMV MP gene of wild-type TMV U1 genome to substitute Thr104 by neutral Ala or by negatively charged Asp. Mutation of Thr104 to Ala did not affect the size of necrotic lesions induced by the mutant virus in Nicotiana tabacum Xanthi nc. plants. Conversely, mutation of Thr to Asp mimicking Thr104 phosphorylation strongly inhibited cell-to-cell movement. The possible role of Thr104 phosphorylation in TMV MP function is discussed.


Author(s):  
Hagit Hak ◽  
Ziv Spiegelman

Tomato brown rugose fruit virus (ToBRFV) is a new virus of the Tobamovirus genus, causing substantial damage to tomato crops. Reports of recent ToBRFV outbreaks from around the world indicate an emerging global epidemic. ToBRFV overcomes all tobamovirus resistances in tomato, including the durable Tm-22 resistance gene, which had been effective against multiple tobamoviruses. Here, we show that the ToBRFV movement protein (MPToBRFV) enables the virus to evade Tm-22 resistance. Transient expression of MPToBRFV failed to activate the Tm-22 resistance response. Replacement of the original MP sequence of Tomato mosaic virus (ToMV) with MPToBRFV enabled this recombinant virus to infect Tm-22 resistant plants. Using hybrid protein analysis, we show that the elements required to evade Tm-22 are located between MPToBRFV amino acids 1 and 216, and not the C terminus as previously assumed. Analysis of ToBRFV systemic infection in tomato revealed that ToBRFV spreads slower compared to ToMV. Interestingly, replacement of Tobacco mosaic virus (TMV) and ToMV MPs with MPToBRFV caused an attenuation of systemic infection of both viruses. Cell-to-cell movement analysis showed that MPToBRFV moves less effectively compared to the TMV MP (MPTMV). These findings suggest that overcoming Tm-22 is associated with attenuated MP function. This may explain the high durability of Tm-22 resistance, which had remained unbroken for over 60 years.


2000 ◽  
Vol 13 (3) ◽  
pp. 297-308 ◽  
Author(s):  
Yu-Ming Hou ◽  
Rick Sanders ◽  
Virgina M. Ursin ◽  
Robert L. Gilbertson

Transgenic tomato plants expressing wild-type or mutated BV1 or BC1 movement proteins from Bean dwarf mosaic virus (BDMV) were generated and examined for phenotypic effects and resistance to Tomato mottle virus (ToMoV). Fewer transgenic plants were recovered with the wild-type or mutated BC1 genes, compared with the wild-type or mutated BV1 genes. Transgenic tomato plants expressing the wild-type or mutated BV1 proteins appeared normal. Interestingly, although BDMV induces only a symptomless infection in tomato (i.e., BDMV is not well adapted to tomato), transgenic tomato plants expressing the BDMV BC1 protein showed a viral disease-like phenotype (i.e., stunted growth, and leaf mottling, curling, and distortion). This suggests that the symptomless phenotype of BDMV in tomato is not due to a host-specific defect in the BC1 protein. One transgenic line expressing the BC1 gene did not show the viral disease-like phenotype. This was associated with a deletion in the 3′ region of the gene, which resulted in expression of a truncated BC1 protein. Several R0 plants, expressing either wild-type or mutated BV1 or BC1 proteins, showed a significant delay in ToMoV infection, compared with non-transformed plants. R1 progeny plants also showed a significant delay in ToMoV infection, but this delay was less than that in the R0 parents. These results also demonstrate that expression of viral movement proteins, in transgenic plants, can have deleterious effects on various aspects of plant development.


2007 ◽  
Vol 88 (3) ◽  
pp. 1034-1040 ◽  
Author(s):  
Diana Pohl ◽  
Christina Wege

In contrast to previous observations on phloem-limited geminiviruses supported in movement andaccumulation by RNA viruses such as cucumo- and tobamoviruses, tissue infiltration by Abutilon mosaic virus (AbMV) was enhanced by neither Tobacco mosaic virus nor Tomato mosaic virus (ToMV) in two different hosts, Nicotiana benthamiana and tomato. Both tobamoviruses exerted a negative effect on the DNA virus, resulting in a decrease in AbMV accumulation and significantly reduced infectivity in N. benthamiana. Despite these unexpected molecular observations, a striking synergistic enhancement in pathogenicity occurred with respectto stunting and necrosis. In situ hybridization revealed that this was not due to any alteration of tissue infiltration by AbMV, which also remained limited to the phloem in the mixed infections. Transgenically expressed ToMV 30K movement protein was not able to induce phloemescape of AbMV in tomato plants and did not lead to any obvious change in begomovirus symptomatology.


