Identification and genomic characterization of a novel tobamovirus from prickly pear cactus

[EN] In this work, we describe the complete sequence and genome organization of a novel tobamovirus detected in a prickly pear plant (Opuntia sp.) by high-throughput sequencing, tentatively named "opuntia virus 2". The full genome of opuntia virus 2 is 6,453 nucleotides in length and contains four open reading frames (ORFs) coding for the two subunits of the RNA polymerase, the movement protein, and the coat protein, respectively. Phylogenetic analysis using the complete nucleotide sequence revealed that the virus belongs to the genus Tobamovirus (family Virgaviridae), showing the highest nucleotide sequence identity (49.8%) with cactus mild mottle virus (CMMoV), being indicating that it belongs in the Cactaceae subgroup of tobamoviruses.This study was funded by project no. IN216317 of UNAM-Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) and by Grant BIO2017-88321-R from the Spanish Agencia Estatal de Investigacion (AEI) and Fondo Europeo de Desarrollo Regional (FEDER).Salgado-Ortiz, H.; De La Torre-Almaraz, R.; Sanchez Navarro, JA.; Pallás Benet, V. (2020). Identification and genomic characterization of a novel tobamovirus from prickly pear cactus. Archives of Virology. 165(3):781-784. https://doi.org/10.1007/s00705-020-04528-3S7817841653Sánchez LDL, López GC, Ávalos HI (2013) Nomenclatura vernácula, uso y manejo de Opuntia spp. en Santiago Bayacora, Durango, México. Revista Chapingo Serie Horticultura 19:367–380Alonso BB, Mora AG, Valdovinos PG, Ochoa MDL, Rodríguez LE, De La Torre AR (2015) Asociación de un Potexvirus como agente causal de manchas cloróticas en Opuntia ficus-indica. Rev Mex Fitopatol 33:75–86De La Torre AR, Salgado OH, Salazar SM, Pallás V, Sánchez NJA, Valverde RA (2016) First report of Schlumbergera virus X in prickly pear (Opuntia ficus-indica) in Mexico. Plant Dis 100(8):1799De La Torre AR, Salgado OH, Salazar SM, Pallás V, Sánchez NJA, Valverde RA (2016) First report of Rattail cactus necrosis-associated virus in prickly pear fruit (Opuntia albicarpa Scheinvar) in Mexico. Plant Dis 100(11):2339Min BE, Chung BN, Kim MJ, Ha JH, Lee BY, Ryu KH (2006) Cactus mild mottle virus is a new cactus-infecting tobamovirus. Arch Virol 151(1):13–21Kim NR, Hong JS, Song YS, Chung BN, Park JW, Ryu KH (2012) The complete genome sequence of a member of a new species of tobamovirus (rattail cactus necrosis-associated virus) isolated from Aporocactus flagelliformis. Arch Virol 157(1):185–187Adams MJ, Antoniw JF, Kreuze J (2009) Virgaviridae: a new family of rod-shaped plant viruses. Arch Virol 154(12):1967–1972. https://doi.org/10.1007/s00705-009-0506-6Lecoq H, Desbiez C (2012) Viruses of cucurbit crops in the Mediterranean region: an ever-changing picture. Adv Virus Res 84:67–126Haas BJ, Papanicolaou A, Yassour M, Grabherr M, Blood PD, Bowden J, Regev A (2013) De novo transcript sequence reconstruction from RNA-Seq: reference generation and analysis with Trinity. Nat Protoc 8(8):1–43Altschul SF, Madden TL, Schäffer AA, Zhang J, Zhang Z, Miller W, Lipman DJ (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 25:3389–3402Kumar S, Stecher G, Tamura K (2016) MEGA7: molecular evolutionary genetics analysis version 7.0 for bigger datasets. Mol Biol Evol 33(7):1870–1874Song YS, Min BE, Hong JS, Rhie MJ, Kim MJ, Ryu KH (2006) Molecular evidence supporting the confirmation of Maracuja mosaic virus as a species of the genus Tobamovirus and production of an infectious cDNA transcript. Arch Virol 151:2337–2348Gibbs AJ, Wood J, Garcia-Arenal F, Ohshima K, Armstrong JS (2015) Tobamoviruses have probably co-diverged with their eudicotyledonous hosts for at least 110 million years. Virus Evol 1(1):vev019Adams MJ, Adkins S, Blagard C et al (2018) International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Virgaviridae. http://www.ictv.global/report/virgaviridae. Accessed 19 Oct 201

