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Rob W. Briddon - One of the best experts on this subject based on the ideXlab platform.

  • frequent occurrence of mungbean yellow mosaic india virus in tomato leaf curl disease affected tomato in oman
    Scientific Reports, 2019
    Co-Authors: Muhammad Shafiq Shahid, Muhammad Shafiq, M Ilyas, Amir Raza, M N Alsadrani, Abdullah M Alsadi, Rob W. Briddon
    Abstract:

    Next generation sequencing (NGS) of DNAs amplified by rolling circle amplification from 6 tomato (Solanum lycopersicum) plants with leaf curl symptoms identified a number of monopartite begomoviruses, including Tomato yellow leaf curl virus (TYLCV), and a Betasatellite (Tomato leaf curl Betasatellite [ToLCB]). Both TYLCV and ToLCB have previously been identified infecting tomato in Oman. Surprisingly the NGS results also suggested the presence of the bipartite, legume-adapted begomovirus Mungbean yellow mosaic Indian virus (MYMIV). The presence of MYMIV was confirmed by cloning and Sanger sequencing from four of the six plants. A wider analysis by PCR showed MYMIV infection of tomato in Oman to be widespread. Inoculation of plants with full-length clones showed the host range of MYMIV not to extend to Nicotiana benthamiana or tomato. Inoculation to N. benthamiana showed TYLCV to be capable of maintaining MYMIV in both the presence and absence of the Betasatellite. In tomato MYMIV was only maintained by TYLCV in the presence of the Betasatellite and then only at low titre and efficiency. This is the first identification of TYLCV with ToLCB and the legume adapted bipartite begomovirus MYMIV co-infecting tomato. This finding has far reaching implications. TYLCV has spread around the World from its origins in the Mediterranean/Middle East, in some instances, in live tomato planting material. The results here may suggest that begomoviruses which do not commonly infect tomato, such as MYMIV, could be spread as a passenger of TYLCV in tomato.

  • identification of pea leaf distortion virus and ludwigia leaf distortion Betasatellite associated with yellow leaf curl disease of lima bean in nepal
    Australasian Plant Pathology, 2019
    Co-Authors: Muhammad Shahid, B. J. Pudashini, Keiko T Natsuaki, Muhammad Shafiq, G B Khatrichhetri, Rob W. Briddon
    Abstract:

    Lima bean (Phaseolus lunatus) plants exhibiting yellow mosaic and stunted growth symptoms, typical of begomovirus infection, were collected in Rampur city Nepal. Symptomatic plants were shown to be infected by a monopartite begomovirus in association with a Betasatellite. The two begomovirus isolates associated with the disease showed 98.7% nucleotide sequence identity to previously characterized isolates of the recently identified begomovirus species Pea leaf distortion virus (PLDV) from Nepal. The associated Betasatellite isolates showed highest nucleotide sequence identity at 99% to Ludwigia leaf distortion Betasatellite (LuLDB) from Nepal. This is the first identification of PLDV and LuLDB infecting the grain legume Phaseolus lunatus.

  • Maintenance of Cotton Leaf Curl Multan Betasatellite by Tomato Leaf Curl New Delhi Virus—Analysis by Mutation
    Frontiers Media S.A., 2017
    Co-Authors: Zafar Iqbal, Shahid Mansoor, Muhammad Shafiq, Irfan Ali, Rob W. Briddon
    Abstract:

    Viruses of the genus Begomovirus (family Geminiviridae) are economically important phytopathogens that are transmitted plant-to-plant by the whitefly Bemisia tabaci. Most Old World (OW) begomoviruses are monopartite and many of these interact with symptoms and host range determining Betasatellites. Tomato leaf curl New Delhi virus (ToLCNDV) is one of only a few OW begomoviruses with a bipartite genome (components known as DNA A and DNA B). Four genes [AV2, coat protein (CP), transcriptional-activator protein (TrAP), and AC4] of ToLCNDV were mutated and the effects of the mutations on infectivity, symptoms and the ability to maintain Cotton leaf curl Multan Betasatellite (CLCuMuB) were investigated. Infectivity and virus/Betasatellite DNA titer were assessed by Southern blot hybridization, PCR, and quantitative PCR. The results showed TrAP of ToLCNDV to be essential for maintenance of CLCuMuB and AV2 to be important only in the presence of the DNA B. AC4 was found to be important for the maintenance of CLCuMuB in the presence of, but indispensable in the absence of, the DNA B. Rather than being required for maintenance, the CP was shown to possibly interfere with maintenance of the Betasatellite. The findings show that the interaction between a bipartite begomovirus and a Betasatellite is more complex than just trans-replication. Clearly, multiple levels of interactions are present and such associations can cause additional significant losses to crops although the interaction may not be stable

  • Maintenance of an Old World Betasatellite by a New World helper begomovirus and possible rapid adaptation of the Betasatellite
    2016
    Co-Authors: Muhammad Shah Nawaz-ul-rehman, Shahid Mansoor, Rob W. Briddon, Claude M. Fauquet
    Abstract:

