Taxonomic Repositioning of Xanthomonas campestris pv. viticola (Nayudu 1972) Dye 1978 as Xanthomonas citri pv. viticola (Nayudu 1972) Dye 1978 comb. nov. and Emendation of the Description of Xanthomonas citri pv. anacardii to Include Pigmented Isolates Pathogenic to Cashew Plant

Abstract

Grapevine bacterial canker, which is caused by Xanthomonas campestris pv. viticola, is one of the most important grapevine diseases in the northeastern region of Brazil. This disease causes severe damage and represents a high potential risk to the development of Brazilian viticulture. In turn, pigmented isolates pathogenic to cashew plant, making cashew fruit unfit for sale, also have been detected in Northeastern Brazil. Given that the taxonomic position of these bacteria is unclear, the multilocus sequence analysis (MLSA) technique, average nucleotide identity (ANI) values and tetranucleotide frequency correlation coefficients (TETRA) were used to analyze their phylogenetic relationship in relation to other Xanthomonas species. X. campestris pv. viticola was closely related to X. citri pv. mangiferaeindicae (repetitive-polymerase chain reaction [rep-PCR], MLSA, and ANI) and X. citri subsp. citri (MLSA and ANI). Pigmented isolates pathogenic to cashew plant were closely related to X. citri pv. anacardii (rep-PCR, MLSA, ANI, and TETRA). The results obtained in this study support the emendation of the description of X. citri pv. anacardii to include pigmented isolates of Xanthomonas pathogenic to cashew plant. In addition, the reclassification of X. campestris pv. viticola as X. citri pv. viticola comb. nov. is suggested.

Comparative genome analysis and phylogenomic of Xanthomonas citri pv. viticola lead to new taxonomic insights about species of Xanthomonas

“…Although Xanthomonas phylogeny has been extensively analyzed and is considered well defined using the MLSA technique [4,9,33], Amplified fragment length polymorphism (AFLP) [34], 16S rDNA region sequencing [35], and rep-PCR [36], genomic approaches have shown that significant uncertainties remain, regarding the boundaries of the genus and the taxonomic position of some taxa [4,37]. Additionally, many other plant pathogenic bacteria [13,38,39] do not have their identifications updated with more modern techniques [13].…”

“…Additionally, many other plant pathogenic bacteria [13,38,39] do not have their identifications updated with more modern techniques [13]. Studies of the genome-based phylogenetic have suggested a reconstruction and substantial changes in the nomenclature of the genus Xanthomonas resolving previous conflicting results based on MLSA and subspecies and pathovar assignment [4,9,37].…”

“…viticola (synonym Xanthomonas campestris pv. viticola) was recently proposed using a polyphasic approach that included analysis of whole-genome sequences such as Average Nucleotide Identity (ANI) and tetranucleotide frequencies (TETRA) [4]. It is believed that this bacterium has been introduced in Brazil with propagating material from India to the Valley of the São Francisco River in the states of Pernambuco and Bahia [5].…”

“…The genomics era has revolutionized the field of bacteriology [8] by allowing accession to the complete genome of an organism at an unprecedented rate and scale. Whole-genome sequencing associated with comparative analysis has provided valuable insights and knowledge about taxonomic positions of Xanthomonas species and pathovars [4,9,10]. Thus, the last years have been marked by the replacement of wet lab technique DNA-DNA hybridization (DDH) by genomic-based taxonomic analyses using several algorithms, such as the average nucleotide identity based on BLAST (ANIb) or MUMmer algorithms (ANIm) [11] and in silico DDH based in the distance between genomes (Meier-Kolthoff et al 2013).…”

Bacterial etiology of necrotic spots on leaves and shoots of grapevine (Vitis vinifera L.) in Poland

“…viticola (leaf spot and bacterial canker) (Chand and Kishun 1990;Lima et al 1999;Neto et al 2011). Due to the unclear taxonomic position of the last of these pathogens, Gama et al (2018), based on extensive molecular studies, proposed its reposition on Xanthomonas citri pv. viticola.…”