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Volume 11, Issue 4

Sequencing and comparative analyses of ‘ Phytoplasma solani’ genomes reveal diversity of effectors and potential mobile units Open Access

Abstract

Phytoplasmas (genus ‘ Phytoplasma’) encompass a group of uncultivated bacteria affecting numerous plant species and causing significant damage in agriculture worldwide. They have a dual parasitic cycle, including colonization of both plant phloem and insect cells. Their genomes are small, diverse, repetitive, prone to rearrangements and harbour transposon-like elements known as potential mobile units (PMUs). In the Euro-Mediterranean region, ‘. P. solani’ is an important species due to its broad range of plant hosts and insect vectors. To provide insights into the genomic diversity of this species, particularly the repertoire of putative effectors and PMUs, this study conducted genome sequencing and analyses of two . P. solani’ strains originating from different plants and transmitted by different insects. Based on assembly, we obtained 19 contigs totalling 656 141 bp for strain STOL and 28 contigs totalling 707 036 bp for strain ST19. The prevalence of repetitive sequences and PMUs contributed to the fragmentation of these draft assemblies. The annotation identified 28 and 26 genes that encode putative secreted proteins in these two strains, respectively, including several homologues of previously characterized phytoplasma effectors. Our comparative analyses further identified species- and strain-specific genes. Frequently, genes that encode putative secreted proteins and effectors were found within PMU-like regions in both genomes. Moreover, strain STOL showed characteristics of a more reduced genome, having fewer PMU-like repetitive elements and genome rearrangements, while strain ST19 exhibited a higher level of sequence divergence in its PMU genes. The high levels of genomic diversity among ‘. P. solani’ strains suggested rapid evolution of this species, which may contribute to its wide host range and adaptability potential. This study provides novel data on the diversification of ‘. P. solani’ genomes. These results provide a foundation for future functional studies of putative effectors and their interactions with host targets, which could facilitate deciphering the pathogenicity strategies of this successful and versatile pathogen.

  • Received:
  • Accepted:
  • Published Online:
Keyword(s): effector proteins , mobile genetic elements , pathogenicity , phytoplasma , plant pathogens and virulence factors
Funding
This study was supported by the:
  • Academia Sinica
    • Principal Award Recipient: Chih-HorngKuo
  • Hrvatska Zaklada za Znanost (Award IP-2019-04-2469)
    • Principal Award Recipient: MartinaŠeruga Musić
© 2025 The Authors
  • This is an open-access article distributed under the terms of the Creative Commons Attribution License. This article was made open access via a Publish and Read agreement between the Microbiology Society and the corresponding author’s institution.
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2026-03-09

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Sequencing and comparative analyses of ‘Candidatus Phytoplasma solani’ genomes reveal diversity of effectors and potential mobile units
M Gen 11, 001401 (2025); https://doi.org/10.1099/mgen.0.001401
/content/journal/mgen/10.1099/mgen.0.001401
/content/journal/mgen/10.1099/mgen.0.001401
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