    Begomoviruses (family Geminiviridae) cause major losses to crops throughout the tropical regions of the world. Begomoviruses originating from the New World (NW) and the Old World (OW) are genetically distinct. Whereas the majority of OW begomoviruses have monopartite genomes and whereas most of these associate with a class of symptom-modulating satellites (known as Betasatellites), the genomes of NW begomoviruses are exclusively bipartite and do not associate with satellites. Here, we show for the first time that a Betasatellite (cotton leaf curl Multan Betasatellite [CLCuMuB]) associated with a serious disease of cotton across southern Asia is capable of interacting with a NW begomovirus. In the presence of CLCuMuB, the symptoms of the NW cabbage leaf curl virus (CbLCuV) are enhanced in Nicotiana benthamiana. However, CbLCuV was unable to interact with a second Betasatellite, chili leaf curl Betasatellite. Although CbLCuV can transreplicate CLCuMuB, satellite accumulation levels in plants were low. However, progeny CLCuMuB isolated after just one round of infection with CbLCuV contained numerous mutations. Reinoculation of one such progeny CLCuMuB with CbLCuV to N. benthamiana yielded infections with significantly higher satellite DNA levels. This suggests that Betasatellites can rapidly adapt for efficient transreplication by a new helper begomovirus, including begomo-viruses originating from the NW. Although the precise mechanism of transreplication of Betasatellites by begomoviruses remains unknown, an analysis of Betasatellite mutants suggests that the sequence(s) require

  • Characterization of non-coding DNA satellites associated with sweepoviruses (genus Begomovirus, Geminiviridae) - definition of a distinct class of begomovirus-associated satellites
    Frontiers Media S.A., 2016
    Co-Authors: Gloria Elozano, Rob W. Briddon, Helena P. Trenado, Elvira Efiallo-olivé, Dorys Echirinos, Francis Egeraud-pouey, Jesús Enavas-castillo
    Abstract:

    Begomoviruses (family Geminiviridae) are whitefly-transmitted, plant-infecting single-stranded DNA viruses that cause crop losses throughout the warmer parts of the World. Sweepoviruses are a phylogenetically distinct group of begomoviruses that infect plants of the family Convolvulaceae, including sweet potato (Ipomoea batatas). Two classes of subviral molecules are often associated with begomoviruses, particularly in the Old World; the Betasatellites and the alphasatellites. An analysis of sweet potato and Ipomoea indica samples from Spain and Merremia dissecta samples from Venezuela identified small non-coding subviral molecules in association with several distinct sweepoviruses. The sequences of 18 clones were obtained and found to be structurally similar to tomato leaf curl virus–satellite (ToLCV-sat, the first DNA satellite identified in association with a begomovirus), with a region with significant sequence identity to the conserved region of Betasatellites, an A-rich sequence, a predicted stem-loop structure containing the nonanucleotide TAATATTAC, and a second predicted stem-loop. These sweepovirus-associated satellites join an increasing number of ToLCV-sat-like non-coding satellites identified recently. Although sharing some features with Betasatellites, evidence is provided to suggest that the ToLCV-sat-like satellites are distinct from Betasatellites and should be considered a separate class of satellites, for which the collective name deltasatellites is proposed

Shahid Mansoor - One of the best experts on this subject based on the ideXlab platform.

  • INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY Chili Leaf Curl Betasatellite Enhances Symptoms Induced by Tomato Leaf Curl New Delhi Virus, a Bipartite Begomovirus
    2020
    Co-Authors: Adnan Akhter, Sohail Akhtar, Muhammad Saeed, Shahid Mansoor
    Abstract:

    Abstract Begomovirus disease complexes are the major limiting factor on chilies throughout the Indian subcontinent. The severe symptoms in chilies are associated with multiple begomovirus components. Infectivity assays of Tomato leaf curl New Delhi virus (ToLCNDV) and Chili leaf curl Betasatellite (ChLCB) were conducted. DNA A and DNA B of ToLCNDV isolated from chilies and tomato were infectious and produced leaf curl symptoms when inoculated on Nicotiana benthamiana by biolistic gun method. Co-inoculation of ToLCNDV with ChLCB resulted in the severity of disease symptoms. These results show that interaction of Betasatellite with bipartite begomoviruses may enhance symptoms induced by bipartite viruses. Thus interactions of Betasatellites and symptom enhancement are not limited to monopartite begomoviruses and bipartite begomovirus-Betasatellite interaction presents yet another example of rapid changes in begomovirus complexes that infect important crops in the region

  • identification of a dicot infecting mastrevirus along with alpha and Betasatellite associated with leaf curl disease of spinach spinacia oleracea in pakistan
    Virus Research, 2018
    Co-Authors: M Y Hamza, Muhammad Nouman Tahir, Roma Mustafa, Hira Kamal, Muhammad Zuhaib Khan, Shahid Mansoor
    Abstract:

