Phytoplasmas are wall-less obligate parasites of plants and insects. Several phytoplasma strains within the Peanut Witches’ Broom (PWB; 16SrII) group are associated with significant disease losses across diverse crops and weeds. We present complete, single contig genome assemblies for two Indian parthenium phyllody strains, ‘Candidatus Phytoplasma asiaticum’ PR34 and ‘Ca. P. australasiaticum’ PR08, generated through host DNA depletion and hybrid Illumina–Nanopore sequencing. Both genomes display characteristic features of reductive evolution (∼614 kb and 589 kb, respectively) but show notable differences from previously sequenced PWB phytoplasmas. In contrast to most of PMU-rich phytoplasma genomes, neither PR34 nor PR08 retains intact Potential Mobile Units. Instead, both harbor numerous open reading frames encoding group II intron reverse transcriptase/ maturase proteins, predominantly of the mitochondrial-like type, with PR34 containing 52 and PR08 28 such loci that together constitute > 4% of each genome. These observations support the hypothesis that intron-associated processes may contribute to genome variability in the absence of canonical PMUs. Comparative analyses support the classification of PR34 as a distinct species within the PWB complex and reveal both conserved Sec-dependent effectors (SAP05, SAP11, and SAP54/PHYL1) and lineage-specific secreted proteins with predicted nuclear localization. Additional retained features include functional sodA genes and multiple truncated HlyB-like transporters. Collectively, these high-quality genomes illustrate a genomic configuration in which extensive genome reduction and loss of PMUs coexist with the retention of core virulence factors and an expanded repertoire of group II introns, providing a framework for future investigation of genome plasticity in phytoplasmas.

A Gram-stain-negative, aerobic, non-motile, rod-shaped, and orange-pigmented bacterium, designated CJ426^T, was isolated from ginseng soil in Anseong, Korea. Strain CJ426^T grew optimally on Reasoner’s 2A agar at 30°C and pH 7.0 in the absence of NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain CJ426^T belonged to the family Chitinophagaceae and had the highest sequence similarity with Niabella hibiscisoli KACC 18857^T (98.7%). The 16S rRNA gene sequence similarities with other members of the genus Niabella ranged from 92.3% to 98.1%. Phylogenomic analyses and overall genomic relatedness indices, including average nucleotide identity, average amino acid identity, and the percentage of conserved proteins values, supported the classification of strain CJ426^T as a representative of a novel genus within the family Chitinophagaceae. Furthermore, genome-based analyses suggested that five members of the genus Niabella, including N. aquatica, N. defluvii, N. ginsengisoli, N. hibiscisoli, and, N. yanshanensis, should be separated from other Niabella species and be assigned as a novel genus. The major isoprenoid quinone of strain CJ426^T was menaquinone-7 (MK-7). The predominant polar lipids were phosphatidylethanolamine and six unidentified aminolipids. The major fatty acids were iso-C_15:0, iso-C_15:1 G, and iso-C_17:0 3-OH. The genome of strain CJ426^T was 6.3 Mbp in size, consisting of three contigs, with a G + C content of 41.9%. Based on a polyphasic taxonomic approach, strain CJ426^T represents a novel genus and species within the family Chitinophagaceae, for which the name Paraniabella aurantiaca gen. nov., sp. nov. is proposed. The type strain is CJ426^T (= KACC 23908^T = JCM 37728^T).