2002 ◽  
Vol 83 (12) ◽  
pp. 3187-3197 ◽  
Author(s):  
Gabrièle Drugeon ◽  
Isabelle Jupin

Plant viruses move to adjacent cells with the use of virus-encoded cell-to-cell movement proteins. Using proteins produced by in vitro translation, we present evidence that the ‘69K’ movement protein of Turnip yellow mosaic virus (TYMV) is recognized as a substrate for the attachment of polyubiquitin chains and for subsequent rapid and selective proteolysis by the proteasome, the ATP-dependent proteolytic system present in reticulocyte lysate. Truncation of the 69K protein suggests the existence of two degradation signals within its sequence. We propose that selective degradation of virus movement proteins may contribute to the previously reported transient nature of their accumulation during infection.


2020 ◽  
Author(s):  
Hagit Hak ◽  
Ziv Spiegelman

Tomato brown rugose fruit virus (ToBRFV) is a new virus of the Tobamovirus genus, causing substantial damage to tomato crops in the Middle East. Reports of recent ToBRFV outbreaks from around the world indicate an emerging global epidemic. ToBRFV overcomes all tobamovirus resistances in tomato, including the durable Tm-22 resistance gene. Here, we show that the ToBRFV movement protein (MPToBRFV) is the cause for overcoming Tm-22 resistance. Transient expression of MPToBRFV failed to activate the Tm-22 resistance response. Replacement of the original MP sequences of Tomato mosaic virus (ToMV) with MPToBRFV enabled this recombinant virus to overcome Tm-22 resistance. Hybrid protein analysis revealed that the resistance-breaking elements are located between MPToBRFV amino acids 1 and 216, and not the C terminus as previously assumed. Interestingly, replacement of Tobacco mosaic virus (TMV) and ToMV MPs with MPToBRFV caused an attenuation of systemic infection of both viruses. Cell-to-cell movement analysis revealed that MPToBRFV moves less effectively compared to the TMV MP (MPTMV). These findings suggest that overcoming Tm-22 is associated with attenuated MP function. This viral fitness cost may explain the high durability of Tm-22 resistance, which had remained unbroken for over 60 years.


2004 ◽  
Vol 85 (6) ◽  
pp. 1751-1761 ◽  
Author(s):  
Atsushi Takeda ◽  
Masanori Kaido ◽  
Tetsuro Okuno ◽  
Kazuyuki Mise

The 3a movement protein (MP) plays a central role in the movement of Brome mosaic virus (BMV). To identify the functional regions in BMV MP, 24 alanine-scanning (AS) MP mutants of BMV were constructed. Infectivity of the AS mutants in the host plant Chenopodium quinoa showed that the central region of BMV MP is important for viral movement and both termini of BMV MP have effects on the development of systemic symptoms. A green-fluorescent-protein-expressing RNA3-based BMV vector containing a 2A sequence from Foot-and-mouth disease virus was also constructed. Using this vector, two AS mutants that showed more efficient cell-to-cell movement than wild-type BMV were identified. The MPs of these two AS mutants, which have mutations at their C termini, mediated cell-to-cell movement independently of coat protein (CP), unlike wild-type BMV MP. Furthermore, a BMV mutant with a truncation in the C-terminal 42 amino acids of MP was also able to move from cell to cell without CP, but did not move systemically, even in the presence of CP. These results and an encapsidation analysis suggest that the C terminus of BMV MP is involved in the requirement for CP in cell-to-cell movement and plays a role in long-distance movement. Furthermore, the ability to spread locally and form virions is not sufficient for the long-distance movement of BMV. The roles of MP and CP in BMV movement are discussed.


Sign in / Sign up

Export Citation Format

Share Document