    Abstract Spinach is a common vegetable crop and very little data is available about its virus infection. Symptomatic leaves of spinach were collected during field survey. Circular DNA molecules were amplified from symptomatic samples using rolling circle amplification (RCA). After restriction analysis, presumed bands of virus and satellites were cloned, sequenced and analyzed. Analysis of sequenced RCA product revealed the presence of chickpea chlorotic dwarf virus (CpCDV; Mastrevirus). Further analyses of the cloned virus showed that strain “C” of CpCDV was present in symptomatic samples of spinach collected from field associated with vein darkening, curling and enations on leaves. Amplification of alpha- and Betasatellites with universal primers was performed. CpCDV showed association with cotton leaf curl Multan Betasatellite (CLCuMB) and cotton leaf curl Multan alphasatellites (CLCuMA). Infectivity analysis of CpCDV and CpCDV/CLCuMB were done in N. benthamiana using particle bombardment method and the results showed that CpCDV was able to transreplicates CLCuMB in this host. To our knowledge, this is the first report of a dicot infecting mastrevirus (CpCDV) along with CLCuMB and CLCuMA associated with leaf curl disease of spinach in Pakistan. The significance of the results is discussed.

  • Maintenance of Cotton Leaf Curl Multan Betasatellite by Tomato Leaf Curl New Delhi Virus—Analysis by Mutation
    Frontiers Media S.A., 2017
    Co-Authors: Zafar Iqbal, Shahid Mansoor, Muhammad Shafiq, Irfan Ali, Rob W. Briddon
    Abstract:

    Viruses of the genus Begomovirus (family Geminiviridae) are economically important phytopathogens that are transmitted plant-to-plant by the whitefly Bemisia tabaci. Most Old World (OW) begomoviruses are monopartite and many of these interact with symptoms and host range determining Betasatellites. Tomato leaf curl New Delhi virus (ToLCNDV) is one of only a few OW begomoviruses with a bipartite genome (components known as DNA A and DNA B). Four genes [AV2, coat protein (CP), transcriptional-activator protein (TrAP), and AC4] of ToLCNDV were mutated and the effects of the mutations on infectivity, symptoms and the ability to maintain Cotton leaf curl Multan Betasatellite (CLCuMuB) were investigated. Infectivity and virus/Betasatellite DNA titer were assessed by Southern blot hybridization, PCR, and quantitative PCR. The results showed TrAP of ToLCNDV to be essential for maintenance of CLCuMuB and AV2 to be important only in the presence of the DNA B. AC4 was found to be important for the maintenance of CLCuMuB in the presence of, but indispensable in the absence of, the DNA B. Rather than being required for maintenance, the CP was shown to possibly interfere with maintenance of the Betasatellite. The findings show that the interaction between a bipartite begomovirus and a Betasatellite is more complex than just trans-replication. Clearly, multiple levels of interactions are present and such associations can cause additional significant losses to crops although the interaction may not be stable

  • Characterization of a Begomovirus-Betasatellite Complex, Producing Defective Molecules in Spinach (Spinacia oleracea L.), a New Host for Begomovirus and Betasatellite Complex in Pakistan
    Hanrimwon Publishing Company, 2017
    Co-Authors: Muhammad Nouman Tahir, Imran Amin, Amir Hameed, Shahid Mansoor
    Abstract:

    Spinach is a vegetable crop which is widely grown over a large area especially in Punjab province of Pakistan. Leaf curling and enations on spinach plant collected shown to be associated with the begomovirus Pedilanthus leaf curl virus (PeLCV) and Shahdadpur strain of Cotton leaf curl Multan Betasatellite (CLCuMBSha). Defective molecules of half and quarter size derived from monopartite begomoviruses are usually generated by the deletion of virion-sense sequences. Characterization of defective molecules of PeLCV from spinach revealed that the molecules of half the size are derived from the deletion of complementary-sense genes while quarter size molecule appears to have evolved by further deletion. This is the first report of the begomovirus-Betasatellite complex on spinach and unusual defective molecules derived from deletion of complementary-sense genes in Pakistan

  • Maintenance of an Old World Betasatellite by a New World helper begomovirus and possible rapid adaptation of the Betasatellite
    2016
    Co-Authors: Muhammad Shah Nawaz-ul-rehman, Shahid Mansoor, Rob W. Briddon, Claude M. Fauquet
    Abstract:

    Begomoviruses (family Geminiviridae) cause major losses to crops throughout the tropical regions of the world. Begomoviruses originating from the New World (NW) and the Old World (OW) are genetically distinct. Whereas the majority of OW begomoviruses have monopartite genomes and whereas most of these associate with a class of symptom-modulating satellites (known as Betasatellites), the genomes of NW begomoviruses are exclusively bipartite and do not associate with satellites. Here, we show for the first time that a Betasatellite (cotton leaf curl Multan Betasatellite [CLCuMuB]) associated with a serious disease of cotton across southern Asia is capable of interacting with a NW begomovirus. In the presence of CLCuMuB, the symptoms of the NW cabbage leaf curl virus (CbLCuV) are enhanced in Nicotiana benthamiana. However, CbLCuV was unable to interact with a second Betasatellite, chili leaf curl Betasatellite. Although CbLCuV can transreplicate CLCuMuB, satellite accumulation levels in plants were low. However, progeny CLCuMuB isolated after just one round of infection with CbLCuV contained numerous mutations. Reinoculation of one such progeny CLCuMuB with CbLCuV to N. benthamiana yielded infections with significantly higher satellite DNA levels. This suggests that Betasatellites can rapidly adapt for efficient transreplication by a new helper begomovirus, including begomo-viruses originating from the NW. Although the precise mechanism of transreplication of Betasatellites by begomoviruses remains unknown, an analysis of Betasatellite mutants suggests that the sequence(s) require

Rakesh Tuli - One of the best experts on this subject based on the ideXlab platform.