Ocurrencia de un tobamovirus asociado con manchas anulares amarillas en nopal tunero en méxico

Se detectó un virus en cladodios de nopal tunero cultivado en la región de San Martín de las Pirámides, Estado de México, con manchas anulares de color amarillo. Los cladodios afectados desarrollan, en ataques severos, clorosis y marchitez. El virus se transmitió mecánicamente a algunas especies de plantas hospedantes indicadoras, causando lesiones locales cloróticas y después necróticas en las hojas inoculadas; sólo Nicotiana tabacum L. var. White Burley y Capsicum annuum L. desarrollaron además mosaicos tenues en hojas no inoculadas. El desarrollo de síntomas en los hospedantes alternos fue lento, pero se aceleraron a temperaturas mayores a 30 °C en invernadero. El análisis electroforético y el tratamiento con nucleasas del ARN replicativo mostró que el virus aislado de plantas de nopal tiene un genoma de ARN de cadena sencilla, mientras que el análisis al microscopio electrónico de macerados de tejidos de plantas de las especies de hospedantes indicadoras con mosaico, mostró partículas en forma de varilla rígida de 300-350 nm de longitud. Además, el ensayo por RT-PCR confirmó que el virus es una especie del grupo Tobamovirus. Las características biológicas de este virus indicaron que es una variante no severa relacionada con la especie Opuntia Sammons¿ virus

Ocurrencia de hongos y etiología de la secadera de la fresa con diferentes sistemas de manejo agronómico

In México, strawberry dry wilt (Fragaria x ananassa) has been associated with a fungus complex in which only the implication of Fusarium oxysporum (Fox) is evident. Therefore, in the present study the association of fungi and pseudofungi with the disease was determined in different systems of agronomical management, and pathogenicity was verified. Two samplings were made in the 2002/03 season and three in 2003/04 in 16 localities of the Valley of Zamora, Michoacán, México, where 2640 sections of roots and 365 of necrotic crowns were sown, along with 400 sections of asymptomatic tissue in potato-dextrose-agar (PDA) culture medium and a selective medium with antibiotics and PCNB (PARPH) fungicide. Fox, F. solani (Fso), Cylindrocarpon sp. (Cyl), Pythium aphanidermatum (Pyt), Phytophthora sp. (Phy), Rhizoctonia fragariae (Rhi), Verticillium albo-atrum (Ver) and Colletotrichum sp. (Col) were associated with the dry wilt. Fox was the most frequent species (p=0.05) and the only one that showed an increase from flowering to fructification of 47 to 62% in root and 77 to 83% in crown. In plantations with plastic mulch and drip irrigation (A + G), Fox decreased by 18% with respect to unmulched soil with gravity irrigation, whereas Cyl increased by 15% in A + G (p=0.05). The clay and clay loam soil contrasted in the detection of Fox (46.8 and 12.4%) and Rhi (9.1 and 43.7%). Symptoms of wilting with necrosis in root and crown and general death were reproduced with individual inoculations of Fox (100%), Pyt (100%), Phy (100%), Rhi (60%) and combinations of Fox with Rhi (100%), Pyt (100%) and Cyl (100%). This is the first report that implies Phytophthora sp., P. aphanidermatum and R. fragariae as causal pathogens of dry wilt in México. The morphological identification of Fox and Rhi was confirmed by sequencing of the intergenic region of the rDNA