  • Association of Satellites with a Mastrevirus in Natural Infection: Complexity of Wheat Dwarf India Virus Disease
    2016
    Co-Authors: Jitendra Kumar, Jitesh Kumar, Sudhir P. Singh, Rakesh Tuli
    Abstract:

    In contrast to begomoviruses, mastreviruses have not previously been shown to interact with satellites. This study reports the first identification of the association of satellites with a mastrevirus in field-grown plants. Two alphasatellite species were de-tected in different field samples of wheat infected withWheat dwarf India virus (WDIV), a Cotton leaf curl Multan alphasatel-lite (CLCuMA) and a Guar leaf curl alphasatellite (GLCuA). In addition to the alphasatellites, a Betasatellite, Ageratum yellow leaf curl Betasatellite (AYLCB), was also identified in the wheat samples. No begomovirus was detected in the wheat samples, thus establishing association of the above-named satellites withWDIV. Agrobacterium-mediated inoculation ofWDIV in wheat, in the presence of either of the alphasatellites or the Betasatellite, resulted in infections inducing more severe symptoms.WDIV efficiently maintained each of the alphasatellites and the Betasatellite in wheat. The satellites enhanced the level ofWDIVDNA in wheat. Inoculation of the satellites isolated from wheat with various begomoviruses intoNicotiana tabacum demonstrated that these remain capable of interacting with the viruses with which they were first identified. Virus-specific small RNAs accu-mulated in wheat upon infection withWDIV but were lower in abundance in plants coinfected with the satellites, suggesting that both the alphasatellites and the Betasatellite suppress RNA silencing. These results suggest that the selective advantage for the maintenance of the alphasatellites and the Betasatellite byWDIV in the field is in overcoming RNA silencing-mediated host defense

  • senna leaf curl virus a novel begomovirus identified in senna occidentalis
    Archives of Virology, 2016
    Co-Authors: Anshu Alok, Rakesh Tuli, Jitesh Kumar, Jitendra Kumar
    Abstract:

    Begomoviruses are whitefly-transmitted, single-stranded DNA viruses that infect a variety of cultivated (crop) and non-cultivated (weed) plants. The present study identified a novel begomovirus and satellites (alpha- and Betasatellite) in Senna occidentalis (syn. Cassia occidentalis) showing leaf curl symptoms. The begomovirus shared a maximum sequence identity of 88.6 % with french bean leaf curl virus (JQ866297), whereas the alphasatellite and the Betasatellite shared identities of 98 % and 90 % with ageratum yellow vein India alphasatellite (LK054802) and papaya leaf curl Betasatellite (HM143906), respectively. No other begomovirus or satellites were detected in the suspected plants. We propose to name the virus “senna leaf curl virus” (SenLCuV).

  • βc1 is a pathogenicity determinant not only for begomoviruses but also for a mastrevirus
    Archives of Virology, 2014
    Co-Authors: Jitendra Kumar, Jitesh Kumar, Sudhir P. Singh, Rakesh Tuli
    Abstract:

    βC1 proteins, encoded by Betasatellites, are known to be pathogenicity determinants, and they are responsible for symptom expression in many devastating diseases caused by begomoviruses. We report the involvement of βC1 in pathogenicity determination of a mastrevirus. Analysis of field samples of wheat plants containing wheat dwarf India virus (WDIV) revealed the presence of a full-length and several defective Betasatellite molecules. The detected Betasatellite was identified as ageratum yellow leaf curl Betasatellite (AYLCB). No begomovirus was detected in any of the samples. The full-length AYLCB contained an intact βC1 gene, whereas the defective molecules contained complete or partial deletions of βC1. Agroinoculation of wheat with the full-length AYLCB and WDIV or of tobacco with ageratum enation virus enhanced the pathogenicity and accumulation of the respective viruses, whereas the defective molecules could not. This study indicates that βC1 is a pathogenicity determinant for WDIV and can interact functionally not only with begomoviruses but also with a mastrevirus.

  • association of satellites with a mastrevirus in natural infection complexity of wheat dwarf india virus disease
    Journal of Virology, 2014
    Co-Authors: Jitesh Kumar, Sudhir P. Singh, Rakesh Tuli
    Abstract:

    In contrast to begomoviruses, mastreviruses have not previously been shown to interact with satellites. This study reports the first identification of the association of satellites with a mastrevirus in field-grown plants. Two alphasatellite species were detected in different field samples of wheat infected with Wheat Dwarf India Virus (WDIV), a Cotton leaf curl Multan alphasatellite (CLCuMA) and a Guar leaf curl alphasatellite (GLCuA). In addition to the alphasatellites, a Betasatellite, Ageratum yellow leaf curl Betasatellite (AYLCB), was also identified in the wheat samples. No begomovirus was detected in the wheat samples, thus establishing association of the above-named satellites with WDIV. Agrobacterium-mediated inoculation of WDIV in wheat, in the presence of either of the alphasatellites or the Betasatellite, resulted in infections inducing more severe symptoms. WDIV efficiently maintained each of the alphasatellites and the Betasatellite in wheat. The satellites enhanced the level of WDIV DNA in wheat. Inoculation of the satellites isolated from wheat with various begomoviruses into Nicotiana tabacum demonstrated that these remain capable of interacting with the viruses with which they were first identified. Virus-specific small RNAs accumulated in wheat upon infection with WDIV but were lower in abundance in plants coinfected with the satellites, suggesting that both the alphasatellites and the Betasatellite suppress RNA silencing. These results suggest that the selective advantage for the maintenance of the alphasatellites and the Betasatellite by WDIV in the field is in overcoming RNA silencing-mediated host defense. IMPORTANCE Wheat is the most widely cultivated cereal crop in the world. A number of viruses are important pathogens of wheat, including the viruses of the genus Mastrevirus, family Geminiviridae. This study reports the association of subgenomic components, called satellites (alpha- and Betasatellites), with a mastrevirus, Wheat Dwarf India Virus (WDIV), isolated from two distant locations in India. This study reports the first identification of the satellites in a monocot plant. The satellites enhanced accumulation of WDIV and severity of disease symptoms. The satellites lowered the concentration of virus-specific small RNAs in wheat plants, indicating their silencing suppressor activity. The involvement of the satellites in symptom severity of the mastrevirus can have implications in the form of economic impact of the virus on crop yield. Understanding the role of the satellites in disease severity is important for developing disease management strategies.

  • 1 Association of satellites with a mastrevirus in natural infection: complexity of 1 Wheat dwarf India virus disease 2 3
    2014
    Co-Authors: Jitendra Kumar, Jitesh Kumar, Sudhir P. Singh, Rakesh Tuli
    Abstract:

    ABSTRACT 23 In contrast to begomoviruses, mastreviruses have not previously been shown to interact with 24 satellites. This manuscript reports the first identification of the association of satellites with a 25 mastrevirus in field-grown plants. Two alphasatellite species were detected in different field 26 samples of wheat infected with Wheat dwarf India virus (WDIV)- one Cotton leaf curl Multan 27 alphasatellite (CLCuMA) and the other Guar leaf curl alphasatellite (GLCuA). In addition to the 28 alphasatellites, a Betasatellite, Ageratum yellow leaf curl Betasatellite (AYLCB), was also 29 identified in the wheat samples. No begomovirus was detected in the wheat samples, thus 30 establishing association of the above satellites with WDIV. Agrobacterium-mediated inoculation 31 of WDIV in wheat, in the presence of either of the alphasatellites or the Betasatellite, resulted in 32 infections inducing more severe symptoms. WDIV efficiently maintained each of the 33 alphasatellites and the Betasatellite in wheat. The satellites enhanced the level of WDIV DNA in 34 wheat. Inoculation of the satellites isolated from wheat with various begomoviruses into 35 Nicotiana tabacum demonstrated that these remain capable of interacting with the viruses with 36 which they were first identified. Virus-specific small RNAs accumulated in wheat upon infection 3

Xueping Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Identification and Analysis of Potential Genes Regulated by an Alphasatellite (TYLCCNA) that Contribute to Host Resistance against Tomato Yellow Leaf Curl China Virus and Its Betasatellite (TYLCCNV/TYLCCNB) Infection in Nicotiana benthamiana
    MDPI AG, 2019
    Co-Authors: Chaohu Luo, Xueping Zhou, Liling Zhao, Zhan Qi Wang, Xianan Liu, Yan Xie
    Abstract:

    Recently, begomovirus/Betasatellite disease complexes were found to be associated with alphasatellites, and their presence modulated disease symptoms and/or viral DNA accumulation in infected plants. However, the biological functions of alphasatellites during begomovirus/Betasatellite infections remain unclear. Tomato yellow leaf curl China virus (TYLCCNV) associated with a Betasatellite (TYLCCNB) is a widespread monopartite begomovirus in China. In the Yunnan province of China, the TYLCCNV/TYLCCNB disease complex is found in association with an alphasatellite (TYLCCNA). In this study, in order to explain the mechanisms underlying TYLCCNV/TYLCCNB infection and reductions in viral DNA accumulation caused by TYLCCNA, we analyzed the transcriptome profiles of Nicotiana benthamiana seedlings challenged by TYLCCNV/TYLCCNB or TYLCCNV/TYLCCNB/TYLCCNA using RNA sequencing. In total, 2272 and 1207 differentially expressed genes (DEGs) were identified to respond to TYLCCNV/TYLCCNB and TYLCCNV/TYLCCNB/TYLCCNA infections, respectively. Compared with the DEGs in the TYLCCNV/TYLCCNB-infected N. benthamiana seedlings, the number of DEGs in plants co-infected with TYLCCNV/TYLCCNB + TYLCCNA was significantly reduced. Additionally, 36 DEGs were identified to be regulated by TYLCCNA, six of which were further analyzed using the virus-induced gene silencing (VIGS) approach. Silencing of these six TYLCCNA responsive DEGs caused more severe disease symptoms and higher viral DNA accumulation levels, suggesting that TYLCCNA responsive DEGs may attenuate TYLCCNV/TYLCCNB infection

  • Advances in Understanding Begomovirus Satellites
    Annual review of phytopathology, 2013
    Co-Authors: Xueping Zhou
    Abstract:

    Begomoviruses are numerous and geographically widespread viruses that cause devastating diseases in many crops. Monopartite begomoviruses are frequently associated with Betasatellites or alphasatellites. Both Betasatellite and alphasatellite DNA genomes are approximately half the size of begomovirus DNA genomes. Betasatellites are essential for induction of typical disease symptoms. The βC1 genes encoded by the Betasatellites have important roles in symptom induction, in suppression of transcriptional and posttranscriptional gene silencing, and they can affect jasmonic acid responsive genes. Host plants of begomoviruses have evolved diverse innate defense mechanisms against the βC1 protein to counter these challenges. Alphasatellites have been identified mainly in monopartite begomoviruses that associate with Betasatellites and have no known contributions to pathogenesis of begomovirus-Betasatellite disease complexes. Applications of current molecular tools are facilitating viral diagnosis and the discove...

  • a recombinant begomovirus resulting from exchange of the c4 gene
    Journal of General Virology, 2013
    Co-Authors: Yan Xie, Rob W. Briddon, Huanran Gong, Liling Zhao, Xiaoyang Jiao, Tong Jiang, Bi Wang, Xueping Zhou
    Abstract:

    A begomovirus isolated from Malvastrum coromandelianum and tomato originating from Yunnan province (China) was shown to be representative of a new begomovirus species, for which the name tomato leaf curl Yunnan virus (TLCYnV) is proposed. TLCYnV has high levels of sequence identity to tomato yellow leaf curl China virus (TYLCCNV) across the whole genome, except for sequences encompassing the C4 gene. Agrobacterium-mediated inoculation showed TLCYnV to be highly infectious to a range of plant species but poorly infectious to M. coromandelianum. In contrast to TYLCCNV, TLCYnV was shown to infect tomato in the absence of a Betasatellite. In field-collected samples, TLCYnV was identified most frequently in tomato in which it was not associated with a Betasatellite. Transgenic expression in Nicotiana benthamiana showed that the C4 protein of TYLCCNV did not induce developmental abnormalities, whereas the C4 of TLCYnV induced severe developmental abnormalities, reminiscent of virus symptoms. The genome of TLCYnV was shown to be significantly less methylated in plants than that of TYLCCNV and the C4 protein of TLCYnV was shown to suppress post-transcriptional gene silencing and transcriptional gene silencing more effectively than the C4 of TYLCCNV. The results indicate that TLCYnV evolved from TYLCCNV by recombination, acquiring a more virulent C4, allowing it to dispense with the requirement for a Betasatellite. The implications of these findings in relation to the evolution of monopartite begomoviruses are discussed.

  • suppression of methylation mediated transcriptional gene silencing by βc1 sahh protein interaction during geminivirus Betasatellite infection
    PLOS Pathogens, 2011
    Co-Authors: Xiuling Yang, Yan Xie, Priya Raja, Jamie N Wolf, Qingtang Shen, David M Bisaro, Xueping Zhou
    Abstract:

    DNA methylation is a fundamental epigenetic modification that regulates gene expression and represses endogenous transposons and invading DNA viruses. As a counter-defense, the geminiviruses encode proteins that inhibit methylation and transcriptional gene silencing (TGS). Some geminiviruses have acquired a Betasatellite called DNA β. This study presents evidence that suppression of methylation-mediated TGS by the sole Betasatellite-encoded protein, βC1, is crucial to the association of Tomato yellow leaf curl China virus (TYLCCNV) with its Betasatellite (TYLCCNB). We show that TYLCCNB complements Beet curly top virus (BCTV) L2- mutants deficient for methylation inhibition and TGS suppression, and that cytosine methylation levels in BCTV and TYLCCNV genomes, as well as the host genome, are substantially reduced by TYLCCNB or βC1 expression. We also demonstrate that while TYLCCNB or βC1 expression can reverse TGS, TYLCCNV by itself is ineffective. Thus its AC2/AL2 protein, known to have suppression activity in other geminiviruses, is likely a natural mutant in this respect. A yeast two-hybrid screen of candidate proteins, followed by bimolecular fluorescence complementation analysis, revealed that βC1 interacts with S-adenosyl homocysteine hydrolase (SAHH), a methyl cycle enzyme required for TGS. We further demonstrate that βC1 protein inhibits SAHH activity in vitro. That βC1 and other geminivirus proteins target the methyl cycle suggests that limiting its product, S-adenosyl methionine, may be a common viral strategy for methylation interference. We propose that inhibition of methylation and TGS by βC1 stabilizes geminivirus/Betasatellite complexes.

  • Suppression of methylation-mediated transcriptional gene silencing by βC1-SAHH protein interaction during Geminivirus-Betasatellite Infection. PLoS Pathog. 7:e1002329. doi: 10.1371/journal.ppat.1002329
    2011
    Co-Authors: Xiuling Yang, Yan Xie, Priya Raja, Jamie N Wolf, Qingtang Shen, David M Bisaro, Xueping Zhou
    Abstract:

    DNA methylation is a fundamental epigenetic modification that regulates gene expression and represses endogenous transposons and invading DNA viruses. As a counter-defense, the geminiviruses encode proteins that inhibit methylation and transcriptional gene silencing (TGS). Some geminiviruses have acquired a Betasatellite called DNA b. This study presents evidence that suppression of methylation-mediated TGS by the sole Betasatellite-encoded protein, bC1, is crucial to the association of Tomato yellow leaf curl China virus (TYLCCNV) with its Betasatellite (TYLCCNB). We show that TYLCCNB complements Beet curly top virus (BCTV) L2- mutants deficient for methylation inhibition and TGS suppression, and that cytosine methylation levels in BCTV and TYLCCNV genomes, as well as the host genome, are substantially reduced by TYLCCNB or bC1 expression. We also demonstrate that while TYLCCNB or bC1 expression can reverse TGS, TYLCCNV by itself is ineffective. Thus its AC2/AL2 protein, known to have suppression activity in other geminiviruses, is likely a natural mutant in this respect. A yeast two-hybrid screen of candidate proteins, followed by bimolecular fluorescence complementation analysis, revealed that bC1 interacts with S-adenosyl homocysteine hydrolase (SAHH), a methyl cycle enzyme required for TGS. We further demonstrate that bC1 protein inhibits SAHH activity in vitro. That bC1 and other geminivirus proteins target the methyl cycle suggests that limiting its product, S-adenosyl methionine, may be a common viral strategy for methylatio

Jitesh Kumar - One of the best experts on this subject based on the ideXlab platform.

  • Association of Satellites with a Mastrevirus in Natural Infection: Complexity of Wheat Dwarf India Virus Disease
    2016
    Co-Authors: Jitendra Kumar, Jitesh Kumar, Sudhir P. Singh, Rakesh Tuli
    Abstract:

    In contrast to begomoviruses, mastreviruses have not previously been shown to interact with satellites. This study reports the first identification of the association of satellites with a mastrevirus in field-grown plants. Two alphasatellite species were de-tected in different field samples of wheat infected withWheat dwarf India virus (WDIV), a Cotton leaf curl Multan alphasatel-lite (CLCuMA) and a Guar leaf curl alphasatellite (GLCuA). In addition to the alphasatellites, a Betasatellite, Ageratum yellow leaf curl Betasatellite (AYLCB), was also identified in the wheat samples. No begomovirus was detected in the wheat samples, thus establishing association of the above-named satellites withWDIV. Agrobacterium-mediated inoculation ofWDIV in wheat, in the presence of either of the alphasatellites or the Betasatellite, resulted in infections inducing more severe symptoms.WDIV efficiently maintained each of the alphasatellites and the Betasatellite in wheat. The satellites enhanced the level ofWDIVDNA in wheat. Inoculation of the satellites isolated from wheat with various begomoviruses intoNicotiana tabacum demonstrated that these remain capable of interacting with the viruses with which they were first identified. Virus-specific small RNAs accu-mulated in wheat upon infection withWDIV but were lower in abundance in plants coinfected with the satellites, suggesting that both the alphasatellites and the Betasatellite suppress RNA silencing. These results suggest that the selective advantage for the maintenance of the alphasatellites and the Betasatellite byWDIV in the field is in overcoming RNA silencing-mediated host defense

  • senna leaf curl virus a novel begomovirus identified in senna occidentalis
    Archives of Virology, 2016
    Co-Authors: Anshu Alok, Rakesh Tuli, Jitesh Kumar, Jitendra Kumar
    Abstract:

    Begomoviruses are whitefly-transmitted, single-stranded DNA viruses that infect a variety of cultivated (crop) and non-cultivated (weed) plants. The present study identified a novel begomovirus and satellites (alpha- and Betasatellite) in Senna occidentalis (syn. Cassia occidentalis) showing leaf curl symptoms. The begomovirus shared a maximum sequence identity of 88.6 % with french bean leaf curl virus (JQ866297), whereas the alphasatellite and the Betasatellite shared identities of 98 % and 90 % with ageratum yellow vein India alphasatellite (LK054802) and papaya leaf curl Betasatellite (HM143906), respectively. No other begomovirus or satellites were detected in the suspected plants. We propose to name the virus “senna leaf curl virus” (SenLCuV).

  • βc1 is a pathogenicity determinant not only for begomoviruses but also for a mastrevirus
    Archives of Virology, 2014
    Co-Authors: Jitendra Kumar, Jitesh Kumar, Sudhir P. Singh, Rakesh Tuli
    Abstract:

    βC1 proteins, encoded by Betasatellites, are known to be pathogenicity determinants, and they are responsible for symptom expression in many devastating diseases caused by begomoviruses. We report the involvement of βC1 in pathogenicity determination of a mastrevirus. Analysis of field samples of wheat plants containing wheat dwarf India virus (WDIV) revealed the presence of a full-length and several defective Betasatellite molecules. The detected Betasatellite was identified as ageratum yellow leaf curl Betasatellite (AYLCB). No begomovirus was detected in any of the samples. The full-length AYLCB contained an intact βC1 gene, whereas the defective molecules contained complete or partial deletions of βC1. Agroinoculation of wheat with the full-length AYLCB and WDIV or of tobacco with ageratum enation virus enhanced the pathogenicity and accumulation of the respective viruses, whereas the defective molecules could not. This study indicates that βC1 is a pathogenicity determinant for WDIV and can interact functionally not only with begomoviruses but also with a mastrevirus.

  • association of satellites with a mastrevirus in natural infection complexity of wheat dwarf india virus disease
    Journal of Virology, 2014
    Co-Authors: Jitesh Kumar, Sudhir P. Singh, Rakesh Tuli
    Abstract:

    In contrast to begomoviruses, mastreviruses have not previously been shown to interact with satellites. This study reports the first identification of the association of satellites with a mastrevirus in field-grown plants. Two alphasatellite species were detected in different field samples of wheat infected with Wheat Dwarf India Virus (WDIV), a Cotton leaf curl Multan alphasatellite (CLCuMA) and a Guar leaf curl alphasatellite (GLCuA). In addition to the alphasatellites, a Betasatellite, Ageratum yellow leaf curl Betasatellite (AYLCB), was also identified in the wheat samples. No begomovirus was detected in the wheat samples, thus establishing association of the above-named satellites with WDIV. Agrobacterium-mediated inoculation of WDIV in wheat, in the presence of either of the alphasatellites or the Betasatellite, resulted in infections inducing more severe symptoms. WDIV efficiently maintained each of the alphasatellites and the Betasatellite in wheat. The satellites enhanced the level of WDIV DNA in wheat. Inoculation of the satellites isolated from wheat with various begomoviruses into Nicotiana tabacum demonstrated that these remain capable of interacting with the viruses with which they were first identified. Virus-specific small RNAs accumulated in wheat upon infection with WDIV but were lower in abundance in plants coinfected with the satellites, suggesting that both the alphasatellites and the Betasatellite suppress RNA silencing. These results suggest that the selective advantage for the maintenance of the alphasatellites and the Betasatellite by WDIV in the field is in overcoming RNA silencing-mediated host defense. IMPORTANCE Wheat is the most widely cultivated cereal crop in the world. A number of viruses are important pathogens of wheat, including the viruses of the genus Mastrevirus, family Geminiviridae. This study reports the association of subgenomic components, called satellites (alpha- and Betasatellites), with a mastrevirus, Wheat Dwarf India Virus (WDIV), isolated from two distant locations in India. This study reports the first identification of the satellites in a monocot plant. The satellites enhanced accumulation of WDIV and severity of disease symptoms. The satellites lowered the concentration of virus-specific small RNAs in wheat plants, indicating their silencing suppressor activity. The involvement of the satellites in symptom severity of the mastrevirus can have implications in the form of economic impact of the virus on crop yield. Understanding the role of the satellites in disease severity is important for developing disease management strategies.

  • 1 Association of satellites with a mastrevirus in natural infection: complexity of 1 Wheat dwarf India virus disease 2 3
    2014
    Co-Authors: Jitendra Kumar, Jitesh Kumar, Sudhir P. Singh, Rakesh Tuli
    Abstract:

    ABSTRACT 23 In contrast to begomoviruses, mastreviruses have not previously been shown to interact with 24 satellites. This manuscript reports the first identification of the association of satellites with a 25 mastrevirus in field-grown plants. Two alphasatellite species were detected in different field 26 samples of wheat infected with Wheat dwarf India virus (WDIV)- one Cotton leaf curl Multan 27 alphasatellite (CLCuMA) and the other Guar leaf curl alphasatellite (GLCuA). In addition to the 28 alphasatellites, a Betasatellite, Ageratum yellow leaf curl Betasatellite (AYLCB), was also 29 identified in the wheat samples. No begomovirus was detected in the wheat samples, thus 30 establishing association of the above satellites with WDIV. Agrobacterium-mediated inoculation 31 of WDIV in wheat, in the presence of either of the alphasatellites or the Betasatellite, resulted in 32 infections inducing more severe symptoms. WDIV efficiently maintained each of the 33 alphasatellites and the Betasatellite in wheat. The satellites enhanced the level of WDIV DNA in 34 wheat. Inoculation of the satellites isolated from wheat with various begomoviruses into 35 Nicotiana tabacum demonstrated that these remain capable of interacting with the viruses with 36 which they were first identified. Virus-specific small RNAs accumulated in wheat upon infection 3